Research

Jump to: Review

10 pages, 1265 KiB

Open AccessArticle

Synthesis of Dense 1,2,3-Triazole Oligomers Consisting Preferentially of 1,5-Disubstituted Units via Ruthenium(II)-Catalyzed Azide–Alkyne Cycloaddition

by Ryoichi Taguchi, Masaki Nakahata, Yuri Kamon and Akihito Hashidzume

Polymers 2023, 15(9), 2199; https://doi.org/10.3390/polym15092199 - 05 May 2023

Cited by 1 | Viewed by 1323

Abstract

Ruthenium(II)-catalyzed azide–alkyne cycloaddition (RuAAC) polymerization of t-butyl 4-azido-5-hexynoate (tBuAH), i.e., a heterobifunctional monomer carrying azide and alkyne moieties, was investigated in this study. RuAAC of the monofunctional precursors of tBuAH yielded a dimer possessing a 1,5-disubstituted 1,2,3-triazole moiety. ¹H NMR data [...] Read more.

Ruthenium(II)-catalyzed azide–alkyne cycloaddition (RuAAC) polymerization of t-butyl 4-azido-5-hexynoate (tBuAH), i.e., a heterobifunctional monomer carrying azide and alkyne moieties, was investigated in this study. RuAAC of the monofunctional precursors of tBuAH yielded a dimer possessing a 1,5-disubstituted 1,2,3-triazole moiety. ¹H NMR data showed that the dimer was a mixture of diastereomers. Polymerization of tBuAH using ruthenium(II) (Ru(II)) catalysts produced oligomers of M_w ≈ (2.7–3.6) × 10³ consisting of 1,5-disubstituted 1,2,3-triazole units (1,5-units) as well as 1,4-disubstituted 1,2,3-triazole units (1,4-units). The fractions of 1,5-unit (f_1,5) were roughly estimated to be ca. 0.8 by comparison of signals of the methine and triazole protons in ¹H NMR spectra, indicating that RuAAC proceeded preferentially and thermal Huisgen cycloaddition (HC) somehow took place during the polymerization. The oligomer samples obtained were also characterized by solubility test, size exclusion chromatography (SEC), ultraviolet-visible (UV-Vis) absorption spectroscopy, and thermogravimetric analysis (TGA). The UV-Vis and TGA data indicated that the oligomer samples contained a substantial amount of Ru(II) catalysts. To the best of our knowledge, this is the first report on dense 1,2,3-triazole oligomers consisting of 1,5-units linked via a carbon atom. Full article

(This article belongs to the Special Issue State-of-the-Art Polymer Science and Technology in Japan (2021,2022))

► Show Figures

Graphical abstract

11 pages, 1516 KiB

Open AccessArticle

Variation of the Tensile Properties of Basalt-Fiber-Reinforced Polybutylene Succinate Matrix Composites during Microbial Degradation

by Lovisa Rova, Hiroki Kurita, Shinji Kudo, Sho Hatayama, Teruyoshi Kanno, Alia Gallet--Pandellé and Fumio Narita

Polymers 2023, 15(7), 1796; https://doi.org/10.3390/polym15071796 - 05 Apr 2023

Cited by 2 | Viewed by 1544

Abstract

Little is known about how the strength of biodegradable polymers changes during decomposition. This study investigated the changes in the tensile properties of polybutylene succinate (PBS) and basalt-fiber (BF)-reinforced PBS (PBS-BF) composite sheets during degradation in bacterial solutions. Seven days after the start [...] Read more.

Little is known about how the strength of biodegradable polymers changes during decomposition. This study investigated the changes in the tensile properties of polybutylene succinate (PBS) and basalt-fiber (BF)-reinforced PBS (PBS-BF) composite sheets during degradation in bacterial solutions. Seven days after the start of the experiment, the elongation at break of the PBS specimens decreased significantly, and the PBS-BF composite specimens were characterized by barely any change in ultimate tensile strength (UTS) after immersion in the bacteria-free medium for 7 and 56 days. Meanwhile, when immersed in the bacterial solution, the UTS of the PBS-BF composite specimens showed a tendency to decrease after 7 days. After 56 days, the UTS decreased to about half of its value immediately after fabrication. The degradation of the material was attributed to infiltration of the bacterial solution into structurally weak areas, causing decomposition throughout the material. Full article

(This article belongs to the Special Issue State-of-the-Art Polymer Science and Technology in Japan (2021,2022))

