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Polymers and Polymer Composites: Structure-Property Relationship
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Polymers and Polymer Composites: Structure-Property Relationship

A topical collection in Polymers (ISSN 2073-4360). This collection belongs to the section "Polymer Composites and Nanocomposites".

Viewed by 44907

Editor

Dr. Shaojian He

E-Mail Website
Collection Editor
Beijing Key Laboratory of Energy Safety and Clean Utilization, North China Electric Power University, Beijing 102206, China
Interests: polymer insulation materials; high-performance rubber nanocomposites; energy materials
Special Issues, Collections and Topics in MDPI journals

Topical Collection Information

Dear Colleagues,

We cordially invite you to submit your research papers, communications, or review articles to a Topical Collection of Polymers entitled “Polymers and Polymer Composites: Structure-Property Relationship”. Polymers and polymer composite materials have been widely applied in our daily lives and in industrial fields. Due to the significant expansion in the use of newly developed polymers and polymer composite materials, it is necessary to understand and accurately describe the relationship between material structure and properties, as only based on thorough laboratory characterization is it possible to estimate the properties for their future commercial applications. The aim of this Topical Collection is to address the recent developments of structural/functional polymers and their composites, including fundamental structure-property relationships, preparation methods, synthesis routes, simulation models, basic mechanical properties, functional performance (heat, electrical, photoelectric, magnetic, etc.) and advanced application in daily life/industrial fields.

We are looking forward to receiving your outstanding work on this Topical Collection.

Dr. Shaojian He
Collection Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the collection website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Polymers is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • polymer
  • composites
  • microstructure
  • preparation
  • properties
  • application
  • plastics
  • rubber
  • membrane

Published Papers (27 papers)

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2024

Jump to: 2023, 2022

14 pages, 9830 KiB  
Article
The Preparation and Performance of Epoxy/Acetylene Carbon Black Wave-Absorbing Foam
by Xiaoli Liu, Hao Huang and Haijun Lu
Polymers 2024, 16(8), 1074; https://doi.org/10.3390/polym16081074 - 12 Apr 2024
Viewed by 317
Abstract
The epoxy foam material filled with an absorbing agent effectively absorbs electromagnetic waves. In this study, epoxy resin was used as the matrix, and acetylene carbon black was used as the magnetic absorbing agent to prepare an absorbing foam material (epoxy/CB). The microstructure [...] Read more.
The epoxy foam material filled with an absorbing agent effectively absorbs electromagnetic waves. In this study, epoxy resin was used as the matrix, and acetylene carbon black was used as the magnetic absorbing agent to prepare an absorbing foam material (epoxy/CB). The microstructure of acetylene carbon black (CB) and its distribution in epoxy resin, as well as the effects of pre-polymerization time and CB content on the foam structure, were systematically characterized. Additionally, two dispersion methods, the hot-melt in situ stirring dispersion method and the three-roll milling dispersion method, were studied for their effects on the foaming process and absorbing properties of epoxy/CB. The results showed that with the prolongation of pre-polymerization time, the pore size decreased from 1.02 mm to 0.4 mm, leading to a more uniform pore distribution. Compared to the hot-melt in situ stirring dispersion method, the three-roll milling dispersion method effectively improved the dispersion of CB in epoxy resin, reducing the aggregate size from 300–400 nm to 70–80 nm. The pore diameter also decreased from 0.453 mm to 0.311 mm, improving the uniformity of particle size distribution. However, the absorbing material prepared with the three-roll milling dispersion method exhibited unsatisfactory absorption performance, with values close to 0 dB at mid-low frequencies and around −1 dB at high frequencies. In contrast, the absorbing material prepared with the hot-melt in situ stirring dispersion method showed better absorption performance at high frequencies, reaching around −9 dB. Full article
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12 pages, 2867 KiB  
Article
Effect of Methyl Hydro-Silicone Oil Content and Aging Time on Compression Modulus and Breakdown Strength of Additional Liquid Silicone Rubber Gel
by Kun Wang, Yun Chen, Wei Yang, Bo Qiao, Jian Qiao, Jianfei He and Qinying Ning
Polymers 2024, 16(6), 763; https://doi.org/10.3390/polym16060763 - 10 Mar 2024
Viewed by 761
Abstract
The performance of silicone rubber gel elastomers is affected by the composition and structure of the crosslinker. In this work, a two-component addition liquid silicone rubber gel material was developed, and the effects of the contents of two methyl hydro-silicone oils on the [...] Read more.
The performance of silicone rubber gel elastomers is affected by the composition and structure of the crosslinker. In this work, a two-component addition liquid silicone rubber gel material was developed, and the effects of the contents of two methyl hydro-silicone oils on the compression modulus and breakdown strength of the silicone rubber gel insulating material, as well as the performance change after hot air aging at different times (24 h, 48 h, 72 h, 96 h, 120 h, 144 h, 168 h), were studied. The results showed that the breakdown strength and compression modulus exhibited an upward trend with the increase in the hydrogen silicone oil content. The best performance was achieved in the silicone rubber gel with Si-H:Si-Vi = 1.4:1. Moreover, with the increase in aging time, the breakdown strength decreased and the compression modulus increased. Full article
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23 pages, 21120 KiB  
Article
Post-Heat Flexural Properties of Siloxane-Modified Epoxy/Phenolic Composites Reinforced by Glass Fiber
by Yundong Ji, Xinchen Zhang, Changzeng Wang, Shuxin Li and Dongfeng Cao
Polymers 2024, 16(5), 708; https://doi.org/10.3390/polym16050708 - 05 Mar 2024
Cited by 1 | Viewed by 648
Abstract
The post-heat mechanical property is one of the important indices for the fire-resistance evaluation of fiber-reinforced polymers. At present, the primary approach to improving the post-heat mechanical property of a material involves incorporating inorganic fillers; yet, the enhancement is limited, and is accompanied [...] Read more.
The post-heat mechanical property is one of the important indices for the fire-resistance evaluation of fiber-reinforced polymers. At present, the primary approach to improving the post-heat mechanical property of a material involves incorporating inorganic fillers; yet, the enhancement is limited, and is accompanied by a reduction in room-temperature performance and processability. This study prepares glass-fiber-reinforced composites with elevated mechanical properties after heat through utilizing two variants of epoxy resins modified with polysiloxane, phenolic resin, kaolin, and graphite. In comparison to the phenolic samples, the phenylpropylsiloxane-modified epoxy resulted in a 115% rise in post-heat flexural strength and a 70% increase in the room-temperature flexural strength of phenolic composites. On the other hand, dimethylsiloxane-modified epoxy leads to a 117% improvement in post-heat flexural strength but a 44% decrease in the room-temperature flexural strength of phenolic composites. Macroscopic/microscopic morphologies and a residual structure model of the composites after heat reveal that, during high temperature exposure, the pyrolysis products of polysiloxane promote interactions between carbon elements and fillers, thus preserving more residues and improving the dimensional stability as well as the density of materials. Consequently, a notable enhancement is observed in both the post-heat flexural strength and the mass of carbon residue after the incorporation of polysiloxane and fillers into the materials. The pyrolysis products of polysiloxane-modified epoxy play a vital role in enhancing the post-heat flexural strength by promoting carbon retention, carbon fixation, and interactions with fillers, offering novel pathways for the development of advanced composites with superior fire-resistance properties. Full article
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11 pages, 5896 KiB  
Article
Preparation, Structure and Properties of Epoxy/Carbonyl Iron Powder Wave-Absorbing Foam for Electromagnetic Shielding
by Xiaoli Liu, Hao Huang and Haijun Lu
Polymers 2024, 16(5), 698; https://doi.org/10.3390/polym16050698 - 04 Mar 2024
Viewed by 695
Abstract
The application of absorbing materials for electromagnetic shielding is becoming extensive, and the use of absorbents is one of the most important points of preparing absorbing foam materials. In this work, epoxy resin was used as the matrix and carbonyl iron powder (CIP) [...] Read more.
The application of absorbing materials for electromagnetic shielding is becoming extensive, and the use of absorbents is one of the most important points of preparing absorbing foam materials. In this work, epoxy resin was used as the matrix and carbonyl iron powder (CIP) was used as the absorbent, and the structural absorbing foam materials were prepared by the ball mill dispersion method. Scanning electron microscopy showed that the CIP was evenly dispersed in the resin matrix. The foam structures formed at pre-polymerization times of 10 min, 30 min and 50 min were analyzed, and it was found that the cell diameter decreased from 0.47 mm to 0.31 mm with the increase in the pre-polymerization time. The reflectivity of the frontal and reverse sides of the foam gradually tends to be unified at frequencies of 2–18 GHz. When the CIP content increased from 30 wt% to 70 wt%, the cell diameter increased from 0.32 mm to 0.4 mm, and the uniformity of CIP distribution deteriorated. However, with the increase in the CIP content, the absorption properties of the composite materials were enhanced, and the absorption frequency band broadened. When the CIP content reached 70 wt%, the compression strength and modulus of the foam increased to 1.32 MPa and 139.0 MPa, respectively, indicating a strong ability to resist deformation. Full article
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2023

