Plastics II

A special issue of Polymers (ISSN 2073-4360). This special issue belongs to the section "Polymer Applications".

Deadline for manuscript submissions: closed (20 January 2024) | Viewed by 11956

Special Issue Editors

Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Lodz, Poland
Interests: polymers; nanocomposites; polymer blends; materials science; shape memory effect; severe plastic deformation; lattice structure; 3D printing
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Special Issue Information

Dear Colleagues,

Plastic deformation and fracture processes, both in the laboratory conditions and in industrial practice, are largely dealt with on a phenomenological level, and are often separate for different polymers, blends, and composites, and less often from a mechanistic perspective. Thus, it is integral to understand the mechanisms governing the deformation and fracture resistance of polymers. Simultaneously, fundamental developments in polymer materials science and polymer physics now make it possible to consider plastic deformation and fracture at an appropriate molecular and morphological level. Moreover, insight gained from computational simulations and mechanistic modelling is also broadening this perspective. This Special Issue aims to present a coherent illustration of the plastic deformation and fracture of polymer materials of different structures and architectures. I invite research articles, communication articles, or review articles covering various aspects of the plastic deformation and fracture of polymer materials.

Dr. Ian Wyman
Dr. Yuri Voznyak
Guest Editors

Manuscript Submission Information

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Keywords

  • plasticity of glassy/semicrystalline polymers
  • mechanisms of plastic deformation
  • deformation instabilities
  • crazing in homo- and heteropolymers, blends, composites
  • cracks and fracture
  • craze initiation
  • cavitation
  • toughening of polymers
  • new methods of plastic deformation
  • deformation-induced structure and phase transformation
  • simulation, micromechanics-based modeling

Published Papers (9 papers)