► Show Figures

Figure 1

14 pages, 3107 KiB

Open AccessArticle

A Thermo-Responsive Polymer Micelle with a Liquid Crystalline Core

by Yoko Mizoue, Rintaro Takahashi, Kazuo Sakurai and Shin-ichi Yusa

Polymers 2023, 15(3), 770; https://doi.org/10.3390/polym15030770 - 02 Feb 2023

Cited by 2 | Viewed by 1922

Abstract

An amphiphilic diblock copolymer (PChM-PNIPAM), composed of poly(cholesteryl 6-methacryloyloxy hexanoate) (PChM) and poly(N-isopropyl acrylamide) (PNIPAM) blocks, was prepared via reversible addition–fragmentation chain transfer radical polymerization. The PChM and PNIPAM blocks exhibited liquid crystalline behavior and a lower critical solution temperature (LCST), [...] Read more.

An amphiphilic diblock copolymer (PChM-PNIPAM), composed of poly(cholesteryl 6-methacryloyloxy hexanoate) (PChM) and poly(N-isopropyl acrylamide) (PNIPAM) blocks, was prepared via reversible addition–fragmentation chain transfer radical polymerization. The PChM and PNIPAM blocks exhibited liquid crystalline behavior and a lower critical solution temperature (LCST), respectively. PChM-PNIPAM formed water-soluble polymer micelles in water below the LCST because of hydrophobic interactions of the PChM blocks. The PChM and PNIPAM blocks formed the core and hydrophilic shell of the micelles, respectively. With increasing temperature, the molecular motion of the pendant cholesteryl groups increased, and a liquid crystalline phase transition occurred from an amorphous state in the core. With further increases in temperature, the PNIPAM block in the shell exhibited the LCST and dehydrated. Hydrophobic interactions of the PNIPAM shells resulted in inter-micellar aggregation above the LCST. Full article

(This article belongs to the Special Issue State-of-the-Art Polymer Science and Technology in Japan (2021,2022))

► Show Figures

Figure 1

13 pages, 2216 KiB

Open AccessArticle

Kinetics of Micellization and Liquid–Liquid Phase Separation in Dilute Block Copolymer Solutions

by Takahiro Sato

Polymers 2023, 15(3), 708; https://doi.org/10.3390/polym15030708 - 31 Jan 2023

Cited by 2 | Viewed by 1258

Abstract

A lattice theory for block copolymer solutions near the boundary between the micellization and liquid–liquid phase separation regions proposes a new kinetic process of micellization where small concentrated-phase droplets are first formed and then transformed into micelles in the early stage of micellization. [...] Read more.

A lattice theory for block copolymer solutions near the boundary between the micellization and liquid–liquid phase separation regions proposes a new kinetic process of micellization where small concentrated-phase droplets are first formed and then transformed into micelles in the early stage of micellization. Moreover, the thermodynamically stable concentrated phase formed from metastable micelles by a unique ripening process in the late stage of phase separation, where the growing concentrated-phase droplet size is proportional to the square root of the time. Full article

(This article belongs to the Special Issue State-of-the-Art Polymer Science and Technology in Japan (2021,2022))

► Show Figures

Graphical abstract

7 pages, 2227 KiB

Open AccessCommunication

Development of a Method for Peeling Off Paper from Celluloid Pictures for Animation Films

by Masahiro Kaneko, Joon Yang Kim, Minori Ishida, Mika Kawai and Tetsu Mitsumata

Polymers 2023, 15(3), 690; https://doi.org/10.3390/polym15030690 - 30 Jan 2023

Cited by 2 | Viewed by 1529

Abstract

During the storage of celluloid pictures for animation films over half a century, an interleave paper adhered to acrylic paint. The purpose of this study is to establish a methodology to cleanly remove the paper from the paint. A layered film, a replica [...] Read more.

During the storage of celluloid pictures for animation films over half a century, an interleave paper adhered to acrylic paint. The purpose of this study is to establish a methodology to cleanly remove the paper from the paint. A layered film, a replica of the celluloid pictures, adhered with paper was prepared and immersed in water or ethanol. The effect of these solvents on the peeling behavior was investigated using a peel test. The maximum peel force for the dry layered film in was distributed at ~0.5 N, independently of the peel speed. The peel force was significantly reduced after the layered film was immersed in pure water or ethanol. A morphological observation revealed that the dry paper was peeled off via the cohesive failure of the paper. After the layered film was immersed in pure water, the paper was also peeled off via cohesive failure. The layered film immersed in ethanol was peeled off at the paper/paint interface. To clear the effect of the volume change in the paint on peel behavior, the relative volume was determined via image analysis. The relative volume of paint was 1.56 in pure water and 1.37 in ethanol. It can be considered that the large difference in the volume of paint induces a large shear stress at the paint/paper interface. Full article