Jump to: 2024, 2022

19 pages, 6625 KiB  
Article
On the Effect of Non-Thermal Atmospheric Pressure Plasma Treatment on the Properties of PET Film
by Irena Maliszewska, Małgorzata Gazińska, Maciej Łojkowski, Emilia Choińska, Daria Nowinski, Tomasz Czapka and Wojciech Święszkowski
Polymers 2023, 15(21), 4289; https://doi.org/10.3390/polym15214289 - 31 Oct 2023
Cited by 1 | Viewed by 1131
Abstract
The aim of the work was to investigate the effect of non-thermal plasma treatment of an ultra-thin polyethylene terephthalate (PET) film on changes in its physicochemical properties and biodegradability. Plasma treatment using a dielectric barrier discharge plasma reactor was carried out in air [...] Read more.
The aim of the work was to investigate the effect of non-thermal plasma treatment of an ultra-thin polyethylene terephthalate (PET) film on changes in its physicochemical properties and biodegradability. Plasma treatment using a dielectric barrier discharge plasma reactor was carried out in air at room temperature and atmospheric pressure twice for 5 and 15 min, respectively. It has been shown that pre-treatment of the PET surface with non-thermal atmospheric plasma leads to changes in the physicochemical properties of this polymer. After plasma modification, the films showed a more developed surface compared to the control samples, which may be related to the surface etching and oxidation processes. After a 5-min plasma exposure, PET films were characterized by the highest wettability, i.e., the contact angle decreased by more than twice compared to the untreated samples. The differential scanning calorimetry analysis revealed the influence of plasma pretreatment on crystallinity content and the melt crystallization behavior of PET after soil degradation. The main novelty of the work is the fact that the combined action of two factors (i.e., physical and biological) led to a reduction in the content of the crystalline phase in the tested polymeric material. Full article
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18 pages, 8672 KiB  
Article
Tensile Properties of Four Types of ABS Lattice Structures—A Comparative Study
by Katarina Monkova, Peter Pavol Monka, Romana Hricová, Berenika Hausnerova and Lucia Knapčíková
Polymers 2023, 15(20), 4090; https://doi.org/10.3390/polym15204090 - 15 Oct 2023
Cited by 1 | Viewed by 1133
Abstract
This article aims to compare the behaviour of four types of lattice structures named Cartesian, Rhomboid, Octagonal, and Starlit under tensile stress loading. The structures were made of Acrylonitrile Butadiene Styrene (ABS) material using the Fused Filament Fabrication (FFF) technique with three different [...] Read more.
This article aims to compare the behaviour of four types of lattice structures named Cartesian, Rhomboid, Octagonal, and Starlit under tensile stress loading. The structures were made of Acrylonitrile Butadiene Styrene (ABS) material using the Fused Filament Fabrication (FFF) technique with three different specific volumes (24, 42, and 60%). Five samples of each type were produced, and a total of 60 samples were tested. Experimental testing was performed according to EN ISO 527-1:2012 and EN ISO 527-2:2012. The obtained data were statistically processed, while no outliers were identified. The experimental results pointed out that the specimens’ topology, together with the specific volume, very significantly affected the resultant ABS properties of the tested samples made of the same material. The comparative study showed that in terms of ultimate strength, yield strength, and Young’s modulus, the Cartesian structure appeared to be the most suitable for tensile stress, and the least suitable structure was the Rhomboid structure. On the other hand, the Rhomboid-type of the structure showed not only the highest amount of absorbed energy but also the highest toughness among the investigated lattice structures, so in the near future, its behaviour under an impact test should be studied. Full article
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20 pages, 13951 KiB  
Article
The Effect of Conductive Polyaniline on the Anti-Fouling and Electromagnetic Properties of Polydimethylsiloxane Coatings
by Yarui Guo, Yuhong Qi, Chen Zhang, Shukun Zhang and Zhanping Zhang
Polymers 2023, 15(13), 2944; https://doi.org/10.3390/polym15132944 - 04 Jul 2023
Cited by 1 | Viewed by 1063
Abstract
In this paper, four conductive polyaniline powders doped in hydrochloric acid, sulfuric acid, phosphoric acid, and sulfonic acid were selected and blended with polydimethylsiloxane to prepare coatings with an electromagnetic absorption effect and fouling desorption effect, respectively. A UV spectrophotometer was used to [...] Read more.
In this paper, four conductive polyaniline powders doped in hydrochloric acid, sulfuric acid, phosphoric acid, and sulfonic acid were selected and blended with polydimethylsiloxane to prepare coatings with an electromagnetic absorption effect and fouling desorption effect, respectively. A UV spectrophotometer was used to evaluate the settling rate of the powders. Fourier transform infrared spectrometry, laser confocal microscopy, and scanning electron microscopy were used to observe the morphology and structure of the powder and the coating. The interface properties of the coatings were characterized using a contact angle measurement, the mechanical properties of the coatings using a tensile test, and the electromagnetic properties of the powders and microwave absorption properties of the coatings using vector network analyzers. Meanwhile, the antifouling performance of the coatings was evaluated via the marine bacteria adhesion test and benthic diatom adhesion test, and the effect of conductive polyaniline on the antifouling performance of the coating was analyzed. The results show that adding polyaniline reduced the surface energy of the coating and increased the roughness, mechanical properties and anti-fouling properties of the coating. Moreover, adding appropriate polyaniline powder can enhance the electromagnetic wave loss of the coating. The followings values were recorded for a hydrochloric-acid-doped polyaniline coating: lowest surface energy of 17.17 mJ/m2, maximum fracture strength of 0.95 MPa, maximum elongation of 155%, maximum bandwidth of 3.81 GHz, and peak of reflection loss of −23.15 dB. The bacterial detachment rate of the polydimethylsiloxane (PDMS) samples was only 30.37%. The bacterial adhesion rates of the composite coating containing hydrochloric-acid-doped polyaniline were 4.95% and 2.72% after rinsing and washing, respectively, and the desorption rate was 45.35%. The chlorophyll concentration values were 0.0057 mg/L and 0.0028 mg/L, respectively, and the desorption rate was 54.62%. Full article