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Research

13 pages, 3312 KiB  
Article
The Initial Stage of Climatic Aging of Basalt-Reinforced and Glass-Reinforced Plastics in Extremely Cold Climates: Regularities
by Anatoly K. Kychkin, Anna A. Gavrilieva, Aisen A. Kychkin, Irina G. Lukachevskaya and Mikhail P. Lebedev
Polymers 2024, 16(7), 866; https://doi.org/10.3390/polym16070866 - 22 Mar 2024
Viewed by 301
Abstract
Detailed analyses of the reasons for changes in the mechanical parameters of fiberglass exposed to different climatic zones have been made available in the literature; however, such detailed studies of basalt plastic do not yet exist. It is possible to make reasonable conclusions [...] Read more.
Detailed analyses of the reasons for changes in the mechanical parameters of fiberglass exposed to different climatic zones have been made available in the literature; however, such detailed studies of basalt plastic do not yet exist. It is possible to make reasonable conclusions on the climatic resistance of reinforced plastics by monitoring the deformation–strength characteristics in combination with fractographic and DMA analyses of the solar- and shadow-exposed parts of the plastics; additionally, one can conduct analyses of the IR spectrum and the moisture sorbtion kinetics. As a starting point for the climatic aging of polymer composite materials, it is necessary to accept the time of exposure in which the maximum values of the elastic strength properties of polymeric materials are achieved. Based on the results of the DMA analysis, it was found that, unlike basalt-reinforced plastics (where the material is post-cured exclusively at the initial stage of the exposure), in glass-reinforced plastic, a process of destruction occurs. The formation of internal stresses in the material and their growth were determined through observing the duration of climatic exposure. The formation of closed porosity, depending on the duration of exposure, can be assessed using the values of the increase in the average moisture content. A set of experimental studies has established that glass-reinforced plastics are subject to greater destruction under the influence of a very cold climate than the basalt-reinforced plastic. Full article
(This article belongs to the Special Issue Plastics II)
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20 pages, 3094 KiB  
Article
Characterization of Nanoprecipitated PET Nanoplastics by 1H NMR and Impact of Residual Ionic Surfactant on Viability of Human Primary Mononuclear Cells and Hemolysis of Erythrocytes
by Milica Djapovic, Danijela Apostolovic, Vojislava Postic, Tamara Lujic, Vesna Jovanovic, Dragana Stanic-Vucinic, Marianne van Hage, Veselin Maslak and Tanja Cirkovic Velickovic
Polymers 2023, 15(24), 4703; https://doi.org/10.3390/polym15244703 - 13 Dec 2023
Viewed by 819
Abstract
Manufactured nanoplastic particles (NPs) are indispensable for in vitro and in vivo testing and a health risk assessment of this emerging environmental contaminant is needed. The high surface area and inherent hydrophobicity of plastic materials makes the production of NPs devoid of any [...] Read more.
Manufactured nanoplastic particles (NPs) are indispensable for in vitro and in vivo testing and a health risk assessment of this emerging environmental contaminant is needed. The high surface area and inherent hydrophobicity of plastic materials makes the production of NPs devoid of any contaminants very challenging. In this study, we produced nanoprecipitated polyethylene terephthalate (PET) NPs (300 nm hydrodynamic diameter) with an overall yield of 0.76%. The presence of the ionic surfactant sodium dodecyl sulfate (SDS) was characterized by 1H NMR, where the relative ratio of NP/surfactant was monitored on the basis of the chemical shifts characteristic of PET and SDS. For a wide range of surfactant/NP ratios (17:100 to 1.2:100), the measured zeta potential changed from −42.10 to −34.93 mV, but with an NP concentration up to 100 μg/mL, no clear differences were observed in the cellular assays performed in protein-rich media on primary human cells. The remaining impurities contributed to the outcome of the biological assays applied in protein-free buffers, such as human red blood cell hemolysis. The presence of SDS increased the NP-induced hemolysis by 1.5% in protein-rich buffer and by 7.5% in protein-free buffer. As the size, shape, zeta potential, and contaminants of NPs may all be relevant parameters for the biological effects of NPs, the relative quantification of impurities exemplified in our work by the application of 1H NMR for PET NPs and the ionic surfactant SDS could be a valuable auxiliary method in the quality control of manufactured NPs. Full article
(This article belongs to the Special Issue Plastics II)
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13 pages, 7877 KiB  
Article
Integrity Assessment of High-Performance PVC Pipes for Thermal Wells
by Sayyad Zahid Qamar, Tasneem Pervez and Farooq Al-Jahwari
Polymers 2023, 15(17), 3593; https://doi.org/10.3390/polym15173593 - 29 Aug 2023
Viewed by 1012
Abstract
In wells with high-viscosity crude oil, steam injection is used to improve the fluidity of the heavy oil. Screens made of steel are employed for sand control, with corrosion being a serious problem. Non-metallic pipe materials, such as novel high-strength PVC, are therefore [...] Read more.
In wells with high-viscosity crude oil, steam injection is used to improve the fluidity of the heavy oil. Screens made of steel are employed for sand control, with corrosion being a serious problem. Non-metallic pipe materials, such as novel high-strength PVC, are therefore being tried out. This paper presents the results of an integrity assessment of large-diameter hard PVC pipes under compressive loading. Plain, built-up, and slotted pipes were subjected to a 3-month aging process in saline water. Strain gauge sets were used for dynamic testing of longitudinal and transverse deformations. Values of fracture strength, total deformation, and anisotropy (Poisson’s ratio) were extracted from the stress–strain graphs and analyzed. Upon aging in saline water, the stiffness of all pipes increased and was the highest for slotted pipes. Maximum stress after soaking was reduced by 11–12%. The ductility was the highest for plain pipes and the lowest for built-up pipes. Poisson’s ratio remained almost constant for all pipes and aging conditions. The good news for field applications is that overall, aging had only a minor impact on the major compressive properties. The main conclusion was that corrosion-prone steel pipes and sand screens can be successfully replaced by corrosion-free high-strength PVC pipes and screens for water transport applications in thermal wells. This work provides a scientific basis for the structural integrity assessment of this new PVC and helps field engineers in the proper pre-deployment selection of pipes for target oilfields. Full article