(This article belongs to the Special Issue State-of-the-Art Polymer Science and Technology in Japan (2021,2022))

► Show Figures

Figure 1

15 pages, 6719 KiB

Open AccessArticle

Photocrosslinked Fish Collagen Peptide/Chitin Nanofiber Composite Hydrogels from Marine Resources: Preparation, Mechanical Properties, and an In Vitro Study

by Shinya Yano, Kei Yamaguchi, Mitsuhiro Shibata, Shinsuke Ifuku and Naozumi Teramoto

Polymers 2023, 15(3), 682; https://doi.org/10.3390/polym15030682 - 29 Jan 2023

Cited by 3 | Viewed by 2042

Abstract

Fish collagen peptide (FCP) is a water-soluble polymer with easy accessibility, bioactivity, and reactivity due to its solubility. The gelation of FCP can be carried out by chemical crosslinking, but the mechanical strength of FCP hydrogel is very low because of its intrinsically [...] Read more.

Fish collagen peptide (FCP) is a water-soluble polymer with easy accessibility, bioactivity, and reactivity due to its solubility. The gelation of FCP can be carried out by chemical crosslinking, but the mechanical strength of FCP hydrogel is very low because of its intrinsically low molecular weight. Therefore, the mechanical properties of FCP gel should be improved for its wider application as a biomaterial. In this study, we investigated the mechanical properties of M-FCP gel in the context of understanding the influence of chitin nanofibers (CHNFs) on FCP hydrogels. FCP with a number average molecular weight (M_n) of ca. 5000 was reacted with glycidyl methacrylate (GMA) and used for the preparation of photocrosslinked hydrogels. Subsequently, composite hydrogels of methacrylate-modified FCP (M-FCP) and CHNF were prepared by the photoirradiation of a solution of M-FCP containing dispersed CHNF at an intensity of ~60 mW/cm² for 450 s in the presence of 2-hydroxy-1-[4-(hydroxyethoxy)phenyl]-2-methyl-1-propanone (Irgacure 2959) as a photoinitiator. Compression and tensile tests of the FCP hydrogels were carried out using a universal tester. The compression and tensile strength of the hydrogel increased 10-fold and 4-fold, respectively, by the addition of 0.6% CHNF (20% M-FCP), and Young’s modulus increased 2.5-fold (20% M-FCP). The highest compression strength of the M-FCP/CHNF hydrogel was ~300 kPa. Cell proliferation tests using fibroblast cells revealed that the hydrogel with CHNF showed good cell compatibility. The cells showed good adhesion on the M-FCP gel with CHNF, and the growth of fibroblast cells after 7 days was higher on the M-FCP/CHNF gel than on the M-FCP gel without CHNF. In conclusion, we found that CHNF improved the mechanical properties as well as the fibroblast cell compatibility, indicating that M-FCP hydrogels reinforced with CHNF are useful as scaffolds and wound-dressing materials. Full article

(This article belongs to the Special Issue State-of-the-Art Polymer Science and Technology in Japan (2021,2022))

► Show Figures

Graphical abstract

9 pages, 2286 KiB

Open AccessEditor’s ChoiceArticle

Self- and Cross-Fusing of Furan-Based Polyurea Gels Dynamically Cross-Linked with Maleimides

by Takuya Kumakura, Kenji Takada and Tatsuo Kaneko

Polymers 2023, 15(2), 341; https://doi.org/10.3390/polym15020341 - 09 Jan 2023

Cited by 1 | Viewed by 1586

Abstract

Bio-based polyureas (PUs) with main-chain furan rings were synthesized by the polyaddition of 2,5-bis(aminomethyl)furan with various diisocyanates, such as methylene diphenyl diisocyanate. Several PU’s were soluble in polar organic solvents, and were cast to form thermomechanically stable films with softening temperatures of over [...] Read more.