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14 pages, 6519 KiB  
Article
Effect of SEBS Molecular Structure and Formula Composition on the Performance of SEBS/PP TPE for Automotive Interior Skin
by Shuwen Liu, Jun Qiu, Lili Han, Junping Luan, Xueyan Ma and Wenquan Chen
Polymers 2023, 15(12), 2753; https://doi.org/10.3390/polym15122753 - 20 Jun 2023
Cited by 1 | Viewed by 2008
Abstract
The hydrogenated styrene–butadiene–styrene block copolymer (SEBS)/Polypropylene (PP)-blended thermoplastic elastomer (TPE) is an ideal material for automotive interior skin applications due to its excellent elasticity, weather resistance, and environmentally friendly characteristics such as low odor and low volatile organic compounds (VOC). As a thin-wall [...] Read more.
The hydrogenated styrene–butadiene–styrene block copolymer (SEBS)/Polypropylene (PP)-blended thermoplastic elastomer (TPE) is an ideal material for automotive interior skin applications due to its excellent elasticity, weather resistance, and environmentally friendly characteristics such as low odor and low volatile organic compounds (VOC). As a thin-wall injection-molded appearance skin product, it requires both high fluidity and good mechanical properties with scratch resistance. To optimize the performance of the SEBS/PP-blended TPE skin material, an orthogonal experiment and other methods were employed to investigate the impact of the formula composition and raw material characteristics, such as the styrene content and molecular structure of SEBS, on the TPE’s final performance. The outcomes revealed that the ratio of SEBS/PP had the most significant influence on the mechanical properties, fluidity, and wear resistance of the final products. The mechanical performance was enhanced by increasing the PP content within a certain range. The degree of sticky touch on the TPE surface was increased as the filling oil content increased, causing the increase in sticky wear and the decrease in abrasion resistance. When the SEBS ratio of high/low styrene content was 30/70, the TPE’s overall performance was excellent. The different proportions of linear/radial SEBS also had a significant effect on the final properties of the TPE. The TPE exhibited the best wear resistance and excellent mechanical properties when the ratio of linear-shaped/star-shaped SEBS was 70/30. Full article
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11 pages, 5458 KiB  
Article
Tailored Dynamic Viscoelasticity of Polyurethanes Based on Different Diols
by Jiadong Wang, Min Wang, Chenxin Xu, Yang Han, Xuan Qin and Liqun Zhang
Polymers 2023, 15(12), 2623; https://doi.org/10.3390/polym15122623 - 09 Jun 2023
Cited by 1 | Viewed by 1144
Abstract
The development of damping and tire materials has led to a growing need to customize the dynamic viscoelasticity of polymers. In the case of polyurethane (PU), which possesses a designable molecular structure, the desired dynamic viscoelasticity can be achieved by carefully selecting flexible [...] Read more.
The development of damping and tire materials has led to a growing need to customize the dynamic viscoelasticity of polymers. In the case of polyurethane (PU), which possesses a designable molecular structure, the desired dynamic viscoelasticity can be achieved by carefully selecting flexible soft segments and employing chain extenders with diverse chemical structures. This process involves fine-tuning the molecular structure and optimizing the degree of micro-phase separation. It is worth noting that the temperature at which the loss peak occurs increases as the soft segment structure becomes more rigid. By incorporating soft segments with varying degrees of flexibility, the loss peak temperature can be adjusted within a broad range, from −50 °C to 14 °C. Furthermore, when the molecular structure of the chain extender becomes more regular, it enhances interaction between the soft and hard segments, leading to a higher degree of micro-phase separation. This phenomenon is evident from the increased percentage of hydrogen-bonding carbonyl, a lower loss peak temperature, and a higher modulus. By modifying the molecular weight of the chain extender, we can achieve precise control over the loss peak temperature, allowing us to regulate it within the range of −1 °C and 13 °C. To summarize, our research presents a novel approach for tailoring the dynamic viscoelasticity of PU materials and thus offers a new avenue for further exploration in this field. Full article
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19 pages, 5680 KiB  
Article
Synthesis and Properties of the Novel High-Performance Hydroxyl-Terminated Liquid Fluoroelastomer
by Donghan Li, Chen Yang, Ping Li, Lu Yu, Shufa Zhao, Long Li, Hailan Kang, Feng Yang and Qinghong Fang
Polymers 2023, 15(11), 2574; https://doi.org/10.3390/polym15112574 - 04 Jun 2023
Viewed by 1469
Abstract
Functional liquid fluoroelastomers are in high demand in new energy fields. And these materials have potential applications in high-performance sealing materials and as electrode materials. In this study, a novel high-performance hydroxyl-terminated liquid fluoroelastomer (t-HTLF) with a high fluorine content, temperature resistance, and [...] Read more.
Functional liquid fluoroelastomers are in high demand in new energy fields. And these materials have potential applications in high-performance sealing materials and as electrode materials. In this study, a novel high-performance hydroxyl-terminated liquid fluoroelastomer (t-HTLF) with a high fluorine content, temperature resistance, and curing efficiency was synthesised from a terpolymer of vinylidene fluoride (VDF), tetrafluoroethylene (TFE), and hexafluoropylene (HFP). A carboxyl-terminated liquid fluoroelastomer (t-CTLF) with controllable molar mass and end-group content was first prepared from a poly(VDF-ter-TFE-ter-HFP) terpolymer using a unique oxidative degradation method. Subsequently, an efficient “one-step” reduction of the carboxyl groups (COOH) in t-CTLF into hydroxyl groups (OH) was achieved via the functional-group conversion method using lithium aluminium hydride (LiAlH4) as the reductant. Thus, t-HTLF with a controllable molar mass and end-group content and highly active end groups was synthesised. Owing to the efficient curing reaction between OH and isocyanate groups (NCO), the cured t-HTLF exhibits good surface properties, thermal properties, and chemical stability. The thermal decomposition temperature (Td) of the cured t-HTLF reaches 334 °C, and it exhibits hydrophobicity. The oxidative degradation, reduction, and curing reaction mechanisms were also determined. The effects of solvent dosage, reaction temperature, reaction time, and ratio of the reductant to the COOH content on the carboxyl conversion were also systematically investigated. An efficient reduction system comprising LiAlH4 can not only achieve an efficient conversion of the COOH groups in t-CTLF to OH groups but also the in situ hydrogenation and addition reactions of residual double bonds (C=C) groups in the chain, such that the thermal stability and terminal activity of the product are improved while maintaining a high fluorine content. Full article