(This article belongs to the Special Issue Plastics II)
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15 pages, 4675 KiB  
Article
A Coupled Electro-Mechanical Homogenization-Based Model for PVDF-Based Piezo-Composites Considering α → β Phase Transition and Interfacial Damage
by Fateh Enouar Mamache, Amar Mesbah, Fahmi Zaïri and Iurii Vozniak
Polymers 2023, 15(14), 2994; https://doi.org/10.3390/polym15142994 - 10 Jul 2023
Viewed by 771
Abstract
Polyvinylidene fluoride or polyvinylidene difluoride (PVDF) is a piezoelectric semi-crystalline polymer whose electro-mechanical properties may be modulated via strain-induced α → β phase transition and the incorporation of polarized inorganic particles. The present work focuses on the constitutive representation of PVDF-based piezo-composites developed [...] Read more.
Polyvinylidene fluoride or polyvinylidene difluoride (PVDF) is a piezoelectric semi-crystalline polymer whose electro-mechanical properties may be modulated via strain-induced α → β phase transition and the incorporation of polarized inorganic particles. The present work focuses on the constitutive representation of PVDF-based piezo-composites developed within the continuum-based micromechanical framework and considering the combined effects of particle reinforcement, α → β phase transition, and debonding along the interface between the PVDF matrix and the particles under increasing deformation. The micromechanics-based model is applied to available experimental data of PVDF filled with various concentrations of barium titanate (BaTiO3) particles. After its identification and predictability verification, the model is used to provide a better understanding of the separate and synergistic effects of BaTiO3 particle reinforcement and the micromechanical deformation processes on the electro-mechanical properties of PVDF-based piezo-composites. Full article
(This article belongs to the Special Issue Plastics II)
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15 pages, 3697 KiB  
Article
Blending of the Thermodynamically Incompatible Polyvinyl Chloride and High-Pressure Polyethylene Polymers Using a Supercritical Fluid Anti-Solvent Method (SEDS) Dispersion Process
by Vener F. Khairutdinov, Ilnar Sh. Khabriev, Farid M. Gumerov, Rafail M. Khuzakhanov, Ruslan M. Garipov, Lenar Yu. Yarullin and Ilmutdin M. Abdulagatov
Polymers 2023, 15(9), 1986; https://doi.org/10.3390/polym15091986 - 22 Apr 2023
Viewed by 1249
Abstract
The experimental solubility data of polyvinyl chloride (PVC) and high-pressure polyethylene (HPPE) in organic solvents (toluene, dichloromethane, and chloroform) at temperatures ranging from 308.15 to 373.15 K at atmospheric pressure are reported in the present paper. The solubility of the polymers (PVC and [...] Read more.
The experimental solubility data of polyvinyl chloride (PVC) and high-pressure polyethylene (HPPE) in organic solvents (toluene, dichloromethane, and chloroform) at temperatures ranging from 308.15 to 373.15 K at atmospheric pressure are reported in the present paper. The solubility of the polymers (PVC and HPPE) in organic solvents (toluene, dichloromethane, and chloroform) was studied at temperatures between 298 and 373 K. The supercritical SEDS dispersion of PVC and HPPE polymer blends at pressures between 8.0 and 25 MPa and at temperatures from 313 to 333 K are reported in the present work. The kinetics of crystallization and phase transformation in polymer blends obtained by blending in a melt, and using the supercritical SEDS method, have been studied. The effect of the HPPE/PVC ratio on the thermal and mechanical characteristics of the polymer blends has been studied. For all studied polymer blends and pure polymers obtained using the SEDS method, the heat of fusion ΔfusH exceeds the values obtained by blending in the melt by 1.5 to 5) times. The heat of fusion of the obtained polymer blends is higher than the additive value; therefore, the degree of crystallinity is higher, and this effect persists after heat treatment. The relative elongation decreases for all polymer blends, but their tensile strength increases significantly. Full article
(This article belongs to the Special Issue Plastics II)
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19 pages, 5082 KiB  
Article
Influence of Injection Molding Parameters on the Peel Strength between Plasma-Treated Fluoropolymer Films and Polycarbonate
by Martin Hubmann, Jonas Groten, Martin Pletz, Thomas Grießer, Kateřina Plevová, Wolfgang Nemitz and Barbara Stadlober
Polymers 2023, 15(6), 1568; https://doi.org/10.3390/polym15061568 - 21 Mar 2023
Cited by 1 | Viewed by 1608
Abstract
Light guiding is used to direct light from an emitting source to a different location. It is frequently realized through a clad–core structure with a difference in the refractive index of the materials. This paper explores the possibility of combining a fluoropolymer (THV) [...] Read more.
Light guiding is used to direct light from an emitting source to a different location. It is frequently realized through a clad–core structure with a difference in the refractive index of the materials. This paper explores the possibility of combining a fluoropolymer (THV) film of low refractive index, serving as a cladding layer, with a polycarbonate (PC) core, via injection molding. Pristine THV lacks adherence to the PC. However, when treated with O2 plasma prior to overmolding, bonding can be established that was quantified in peel tests. The effect of this surface treatment was further investigated by adjusting the plasma treatment duration and time to overmolding. Furthermore, parameter studies comprising the four molding parameters, namely packing pressure, injection speed, melt temperature, and mold temperature, were performed. Numerical injection molding simulations assessed the prevailing temperatures at the PC–THV boundary. Consequently, the temperature–time integral could be calculated and linked with the measured peel strengths by fitting a proportionality constant. While the plasma treatment duration showed minor influence, the activation diminished with time, halving the measured peel loads within 24 h. The adhesion was experimentally found to increase with a lower packing pressure, faster injection speed, and higher melt and mold temperature. Those same molding relations influencing the peel loads were also found with the temperature–time integral when scaled by the proportionality constant in the simulations (R2=85%). Apparently, adhesion is added by molding settings which promote higher interface temperatures that prevail for longer. Hereby, the faster injection speed increases the melt temperature through shear heating. A higher packing pressure, in contrast, presumably increases the heat transfer at the PC–THV interface, accelerating the cooling. The measured peel loads were 0.3–1.6 N/mm for plasma-treated samples and nearly zero for pristine THV. Full article