Bio-based polyureas (PUs) with main-chain furan rings were synthesized by the polyaddition of 2,5-bis(aminomethyl)furan with various diisocyanates, such as methylene diphenyl diisocyanate. Several PU’s were soluble in polar organic solvents, and were cast to form thermomechanically stable films with softening temperatures of over 100 °C. The furan rings of the PU main chains underwent a dynamic Diels-Alder (DA) reaction with bismaleimide (BMI) cross-linkers. While the mixed solution of PU and BMI did not show any apparent signs of reaction at room temperature, the DA reaction proceeded to form gels upon heating to 60 °C, which became a solution again by further heating to 80 °C (retro-DA reaction). The solution phase was maintained by rapid quenching from 80 °C to room temperature, while the gel was reformed upon slow cooling. The recovered gels exhibited self-healing properties. A scratch made by a hot knife at temperatures above 80 °C disappeared spontaneously. When two different gels were cut using a knife at room temperature, placed in contact with each other, and heated to 60 °C, they fused. The ability to control the DA/retro-DA reaction allowed gels of varying composition to heal. Full article

(This article belongs to the Special Issue State-of-the-Art Polymer Science and Technology in Japan (2021,2022))

► Show Figures

Graphical abstract

11 pages, 4989 KiB

Open AccessArticle

4-Amino-TEMPO-Immobilized Polymer Monolith: Preparations, and Recycling Performance of Catalyst for Alcohol Oxidation

by Tomoki Imoto, Hikaru Matsumoto, Seiya Nonaka, Keita Shichijo, Masanori Nagao, Hisashi Shimakoshi, Yu Hoshino and Yoshiko Miura

Polymers 2022, 14(23), 5123; https://doi.org/10.3390/polym14235123 - 24 Nov 2022

Cited by 1 | Viewed by 1870

Abstract

Continuous flow reactors with immobilized catalysts are in great demand in various industries, to achieve easy separation, regeneration, and recycling of catalysts from products. Oxidation of alcohols with 4-amino-TEMPO-immobilized monolith catalyst was investigated in batch and continuous flow systems. The polymer monoliths were [...] Read more.

Continuous flow reactors with immobilized catalysts are in great demand in various industries, to achieve easy separation, regeneration, and recycling of catalysts from products. Oxidation of alcohols with 4-amino-TEMPO-immobilized monolith catalyst was investigated in batch and continuous flow systems. The polymer monoliths were prepared by polymerization-induced phase separation using styrene derivatives, and 4-amino-TEMPO was immobilized on the polymer monolith with a flow reaction. The prepared 4-amino-TEMPO-immobilized monoliths showed high permeability, due to their high porosity. In batch oxidation, the reaction rate of 4-amino-TEMPO-immobilized monolith varied with stirring. In flow oxidation, the eluent permeated without clogging, and efficient flow oxidation was possible with residence times of 2–8 min. In the recycling test of the flow oxidation reaction, the catalyst could be used at least six times without catalyst deactivation. Full article

(This article belongs to the Special Issue State-of-the-Art Polymer Science and Technology in Japan (2021,2022))

► Show Figures

Graphical abstract

15 pages, 2890 KiB

Open AccessEditor’s ChoiceArticle

Threonine-Based Stimuli-Responsive Nanoparticles with Aggregation-Induced Emission-Type Fixed Cores for Detection of Amines in Aqueous Solutions

by Keita Kataoka, Kazuhiro Nakabayashi, Chen-Tsyr Lo and Hideharu Mori

Polymers 2022, 14(7), 1362; https://doi.org/10.3390/polym14071362 - 27 Mar 2022

Cited by 2 | Viewed by 1750

Abstract

Stimuli-responsive polymeric nanoparticles (NPs) exhibit reversible changes in the dispersion or aggregation state in response to external stimuli. In this context, we designed and synthesized core-shell NPs with threonine-containing weak polyelectrolyte shells and fluorescent cross-linked cores, which are applicable for the detection of [...] Read more.

Stimuli-responsive polymeric nanoparticles (NPs) exhibit reversible changes in the dispersion or aggregation state in response to external stimuli. In this context, we designed and synthesized core-shell NPs with threonine-containing weak polyelectrolyte shells and fluorescent cross-linked cores, which are applicable for the detection of pH changes and amine compounds in aqueous solution. Stable and uniform NP(dTh) and NP(Fl), consisting of fluorescent symmetric diphenyl dithiophene (dTh) and diphenyl fluorene (Fl) cross-linked cores, were prepared by site-selective Suzuki coupling reactions in self-assembled block copolymer. NP(Fl) with the Fl unit in the core showed a high fluorescence intensity in different solvents, which is regarded as an aggregation-induced emission-type NP showing strong emission in aggregated states in the cross-linked core. Unimodal NPs were observed in water at different pH values, and the diameter of NP(Fl) changed from 122 (pH = 2) to 220 nm (pH = 11). Furthermore, pH-dependent changes of the fluorescence peak positions and intensities were detected, which may be due to the core aggregation derived from the deprotonation of the threonine-based shell fragment. Specific interactions between the threonine-based shell of NP(Fl) and amine compounds (triethylamine and p-phenylenediamine) resulted in fluorescence quenching, suggesting the feasibility of fluorescent amine detection. Full article