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11 pages, 2095 KiB  
Article
The Effect of Various Fillers on the Properties of Methyl Vinyl Silicone Rubber
by Yun Chen, Kun Wang, Chong Zhang, Wei Yang, Bo Qiao and Li Yin
Polymers 2023, 15(6), 1584; https://doi.org/10.3390/polym15061584 - 22 Mar 2023
Cited by 1 | Viewed by 1928
Abstract
Silicone rubber (SIR) has been widely used in electrical insulation fields, and the introduction of new materials is very important for the performance improvement of SIR composites. In this work, four different fillers, including aluminium hydroxide (ATH), yimonite (YMT), boron nitride (BN) and [...] Read more.
Silicone rubber (SIR) has been widely used in electrical insulation fields, and the introduction of new materials is very important for the performance improvement of SIR composites. In this work, four different fillers, including aluminium hydroxide (ATH), yimonite (YMT), boron nitride (BN) and mica-filled SIR composites were prepared, and the vulcanization behavior, mechanical properties, insulation performance and hydrophobicity of the SIR composites were investigated and compared. Both BN- and mica-filled SIR composites showed excellent insulation performance, while the ATH-filled SIR composite exhibited the best mechanical properties with an elongation at break of 230% and a tensile strength of 2.9 MPa. The SIR/BN composite showed a breakdown strength of 29.2 kV/mm with a 5% failure rate. The addition of YMT deteriorated the insulation performance of SIR but improved the elongation at break and hydrophobicity, with an elongation at break increasing from 115% to 410% and the static contact angle improving from 109.8° to 115.6°. Full article
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15 pages, 13936 KiB  
Article
Phase Behavior of NR/PMMA Semi-IPNs and Development of Porous Structures
by Jacob John, Damir Klepac, Mia Kurek, Mario Ščetar, Kata Galić, Srećko Valić, Sabu Thomas and Anitha Pius
Polymers 2023, 15(6), 1353; https://doi.org/10.3390/polym15061353 - 08 Mar 2023
Viewed by 1624
Abstract
In this research, the porous polymer structures (IPN) were made from natural isoprene rubber (NR) and poly(methyl methacrylate) (PMMA). The effects of molecular weight and crosslink density of polyisoprene on the morphology and miscibility with PMMA were determined. Sequential semi-IPNs were prepared. Viscoelastic, [...] Read more.
In this research, the porous polymer structures (IPN) were made from natural isoprene rubber (NR) and poly(methyl methacrylate) (PMMA). The effects of molecular weight and crosslink density of polyisoprene on the morphology and miscibility with PMMA were determined. Sequential semi-IPNs were prepared. Viscoelastic, thermal and mechanical properties of semi-IPN were studied. The results showed that the key factor influencing the miscibility in semi-IPN was the crosslinking density of the natural rubber. The degree of compatibility was increased by doubling the crosslinking level. The degree of miscibility at two different compositions was compared by simulations of the electron spin resonance spectra. Compatibility of semi-IPNs was found to be more efficient when the PMMA content was less than 40 wt.%. A nanometer-sized morphology was obtained for a NR/PMMA ratio of 50/50. Highly crosslinked elastic semi-IPN followed the storage modulus of PMMA after the glass transition as a result of certain degree of phase mixing and interlocked structure. It was shown that the morphology of the porous polymer network could be easily controlled by the proper choice of concentration and composition of crosslinking agent. A dual phase morphology resulted from the higher concentration and the lower crosslinking level. This was used for developing porous structures from the elastic semi-IPN. The mechanical performance was correlated with morphology, and the thermal stability was comparable with respect to pure NR. Investigated materials might be interesting for use as potential carriers of bioactive molecules aimed for innovative applications such as in food packaging. Full article
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15 pages, 3923 KiB  
Article
Temperature Effects on the Crystalline Structure of iPP Containing Different Solvent-Treated TMB-5 Nucleating Agents
by Baojing Luo, Sheng Xu, Jing Yang, Qing Zhang, Jing Yu, Lihua Liu and Xiangjun Meng
Polymers 2023, 15(3), 514; https://doi.org/10.3390/polym15030514 - 18 Jan 2023
Cited by 1 | Viewed by 1289
Abstract
TMB-5 nucleating agent (NA) treated by different solvents were used as the β-NA of iPP. The effects of temperature on the crystalline structure of different iPP/TMB-5, as well as the crystallization and melting behaviors were investigated. It was found that strong polar [...] Read more.
TMB-5 nucleating agent (NA) treated by different solvents were used as the β-NA of iPP. The effects of temperature on the crystalline structure of different iPP/TMB-5, as well as the crystallization and melting behaviors were investigated. It was found that strong polar solvent treated TMB-5 (TMB-5DMSO and TMB-5DMF) could induce more β-crystal at high Tc = 140 °C than the other TMB-5 NAs, while the β-crystal inducing efficiency of untreated TMB-5 (TMB-5UT) and non-polar solvent treated TMB-5 (TMB-5LP) is seriously reduced at high Tc = 140 °C. TMB-5DMSO can induce a high and stable content of β-crystal with Kβ = 83–94% within Tc = 90–140 °C, and TMB-5ODCB can induce a high content of β-crystal with Kβ > 91.3% within Tc = 90–130 °C. TMB-5DMF is the most temperature-sensitive one, but can induce a high fraction of β-crystal with Kβ > 92% both at low Tc = 90 °C and high Tc = 140 °C. High temperature pre-crystallization at Tpc = 150 °C tremendously reduces the β-crystal inducing efficiency of all TMB-5 NAs. TMB-5UT and TMB-5LP exhibit higher nucleating efficiency than TMB-5DMSO, TMB-5DMF and TMB-5ODCB. During the non-isothermal crystallization process, TMB-5UT induced β-crystal possesses higher structural perfection and stability, while TMB-5LP is more likely to induce α-crystal with considerable quantity and stability. The structural perfection and stability of TMB-5 induced β-crystal can be enhanced with appropriate increasing of Tc. Full article
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2022