(This article belongs to the Special Issue Plastics II)
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19 pages, 9897 KiB  
Article
Elasto-Plastic Mechanical Modeling of Fused Deposition 3D Printing Materials
by Francesco Bandinelli, Lorenzo Peroni and Alberto Morena
Polymers 2023, 15(1), 234; https://doi.org/10.3390/polym15010234 - 02 Jan 2023
Cited by 11 | Viewed by 1853
Abstract
Fused deposition modeling (FDM) is one of the most common 3D printing technologies and is becoming a well-established production method. Short fiber-reinforced polymers represent a new class of printing materials that enhance the mechanical properties of final components, thus informing an interesting subject [...] Read more.
Fused deposition modeling (FDM) is one of the most common 3D printing technologies and is becoming a well-established production method. Short fiber-reinforced polymers represent a new class of printing materials that enhance the mechanical properties of final components, thus informing an interesting subject of analysis for this study. FDM-printed parts are characterized by a strong anisotropy, so their behavior should be analyzed accordingly. The authors proposed a modeling strategy based on a transversely isotropic behavior hypothesis, representing material behaviors associated with an elasticity matrix in relation to the elastic field and a combination of Hill’s yield criterion and Voce’s isotropic hardening law for the plastic field. Material properties of materials were experimentally identified through tensile tests on dog bone specimens printed with different orientations in space. The numerical model was then calibrated using the finite element software LS-DYNA and the optimization software LS-OPT. An agreement between numerical and experimental results showed the robustness of the modeling strategy proposed to describe the stress behaviors of printed materials until a maximum load is reached, while strain behaviors have yet to be correctly defined due to the difficulties associated with evaluating an equivalent deformation. Full article
(This article belongs to the Special Issue Plastics II)
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26 pages, 7618 KiB  
Article
Plastic Deformation of High Density Polyethylene with Extended-Chain Crystal Morphology
by Alina Vozniak and Zbigniew Bartczak
Polymers 2023, 15(1), 66; https://doi.org/10.3390/polym15010066 - 24 Dec 2022
Cited by 4 | Viewed by 2514
Abstract
Samples of polyethylene with extended-chain crystal morphology, obtained by crystallization under high pressure, were subjected to uniaxial compression to various strains. Accompanying structural changes were analyzed using scanning electron microscopy. At the true strain of e = 0.2–0.3 the microbuckling instability was observed [...] Read more.
Samples of polyethylene with extended-chain crystal morphology, obtained by crystallization under high pressure, were subjected to uniaxial compression to various strains. Accompanying structural changes were analyzed using scanning electron microscopy. At the true strain of e = 0.2–0.3 the microbuckling instability was observed in longitudinally loaded lamellae, resulting in the formation of angular kinks. This induced a rapid reorientation of the lamellae, facilitating their further deformation by crystallographic slip. Microbuckling instability was found to occur earlier than in samples with folded-chain crystal morphology (e = 0.3–0.4) due to a smaller ratio of the amorphous to crystalline layer thickness. SEM observations demonstrated that the microbuckling instability begins with small undulation in long lamellae. Sharp angular lamellar kinks develop from the initial undulation through intense plastic deformation by crystallographic slip along the chain direction. The same slip system was found to operate throughout the kink, including the tip region as well as both limbs. In contrast to thin folded-chain lamellae that often undergo fragmentation during deformation, the thick extended-chain lamellae deform stably by chain slip and retain their continuity up to high strains, e > 1.6. This stability of deformation is related to the large thickness of extended-chain lamellae. Full article
(This article belongs to the Special Issue Plastics II)
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12 pages, 4990 KiB  
Article
In Situ Measured Tooth Flank Wear of Plastic Gears under Spectrum Loading
by Christoph Herzog, Michael Wolf and Dietmar Drummer
Polymers 2022, 14(23), 5239; https://doi.org/10.3390/polym14235239 - 01 Dec 2022
Cited by 3 | Viewed by 1153
Abstract
The wear behaviour of PBT-steel gear sets under temporarily changed load has been investigated using an in situ gear test rig developed at the LKT. The in situ test method is based on analysing the timing differences between the index pulses of rotary [...] Read more.
The wear behaviour of PBT-steel gear sets under temporarily changed load has been investigated using an in situ gear test rig developed at the LKT. The in situ test method is based on analysing the timing differences between the index pulses of rotary encoders on the input and output shaft of the test rig. The loading torque was varied between two levels and compared to the permanently applied equivalent average load in terms of the resulting tooth flank wear. Moreover, the number of load changes has been varied to analyse the influence of load changes on the gear wear. The results show that the applied load spectrum determines the resulting tooth flank wear even if the average applied load is the same. Moreover, it could be shown that the sequence of the applied load, i.e., the load history, plays an important role, since the applied load and the duration of the applied load within the run-in-stage disproportionately affect the wear behaviour over time. Full article
(This article belongs to the Special Issue Plastics II)
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