(This article belongs to the Special Issue State-of-the-Art Polymer Science and Technology in Japan (2021,2022))

► Show Figures

Graphical abstract

14 pages, 13131 KiB

Open AccessArticle

Separated Micelles Formation of pH-Responsive Random and Block Copolymers Containing Phosphorylcholine Groups

by Thi Lien Nguyen, Kazuhiko Ishihara and Shin-ichi Yusa

Polymers 2022, 14(3), 577; https://doi.org/10.3390/polym14030577 - 31 Jan 2022

Cited by 4 | Viewed by 2508

Abstract

The self-assembly of pH-responsive random and block copolymers composed of 2-(N,N-diisopropylamino)ethyl methacrylate and 2-methacryloyloxyethyl phosphorylcholine was investigated in aqueous media. Their pH-responsive behaviors were investigated in aqueous media by dynamic light scattering (DLS) and fluorescence measurements using a pyrene hydrophobic fluorescence [...] Read more.

The self-assembly of pH-responsive random and block copolymers composed of 2-(N,N-diisopropylamino)ethyl methacrylate and 2-methacryloyloxyethyl phosphorylcholine was investigated in aqueous media. Their pH-responsive behaviors were investigated in aqueous media by dynamic light scattering (DLS) and fluorescence measurements using a pyrene hydrophobic fluorescence probe. In an acidic environment, these copolymers existed as single polymer chains that did not interact with each other. In contrast, upon increasing the pH of the solution above the critical value of ~8, separated micelles were formed in the mixture, which was indicated by bimodal distribution in DLS results with radius of 4.5 and 10.4 nm, corresponding to the random and block copolymer micelles, respectively. Fluorescence resonance energy transfer efficiencies were near to zero in the mixture of the donor labeled block and acceptor labeled random copolymers under both acidic and basic pH. These results demonstrated the coexistence of two distinct micelles. Full article

(This article belongs to the Special Issue State-of-the-Art Polymer Science and Technology in Japan (2021,2022))

► Show Figures

Graphical abstract

16 pages, 3152 KiB

Open AccessEditor’s ChoiceArticle

Synthesis and Characterization of White-Light Luminescent End-Capped Polyimides Based on FRET and Excited State Intramolecular Proton Transfer

by Atsuko Tabuchi, Teruaki Hayakawa, Shigeki Kuwata, Ryohei Ishige and Shinji Ando

Polymers 2021, 13(22), 4050; https://doi.org/10.3390/polym13224050 - 22 Nov 2021

Cited by 4 | Viewed by 2290

Abstract

N-cyclohexylphthalimide-substituted trifluoroacetylamino (CF₃CONH-) group (3TfAPI), which forms an intramolecular hydrogen bond, was synthesized, and it exhibited a bright yellow fluorescence owing to the excited-state intramolecular proton transfer (ESIPT) in the solution and crystalline states. In addition, CF₃CONH-substituted phthalic [...] Read more.

N-cyclohexylphthalimide-substituted trifluoroacetylamino (CF₃CONH-) group (3TfAPI), which forms an intramolecular hydrogen bond, was synthesized, and it exhibited a bright yellow fluorescence owing to the excited-state intramolecular proton transfer (ESIPT) in the solution and crystalline states. In addition, CF₃CONH-substituted phthalic anhydride (3TfAPA) was synthesized, which was attached to the termini of a blue-fluorescent semi-aromatic polyimide (PI) chain. Owing to the efficient Förster resonance energy transfer (FRET) occurring from the main chain to the termini and the suppression of deprotonation (anion formation) at the 3TfAPA moiety by H₂SO₄ doping, the resulting PI films display bright white fluorescence. Moreover, the enhancement of the chain rigidity by substituting the diamine moiety results in an increase in the quantum yield of white fluorescence (Φ) by a factor of 1.7, due to the suppression of local molecular motion. This material design strategy is promising for preparing thermally stable white-light fluorescent PIs applicable to solar spectral convertors, displays, and ICT devices. Full article