Jump to: 2024, 2023

11 pages, 4562 KiB  
Article
Improving Mechanical, Electrical and Thermal Properties of Fluororubber by Constructing Interconnected Carbon Nanotube Networks with Chemical Bonds and F–H Polar Interactions
by Yurou Chen, Yadong Wu, Jun Li, Xuqiang Peng, Shun Wang and Huile Jin
Polymers 2022, 14(22), 4989; https://doi.org/10.3390/polym14224989 - 17 Nov 2022
Cited by 4 | Viewed by 1271
Abstract
To improve the properties of fluororubber (FKM), aminated carbon nanotubes (CNTs-NH2) and acidified carbon nanotubes (CNTs-COOH) were introduced to modulate the interfacial interactions in FKM composites. The effects of chemical binding and F–H polar interactions between CNTs-NH2, CNTs-COOH, and [...] Read more.
To improve the properties of fluororubber (FKM), aminated carbon nanotubes (CNTs-NH2) and acidified carbon nanotubes (CNTs-COOH) were introduced to modulate the interfacial interactions in FKM composites. The effects of chemical binding and F–H polar interactions between CNTs-NH2, CNTs-COOH, and FKM on the mechanical, electrical, thermal, and wear properties of the FKM composites were systematically investigated. Compared to the pristine FKM, the tensile strength, modulus at 100% strain, hardness, thermal conductivity, carbon residue rate, and electrical conductivity of CNTs-NH2/CNTs-COOH/FKM were increased by 112.2%, 587.5%, 44.2%, 37.0%, 293.5%, and nine orders of magnitude, respectively. In addition, the wear volume of CNTs-NH2/CNTs-COOH/FKM was reduced by 29.9%. This method provides a new and effective way to develop and design high-performance fluororubber composites. Full article
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13 pages, 2451 KiB  
Article
The Influence of Syringic Acid and Erucic Acid on the Antioxidant Properties of Natural Rubber: Experimental and Molecular Simulation Investigations
by Shihao Chen, Xiujuan Wang, Xueting Wang, Wei Zheng, Shaojian He, Meng Song and Hongzhen Wang
Polymers 2022, 14(20), 4254; https://doi.org/10.3390/polym14204254 - 11 Oct 2022
Cited by 6 | Viewed by 1272
Abstract
In this work, the influence of syringic acid (SA) and erucic acid (EA) on the oxidation resistance of natural rubber (NR) was investigated by combining experimental and computational methods. The antioxidant activities of SA and EA were predicted by calculating the enthalpy of [...] Read more.
In this work, the influence of syringic acid (SA) and erucic acid (EA) on the oxidation resistance of natural rubber (NR) was investigated by combining experimental and computational methods. The antioxidant activities of SA and EA were predicted by calculating the enthalpy of bond dissociation (BDE), the anti-migration ability of antioxidants (AOs) in the rubber matrix by calculating the mean square displacement (MSD), and the effect of antioxidants on oxygen barrier properties of rubber materials by calculating the permeability coefficient (P). The predicted result is that EA has a better comprehensive performance than SA. The DPPH (2,2-diphenyl-1-picrylhydrazyl) test and mechanical properties test demonstrated the results predicted by the simulations. Both SA and EA can protect natural rubber, while EA has a better comprehensive effect. Full article
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21 pages, 5321 KiB  
Review
Research Progress on Two-Dimensional Layered MXene/Elastomer Nanocomposites
by Hailan Kang, Lishuo Han, Shule Chen, Shuao Xie, Mengjiang Li, Qinghong Fang and Shaojian He
Polymers 2022, 14(19), 4094; https://doi.org/10.3390/polym14194094 - 29 Sep 2022
Cited by 8 | Viewed by 3859
Abstract
Two-dimensional (2D) transition-metal carbon/nitrogen/carbon nitride (MXene) has extremely high conductivity and easily modifiable surface functional groups. Compared with graphene, another 2D layered material, MXene is easily dispersed in water owing to its hydrophilic groups. Its unique characteristics make MXene a valuable material. Nanocomposites [...] Read more.
Two-dimensional (2D) transition-metal carbon/nitrogen/carbon nitride (MXene) has extremely high conductivity and easily modifiable surface functional groups. Compared with graphene, another 2D layered material, MXene is easily dispersed in water owing to its hydrophilic groups. Its unique characteristics make MXene a valuable material. Nanocomposites can be endowed with functionality when MXene is compounded with an elastomer. Particularly in electromagnetic interference shielding and sensing, MXene exhibits extraordinary properties. We review various preparation methods, properties, and applications of MXene and MXene/elastomer nanocomposites and present a summary of the prospects for MXene/elastomer nanocomposites, which are in their initial stage of development and providing promising results. Full article
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13 pages, 3207 KiB  
Article
Performance Enhancement of Polymerized, Functionalized Solution Styrene–Butadiene Rubber Composites Using Oligomeric Resin towards Extremely Safe and Energy-Saving Tires
by Neng Ye, Zhenya Wu, Xiaohui Wu, Yonglai Lu and Liqun Zhang
Polymers 2022, 14(14), 2928; https://doi.org/10.3390/polym14142928 - 20 Jul 2022
Cited by 3 | Viewed by 2096
Abstract
Polymerized, functionalized solution styrene–butadiene rubber (F-SSBR) is a new type of polymerized styrene–butadiene rubber solution containing specific terminal groups, which can be used in treads for high performances. However, the wet skid resistance related to safety, the rolling resistance to energy consumption, and [...] Read more.
Polymerized, functionalized solution styrene–butadiene rubber (F-SSBR) is a new type of polymerized styrene–butadiene rubber solution containing specific terminal groups, which can be used in treads for high performances. However, the wet skid resistance related to safety, the rolling resistance to energy consumption, and the wear resistance to service life are often contradictory and form the performance “magic triangle”. In this work, oligomeric resins, including Coumarone resin, C9 resin, C5/C9 resin and a styrene-α-methyl styrene copolymer (SSC), were used as tire functional additives and selected to replace treated distillate aromatic extract (TDAE) to improve the performances of silica-filled F-SSBR composites. The C9 resin, C5/C9 resin and SSC could enhance the modulus at 300% and tensile strength of the F-SSBR composite. The four resins could improve the wet skid resistance and wear resistance of the composites. However, Coumarone resin caused poor silica dispersion in the F-SSBR matrix and eventually, the lower modulus, higher loss factor at 60 °C and the higher heat buildup in the composite were comparative to the composite with TDAE. Furthermore, the synergistic effect of the C5/C9 resin and SSC was found to improve the mechanical performance of the composites and it resulted in higher tensile strength and modulus, and a lower heat buildup, compared to the case when only TDAE was used. It is noted that the properties “magic triangle” was broken by the C5/C9 resin and SSC, and the C5/C910T15 increased the wet skid resistance by 21.7%, fuel-saving rate by 2.3%, and wear resistance by 8.3%, while S20T5 increased the wet skid resistance by 30.4%, fuel-saving rate by 7%, and wear resistance by 25% compared with CG. Full article
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13 pages, 5834 KiB  
Article
Effects of Mechanical Stress on Insulation Structure and Performance of HV Cable
by Jingang Su, Liqiang Wei, Jingquan Zheng, Jiahao Liu, Peng Zhang, Xianhai Pang and Yunqi Xing
Polymers 2022, 14(14), 2927; https://doi.org/10.3390/polym14142927 - 20 Jul 2022
Cited by 3 | Viewed by 1955
Abstract
Mechanical stresses generated during manufacturing and laying process of high voltage cables can result in degradation of insulation properties, affecting the stable operation of the transmission system. Traditional test methods for testing the effect of mechanical stress on the insulation properties of polyethylene [...] Read more.
Mechanical stresses generated during manufacturing and laying process of high voltage cables can result in degradation of insulation properties, affecting the stable operation of the transmission system. Traditional test methods for testing the effect of mechanical stress on the insulation properties of polyethylene still have some shortcomings to be explored and it is able to explain the changes of the insulation properties of polyethylene under mechanical stress from a microscopic perspective. In order to further study the effect of stress on the insulation properties of polyethylene, microstructural changes, the breakdown field strength, conductivity and charge distribution of polyethylene at different elongation rates are investigated by a combination of experimental and molecular dynamics simulations. The results show that the increase in stress leads to a decrease in crystallinity and microcrystalline size of the material decrease. The untwisting and orientation of the polyethylene molecular chains during the stretching process can create cavities, resulting in an uneven sample distribution and thickness reduction, leading to a reduction in the breakdown field strength. Meanwhile, some crystal regions are transformed into amorphous regions. The loose amorphous regions facilitate the directional migration of carriers, resulting in the increase of conductivity. When the elongation ratio is smaller, the distance between the molecular chains increases and the trap depth of the specimen becomes shallower. This facilitates the migration of ions and electrons and increases the rate of decay of the surface potential. When the stretch is further increased, new traps are created by broken molecular chains to limit the movement of charges, decreasing the decay rate of the surface potential and reducing the insulation properties of the polyethylene. Meanwhile, the molecular dynamics model of semi-crystalline polyethylene was developed to observe the microstructure and energy changes during the stretching process. The conclusions in terms of tensile tests were verified from a microscopic perspective. Full article
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15 pages, 8245 KiB  
Article
Fabrication of Highly Conductive Silver-Coated Aluminum Microspheres Based on Poly(catechol/polyamine) Surface Modification
by Mingzheng Hao, Lei Li, Xiaoming Shao, Ming Tian, Hua Zou, Liqun Zhang and Wencai Wang
Polymers 2022, 14(13), 2727; https://doi.org/10.3390/polym14132727 - 03 Jul 2022
Cited by 6 | Viewed by 2205
Abstract
A novel and cost-effective method for the fabrication of highly conductive Al/Ag core-shell structured microspheres was proposed and investigated. The oxidative co-deposition of catechol and polyamine was firstly performed to modify the surface of the aluminum microsphere. Then, a two-step electroless plating was [...] Read more.
A novel and cost-effective method for the fabrication of highly conductive Al/Ag core-shell structured microspheres was proposed and investigated. The oxidative co-deposition of catechol and polyamine was firstly performed to modify the surface of the aluminum microsphere. Then, a two-step electroless plating was conducted to fabricate the Al/Ag microspheres. During the first step of the electroless plating process, the surface of the aluminum microsphere was deposited with silver nanoparticle seeds using n-octylamine and ethylene glycol. Then, during the second step of the electroless plating process, silver particles grew evenly to form a compact silver shell on the surface of aluminum via a silver mirror reaction. According to the scanning electron microscope and energy dispersive X-ray results, a compact and continuous silver layer was successfully generated on the surface of the aluminum. The valence of the sliver on the surface of the aluminum was confirmed to be zero, based on the X-ray photoelectron spectrometer and X-ray diffractometer analyses. As a result, the as-prepared Al/Ag microspheres exhibited a high conductivity of 10,000 S/cm. The Al/Ag/MVQ composite demonstrated low electrical resistivity of 0.0039 Ω·cm and great electromagnetic interference shielding effectiveness at more than 70 dB against the X-band, and this result suggests that the as-prepared composite is a promising conductive and electromagnetic shielding material. Full article
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12 pages, 4665 KiB  
Article
Polymer Composite with Enhanced Thermal Conductivity and Insulation Properties through Aligned Al2O3 Fiber
by Sijiao Wang, Mengmeng Chen and Kaiming Cao
Polymers 2022, 14(12), 2374; https://doi.org/10.3390/polym14122374 - 12 Jun 2022
Cited by 6 | Viewed by 1554
Abstract
Thermoplastic polyolefins, such as polyethylene (PE), are traditionally one of the most widely used polymer classes with applications in the electric industry, and their nanocomposites have caught the interest of researchers. The linear filler is shown to be beneficial in decreasing the charge [...] Read more.
Thermoplastic polyolefins, such as polyethylene (PE), are traditionally one of the most widely used polymer classes with applications in the electric industry, and their nanocomposites have caught the interest of researchers. The linear filler is shown to be beneficial in decreasing the charge injection and hindering the formation of charge packs. So, we demonstrate a novel composite with excellent properties. The low-density polyethylene (LDPE) composite with aligned aluminum oxide (Al2O3) fiber has been prepared in electric field conditions. The direction of the Al2O3 fiber was parallel to the thickness direction of the LDPE composite. The breakdown strength of the Al2O3/LDPE composite with 0.2% aligned Al2O3 fiber was 498 kV/mm, which is higher than other fillers induced. The aligned Al2O3 fiber has effect on preventing accumulation of space charge and reducing the amount of free electron in the material. In addition, the thermal conductivity of the LDPE composite (0.22 W/m·K) was increased to 0.85 W/m·K when doped with 0.5 wt% aligned Al2O3 fiber. The present structure provides a new possibility for mass new nanocomposites with excellent microstructures and remarkable functionality. Full article
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20 pages, 11615 KiB  
Article
Heat Build-Up and Rolling Resistance Analysis of a Solid Tire: Experimental Observation and Numerical Simulation with Thermo-Mechanical Coupling Method
by Hong He, Jinming Liu, Yaru Zhang, Xue Han, William V. Mars, Liqun Zhang and Fanzhu Li
Polymers 2022, 14(11), 2210; https://doi.org/10.3390/polym14112210 - 30 May 2022
Cited by 8 | Viewed by 2357
Abstract
The hysteresis of rubber materials due to deformation and viscoelasticity is the main reason for the heat build-up (HBU) and rolling resistance (RR) of the rolling tire. It is important to realize the high precision prediction of HBU and RR of tire for [...] Read more.
The hysteresis of rubber materials due to deformation and viscoelasticity is the main reason for the heat build-up (HBU) and rolling resistance (RR) of the rolling tire. It is important to realize the high precision prediction of HBU and RR of tire for the optimal design of high-performance fuel-saving tire. In this work, a thermo-mechanical coupling method based on Endurica and Abaqus co-simulation was used to predict the steady-state temperature distribution and RR of three finite element models (Lagrangian–Eulerian model, Lagrangian model, and Plane Strain model) of the solid tires under different loads and rotating speeds. The simulation results were compared with the experimental results. The Kraus self-heating model was utilized in the thermo-mechanical coupling method, which realized the quantitative relationship between the dynamic loss modulus of rubber and the loading conditions (temperature, strain, and strain rate). Special attention was paid to the determination of the material parameters in the Kraus self-heating model. The comparison between simulation results and experimental results shows that the Lagrangian model had the highest prediction accuracy, and the average prediction errors of the steady-state surface temperature and RR under three loading conditions were 3.4% and 7.9%, respectively. The Lagrangian–Eulerian model came in the second with average errors of 9.7% and 11.1%, respectively. The Plane Strain model had the worst prediction accuracy, with the average errors of 21.4% and 44.6%, respectively. In terms of the simulation time, the Plane Strain model had the lowest cost, and the average calculation time was 1143 s. The Lagrangian–Eulerian model took the second place, with an average calculation time of 2621 s. The Lagrangian model had the highest computation cost, with an average time of 5597 s. The comparison between the simulation results and the experimental results verified the effectiveness of the thermo-mechanical coupling analysis method. The methods of three finite element models of the solid tires in this work can provide some reference for the optimization design of elastomeric components (Lagrangian model), pneumatic tires (Lagrangian–Eulerian model), and non-pneumatic tires (Plane Strain model). Full article
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16 pages, 6890 KiB  
Article
Effects of Ligands in Rare Earth Complex on Properties, Functions, and Intelligent Behaviors of Polyurea–Urethane Composites
by Lu Zhou, Hongwei Yang, Zhen Zhang, Yue Liu, Jayantha Epaarachchi, Zhenggang Fang, Liang Fang, Chunhua Lu and Zhongzi Xu
Polymers 2022, 14(10), 2098; https://doi.org/10.3390/polym14102098 - 21 May 2022
Cited by 2 | Viewed by 1533
Abstract
There is a need to create next-generation polymer composites having high property, unique function, and intelligent behaviors, such as shape memory effect (SME) and self-healing (SH) capability. Rare earth complexes can provide luminescence for polymers, and their dispersion is highly affected by ligand [...] Read more.
There is a need to create next-generation polymer composites having high property, unique function, and intelligent behaviors, such as shape memory effect (SME) and self-healing (SH) capability. Rare earth complexes can provide luminescence for polymers, and their dispersion is highly affected by ligand structures. Here, we created three different REOCs with different ligands before studying the effects of ligands on REOC dispersion in polyurea–urethane (PUU) with disulfide bonds in main chains. In addition, the effects of different REOCs on mechanical properties, luminescent functions, and intelligent behaviors of PUU composites were studied. The results showed that REOC I (Sm(TTA)3phen: TTA, thenoyltrifluoroacetone; phen, 1,10-phenanthroline) has incompatible ligands with the PUU matrix. REOC I and REOC III (Sm(BUBA)3phen: BUBA, 4-benzylurea-benzoic acid) with amine and urea groups facilitate their dispersion. It was REOC III that helped the maintenance of mechanical properties of PUU composites due to the good dispersion and the needle-like morphologies. Due to more organic ligands of REOC III, the fluorescence intensity of composite materials is reduced. The shape recovery ratio of the composite was not as good as that of pure PUU when a large amount of fillers was added. Besides, REOC I reduced the self-healing efficiency of PUU composites due to poor dispersion, and the other two REOCs increased the self-healing efficiency. The results showed that ligands in REOCs are important for their dispersion in the PUU matrix. The poor dispersion of REOC I is unbeneficial for mechanical properties and intelligent behavior. The high miscibility of REOC II (Sm(PABA)3phen: PABA, 4-aminobenzoic acid) decreases mechanical properties as well but ensures the good shape recovery ratio and self-healing efficiency. The mediate miscibility and needle-like morphology of REOC III are good for mechanical properties. The shape recovery ratio, however, was decreased. Full article
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14 pages, 2716 KiB  
Article
Research on the Influence of Extremely Cold Environment on the Performance of Silicone Rubber and Fluorinated Silicone Rubber
by Shenghui Wang, Mengchao Hou, Kang Ma, Zhiwei Li, Hui Geng, Wenwen Zhang and Nan Li
Polymers 2022, 14(9), 1898; https://doi.org/10.3390/polym14091898 - 06 May 2022
Cited by 5 | Viewed by 2114
Abstract
In order to study the performance variation characteristics of silicone rubber and fluorinated silicone rubber at extremely cold temperatures, two type samples were frozen for 0, 150, 300, 450, 600, 750, 900 and 1050 h in a low-temperature test chamber with a constant [...] Read more.
In order to study the performance variation characteristics of silicone rubber and fluorinated silicone rubber at extremely cold temperatures, two type samples were frozen for 0, 150, 300, 450, 600, 750, 900 and 1050 h in a low-temperature test chamber with a constant temperature of −50 °C. After the samples reached a certain freezing time, they were taken out and placed at room temperature for 2 h, then the breakdown voltage, mechanical tensile properties, and hardness and surface morphology were measured, and the mechanism was analyzed. The breakdown voltage, maximum tensile force, and tensile strength of the two type samples increased with freezing time. The elongation at break decreased with freezing time, but the hardness of the two materials changed little. Microcracks appeared on the surface of the samples at about 300 h and some tiny pore and holes appeared at 750 h. The length and depth of the microcracks gradually developed with freezing time. The comparative test results of the two materials showed that the performance of fluorinated silicone rubber was better than that of silicone rubber, which indicates that fluorinated silicone rubber is more stable for some applications in extremely cold environments. Full article
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19 pages, 7456 KiB  
Article
Mechanism and Influence Factors of Abrasion Resistance of High-Flow Grade SEBS/PP Blended Thermoplastic Elastomer
by Shuwen Liu, Jun Qiu, Lili Han, Xueyan Ma and Wenquan Chen
Polymers 2022, 14(9), 1795; https://doi.org/10.3390/polym14091795 - 28 Apr 2022
Cited by 5 | Viewed by 2281
Abstract
Hydrogenated styrene-butadiene-styrene block copolymer (SEBS)/polypropylene (PP) blended thermoplastic elastomer (TPE) is suitable for preparing the automotive interiors because of its excellent elasticity, softness, weather resistance, low odor, low VOC and other environmental-friendly properties. The skin of the automobile instrument panel is an appearance [...] Read more.
Hydrogenated styrene-butadiene-styrene block copolymer (SEBS)/polypropylene (PP) blended thermoplastic elastomer (TPE) is suitable for preparing the automotive interiors because of its excellent elasticity, softness, weather resistance, low odor, low VOC and other environmental-friendly properties. The skin of the automobile instrument panel is an appearance part, which requires excellent friction loss resistance of surface. In this paper, the high-flow SEBS/PP blended thermoplastic elastomer (TPE) suitable for the preparation of injection molding skins for automobile instrument panel was studied. By comparing the Taber abrasion and cross-scratch properties, the effects of SEBS’s molecular weight, styrene content in the molecule, molecular structure and types of lubricating agents on the friction loss properties of the material were investigated. The results show that under the same SEBS molecular structure, the higher the molecular weight within a certain range, the better the wear resistance of high-flow SEBS/PP type TPE, but the ultra-high molecular weight exhibits lower wear resistance than high molecular weight; The high-flow SEBS/PP blended TPE prepared by medium styrene content SEBS has better abrasion resistance; TPE prepared by star SEBS is better than linear SEBS; Adding silane-based lubricating agents is beneficial to improve the friction loss resistance of the material, especially combined use of high and low molecular weight silicone. Full article
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13 pages, 6686 KiB  
Article
Aqueous Strippable Polymer Coating for Highly Efficient Primary Radioactive Uranium Decontamination with Versatility on Diversified Surface
by Yang Xue, Wuxinchen Yang, Renliang Yue and Yunfa Chen
Polymers 2022, 14(9), 1656; https://doi.org/10.3390/polym14091656 - 20 Apr 2022
Cited by 6 | Viewed by 1949
Abstract
The decontamination of radioactive materials on the surfaces of nuclear facilities has generated large quantities of waste from the rapid development of the nuclear industry, posing a potential threat globally. Strippable coating has been employed for some time to remove radioactive contamination due [...] Read more.
The decontamination of radioactive materials on the surfaces of nuclear facilities has generated large quantities of waste from the rapid development of the nuclear industry, posing a potential threat globally. Strippable coating has been employed for some time to remove radioactive contamination due to its high performance and removability, flexibility, and compatibility with various substrates. Herein, an aqueous strippable coating based on an adsorbent/polyvinyl alcohol (PVA) polymer was developed to remove radioactive uranium from stainless-steel surfaces that showed greater decontamination than that of DeconGel, with an efficiency of 87.2% for 5 g/L uranium and 95.5% for 22.5 g/L uranium, along with a high repeatability and better mechanical properties. Furthermore, the prepared coating was versatile and could be applied to a range of substrate surfaces (lacquered, aluminum, glass, plastic, and ceramic), with outstanding performance ranging from 79.2 to 95.4% for 1 g/L uranium. The prepared coating could also be applied through brushing or spraying to horizontal or vertical substrates. The exceptional performance could be due to the synergistic effect of the introduction of ethylene diamine tetra-acetic acid disodium salt (EDTA-2Na) as a chelating agent and the nano-adsorbent CaCO3/TiO2. Full article
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13 pages, 3345 KiB  
Article
Study on Surface Discharge Characteristics of GO-Doped Epoxy Resin–LN2 Composite Insulation
by Yunqi Xing, Yuanyuan Chen, Ruiyi Yuan, Zhuoran Yang, Tianyi Yao, Jiehua Li, Wenbo Zhu and Xiaoxue Wang
Polymers 2022, 14(7), 1432; https://doi.org/10.3390/polym14071432 - 31 Mar 2022
Viewed by 1711
Abstract
Superconducting power lead equipment for epoxy insulation, such as high-temperature superconducting DC power or liquefied natural gas energy pipelines, as well as high-temperature superconducting cables, has long been used in extreme environments, from liquid nitrogen temperatures to normal temperatures. It is easy to [...] Read more.
Superconducting power lead equipment for epoxy insulation, such as high-temperature superconducting DC power or liquefied natural gas energy pipelines, as well as high-temperature superconducting cables, has long been used in extreme environments, from liquid nitrogen temperatures to normal temperatures. It is easy to induce surface discharge and flashover under the action of strong electric field, which accelerates the insulation failure of current leads. In this paper, two-dimensional nano-material GO was used to control the electrical properties of epoxy resins. The DC surface discharge and flashover characteristics of the prepared epoxy resin–GO composite insulation materials were tested at room temperature with liquid nitrogen. The surface discharge mechanism of the epoxy resin–GO composite insulation materials was analyzed. The experimental results show that the insulation properties of epoxy composites doped with GO changed. Among them, the surface flashover voltage of 0.05 wt% material is the best, which can inhibit the discharge phenomenon and improve its insulation properties in extreme environments, from room temperature to liquid nitrogen temperature. It is found that the development process of surface discharge of composite insulating materials under liquid nitrogen is quite different from that under room temperature. Before critical flashover, the repetition rate and amplitude of surface discharge remain at a low level until critical flashover. Furthermore, the voltage of the first flashover is significantly higher than that of the subsequent flashover under the action of the desorption gas on the surface of the composite insulating material and the gasification layer produced by the discharge. Given that the surface flashover voltage of 0.05 wt% epoxy composite is the best, the research and analysis of 0.05 wt% composite is emphasized. In the future design of superconducting power lead insulation, the modification method of adding GO to epoxy resin can be considered in order to improve its insulation performance. Full article
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11 pages, 6663 KiB  
Article
Study on Thermal-Oxidative Aging Properties of Ethylene-Propylene-Diene Monomer Composites Filled with Silica and Carbon Nanotubes
by Xiaoming Zhang, Jian Li, Zilong Chen, Ce Pang, Shaojian He and Jun Lin
Polymers 2022, 14(6), 1205; https://doi.org/10.3390/polym14061205 - 17 Mar 2022
Cited by 12 | Viewed by 2022
Abstract
In this work, a small amount of carbon nanotubes (CNTs) was used to partially replace the silica in ethylene-propylene-diene monomer (EPDM) to prepare EPDM composites via mechanical blending. The mechanical properties, thermal-oxidative aging properties and thermal stability of the composites were systematically investigated. [...] Read more.
In this work, a small amount of carbon nanotubes (CNTs) was used to partially replace the silica in ethylene-propylene-diene monomer (EPDM) to prepare EPDM composites via mechanical blending. The mechanical properties, thermal-oxidative aging properties and thermal stability of the composites were systematically investigated. The results showed that with the increase of CNTs content, the Shore A hardness and stress at 100% strain of the composites increased, while the elongation at break decreased. With the aging time increasing, the aging coefficient and elongation at break of composites decreased while hardness increased due to the raise of crosslinking density. In addition, evidences were found to demonstrate the improved aging resistance by adding CNTs in the EPDM composites, including the less change in Shore A hardness, the smaller change ratio of elongation at break and the lower aging coefficient. When the content of CNTs reached 10 phr, the aging coefficient of the EPDM composite aged for 168 h was nearly twice that of the composite without CNTs, and the thermal stability of the EPDM composite with CNTs was improved as demonstrated by thermal analysis. Full article
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