(This article belongs to the Special Issue State-of-the-Art Polymer Science and Technology in Japan (2021,2022))

► Show Figures

Graphical abstract

7 pages, 1002 KiB

Open AccessEditor’s ChoiceArticle

Development of Long Wavelength Light-Absorptive Homopolymers Based on Pentaazaphenalene by Regioselective Oxidative Polymerization

by Hiroyuki Watanabe, Kazuo Tanaka and Yoshiki Chujo

Polymers 2021, 13(22), 4021; https://doi.org/10.3390/polym13224021 - 20 Nov 2021

Cited by 6 | Viewed by 1492

Abstract

We report the synthesis and absorption properties of homopolymers consisting of 1,3,4,6,9b-pentaazaphenalene (5AP). Oxidative polymerization in the Scholl reaction was accomplished, and various lengths of homopolymers can be isolated. It should be noted that we scarcely observed the generation of structural isomers at [...] Read more.

We report the synthesis and absorption properties of homopolymers consisting of 1,3,4,6,9b-pentaazaphenalene (5AP). Oxidative polymerization in the Scholl reaction was accomplished, and various lengths of homopolymers can be isolated. It should be noted that we scarcely observed the generation of structural isomers at the connecting points, which is often observed in this type of reaction. Therefore, we were able to evaluate electronic structures of the synthesized homopolymers. In addition, it was observed that absorption bands were obtained in the longer wavelength region than the monomer. The computer calculation suggests that the highest occupied molecular orbital (HOMO) energy levels could be lowered by electronic interaction through spatially-separated HOMOs of 5AP. Moreover, we can evaluate the extension of the conjugated system through the meta-substituted skeleton and distance dependency of the main-chain conjugation. Full article

(This article belongs to the Special Issue State-of-the-Art Polymer Science and Technology in Japan (2021,2022))

► Show Figures

Graphical abstract

Review

Jump to: Research

44 pages, 19950 KiB

Open AccessEditor’s ChoiceReview

Hybridization of Wide-Angle X-ray and Neutron Diffraction Techniques in the Crystal Structure Analyses of Synthetic Polymers

by Kohji Tashiro, Katsuhiro Kusaka, Hiroko Yamamoto, Takaaki Hosoya, Shuji Okada and Takashi Ohhara

Polymers 2023, 15(2), 465; https://doi.org/10.3390/polym15020465 - 16 Jan 2023

Cited by 1 | Viewed by 2076

Abstract

The development in the crystal structure analysis of synthetic polymers using the hybridized combination of wide-angle X-ray and neutron diffraction (WAXD and WAND, respectively) techniques has been reviewed with many case studies performed by the authors. At first, the technical development was reviewed, [...] Read more.

The development in the crystal structure analysis of synthetic polymers using the hybridized combination of wide-angle X-ray and neutron diffraction (WAXD and WAND, respectively) techniques has been reviewed with many case studies performed by the authors. At first, the technical development was reviewed, in which the usage of high-energy synchrotron X-ray source was emphasized for increasing the total number of the observable diffraction peaks, and several examples were introduced. Secondly, the usage of the WAND method was introduced, in which the successful extraction of hydrogen atomic positions was described. The third example is to show the importance for the hybrid combination of these two diffraction methods. The quantitative WAXD data analysis gave the crystal structures of at-poly(vinyl alcohol) (at-PVA) and at-PVA-iodine complex. However, the thus-proposed structure models were found not to reproduce the observed WAND data very much. The reason came from the remarkable difference in the atomic scattering powers of the constituting atomic species between WAXD and WAND phenomena. The introduction of statistical disorder solved this serious problem, which reproduced both of the observed WAXD and WAND data consistently. The more systematic combination of WAXD and WAND methods, or the so-called X-N method, was applied also to the quantitative evaluation of the bonded electron density distribution along the skeletal chains, where the results about polydiacetylene single crystals were presented as the first successful study. Finally, the application of WAND technique in the trace of structural changes induced under the application of external stress or temperature was described. The future perspective is described for the development of structural science of synthetic polymers on the basis of the combined WAXD/WAND techniques. Full article

(This article belongs to the Special Issue State-of-the-Art Polymer Science and Technology in Japan (2021,2022))

► Show Figures

Figure 1

Journal Menu

Journal Browser

State-of-the-Art Polymer Science and Technology in Japan (2021,2022)

Share This Special Issue

Special Issue Editors

Special Issue Information

Published Papers (13 papers)

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI