Article
Engineering, Chemical
Petros Oikonomou, Merope Sanopoulou, Kyriaki G. Papadokostaki
Summary: Blends of poly(vinyl alcohol) (PVA) and poly(vinyl pyrrolidone) (PVP) readily absorb water when exposed to external humidity. The physical properties of the blends, including glass transition temperature (Tg) and mechanical properties, are affected by the increase in water content, with a linear relation between the weight fraction of absorbed water and the blend composition observed. Differential scanning calorimetry results showed that the depression of Tg with increasing water content could be accurately described by empirical equations, and the Young modulus of hydrated samples experienced a significant decrease when the blend transitioned from a glassy to rubbery state.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2021)
Article
Polymer Science
Zhonghe Sun, Xing Mi, Yanan Yu, Wencheng Shi, Anchao Feng, Graeme Moad, San H. Thang
Summary: Xanthate-mediated RAFT polymerization has been used to prepare star-PVC with different molar masses, which can effectively reduce the glass-transition temperature of PVC and improve its ductility, showing the potential to be non-migratory plasticizers for PVC.
Article
Polymer Science
Riza Asmaa Saari, Ryota Maeno, Warinda Marujiwat, Muhammad Shahrulnizam Nasri, Kazuaki Matsumura, Masayuki Yamaguchi
Summary: The addition of lithium bromide significantly enhances the mechanical properties of PVA fibers by reducing crystallinity and hydrogen bonding between PVA chains. Lithium bromide is removed from the fibers during spinning, while maintaining strong hydrogen bonding within the fibers.
Article
Biochemistry & Molecular Biology
Giuseppe Porpora, Francesco Rusciano, Raffaele Pastore, Francesco Greco
Summary: Glass transition is an intriguing open issue in molecular liquids, and recent research has found that the relationship between macroscopic timescales and cage-jump quantities changes on approaching the glass transition.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Polymer Science
Lujuan Li, Xiaodong Xu, Lei Liu, Pingan Song, Qianqian Cao, Zhiguang Xu, Zhengping Fang, Hao Wang
Summary: The presence of water significantly reduces the mechanical strength of PVA but increases its plasticity. Additionally, water inclusion lowers the glass transition temperature of PVA, increases free volume, and promotes relaxation and mobility of PVA chains. This is mainly due to the plasticizing and lubricating effects of water on the PVA chains.
Article
Polymer Science
Bin Hu, Jan-Michael Carrillo, Liam Collins, Kevin S. Silmore, Jong Keum, Peter Bonnesen, Yangyang Wang, Scott Retterer, Rajeev Kumar, Bradley S. Lokitz
Summary: A strategy for facile synthesis of bottlebrush block copolymers with flexible backbones was developed. The utility of this strategy was demonstrated by grafting end-functionalized PMMA and PS onto the dually reactive block copolymer PGMA-b-PVDMA. Experimental and computational analysis showed a relationship between glass transition temperature and chain end fraction, highlighting the potential of this method to tailor polymer properties. The study also revealed multiscale structures in the samples using X-ray scattering methods and molecular dynamics simulations. The modular approach can be extended to other grafts, providing a powerful tool for synthesizing novel bottlebrush block copolymers with desired properties.
Article
Polymer Science
Bin Hu, Jan-Michael Carrillo, Liam Collins, Kevin S. Silmore, Jong Keum, Peter Bonnesen, Yangyang Wang, Scott Retterer, Rajeev Kumar, Bradley S. Lokitz
Summary: A strategy for facile synthesis of bottlebrush block copolymers with flexible backbones was developed, which demonstrated the potential to tailor polymer properties. By analyzing and simulating various copolymers, the relationship between the glass transition temperature and the fraction of chain ends was highlighted.
Article
Polymer Science
Seong Baek Yang, Mohammad Rezaul Karim, Jungeon Lee, Jeong Hyun Yeum, Sabina Yeasmin
Summary: Novel poly(vinyl alcohol)/poly(vinyl butyral-vinyl alcohol) films with improved hydrophobicity were prepared by saponification of poly(vinyl acetate)/poly(vinyl butyral) blend films. The saponification process was confirmed by various analysis techniques. The hydrophobicity of the films increased with increasing poly(vinyl butyral) content. The saponified films exhibited improved mechanical properties and unique surface characteristics. These films have potential applications in biomaterials, filters, and medical devices.
Article
Polymer Science
Yutaka Ohsedo, Wakana Ueno
Summary: By studying the formation behavior and properties of molecular hydrogels composed of polymer hydrogelators and water-soluble polymers, this research discovered a new type of molecular hydrogel material with thixotropic behavior and spinnable characteristics, which has potential importance in healthcare and medical applications.
Article
Chemistry, Physical
Kaito Sasaki, Masanobu Takatsuka, Naoki Shinyashiki, Kia L. Ngai
Summary: Linking the dynamics of mixtures of water with hydrophilic molecules and polymers and hydrated proteins to glass-forming substances is a common practice in research community. The dynamics of poly(vinyl pyrrolidone)-water mixtures resemble that of highly asymmetric mixtures, both governed by the same physics. This study expands the understanding of the physics behind the dynamics in polymer-water mixtures, with potential implications for hydrated proteins.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Polymer Science
Woohyuk Choi, Woojin Lee, Yeong Jun Yu, Rodney D. Priestley, Jae Woo Chung, Seung-Yeop Kwak
Summary: The glass transition dynamics of polymers play a crucial role in determining their properties. Pyrene-labeled and pyrene-doped flexible PVC plasticized by ultra-small branched star poly(epsilon-caprolactone) were prepared to observe changes in fluorescence intensities with temperature. The study revealed limited movement of the labeled pyrene moieties along the PVC chains due to cooperative reptation motion, and showed that an increase in USB-SPCL content in flexible PVC can decrease fluorescence intensity reduction degrees while also potentially leading to an increase under certain conditions.
Article
Thermodynamics
Marek Pyda, Marcin Skotnicki, Anna Czerniecka-Kubicka, Iwona Zarzyka
Summary: In this paper, the heat capacity of the liquid state above the glass transition temperature of poly(vinyl methyl ether) (PVME) was investigated. The experimental heat capacity was linked to molecular motions and calculated as the sum of vibrational, external, and conformational contributions. The results showed good agreement between computed and experimental data in the temperature range from 250 to 360 K.
THERMOCHIMICA ACTA
(2023)
Article
Chemistry, Multidisciplinary
Yingxu Song, Sumei Zhang, Jian Kang, Jinyao Chen, Ya Cao
Summary: Annealing PVA films at different temperatures affects the water absorption, leading to changes in the formation of PVA-iodine complexes. The amount of PVA segments with moderate hydration has a significant impact on the complexation process.
Article
Nanoscience & Nanotechnology
Yuyang Zhao, Jinrui Zhang, Gang Qiao, Dongshuai Hou, Biqin Dong, Hongyan Ma
Summary: This study investigates the synergistic effect of carboxylated carbon nanotubes and poly(vinyl alcohol) on the mechanical properties of cement paste. The results demonstrate that their combination significantly increases the flexural strength of the cement paste and the strength enhancement mechanism is revealed from the perspectives of cement matrix enhancement and interface enhancement.
ACS APPLIED NANO MATERIALS
(2022)
Article
Polymer Science
Hamid Reza Hedayati, Manounchehr Khorasani, Mostafa Ahmadi, Nicholas Ballard
Summary: In this study, well-defined and linear PVAc was synthesized using RAFT polymerization method, overcoming the difficulties in controlling molecular weight distribution during the hydrolysis of PVAc. This offers a potential route to the production of PVAc and PVA products with uniform properties.
Article
Polymer Science
Chaofu Wu
JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS
(2017)
Article
Biochemistry & Molecular Biology
Chaofu Wu
JOURNAL OF MOLECULAR MODELING
(2017)
Article
Polymer Science
C. Wu
MACROMOLECULAR THEORY AND SIMULATIONS
(2018)
Article
Polymer Science
Chaofu Wu
Article
Materials Science, Multidisciplinary
Chaofu Wu
COMPUTATIONAL MATERIALS SCIENCE
(2019)
Article
Biochemistry & Molecular Biology
Chaofu Wu
JOURNAL OF MOLECULAR MODELING
(2018)
Article
Chemistry, Physical
Chaofu Wu
JOURNAL OF PHYSICAL CHEMISTRY C
(2019)
Article
Materials Science, Multidisciplinary
Chaofu Wu
COMPUTATIONAL MATERIALS SCIENCE
(2020)
Article
Polymer Science
Chaofu Wu
MACROMOLECULAR THEORY AND SIMULATIONS
(2020)
Article
Chemistry, Physical
Chaofu Wu
MOLECULAR SIMULATION
(2020)
Article
Materials Science, Multidisciplinary
Chaofu Wu
Summary: The proposed embedded model accurately determines the glass transition temperature and equilibrium melting point of the semicrystalline polymer by considering the interaction energy between the nanocrystal and its amorphous environment, providing a quick and accurate prediction for the T-m of a crystallizing polymer.
COMPUTATIONAL MATERIALS SCIENCE
(2021)
Article
Chemistry, Physical
Chaofu Wu, Kewen Li, Xutao Ning, Lei Zhang
Summary: The study introduces a charge-based mapping scheme for systematically derived coarse-grained models, successfully simulating the thermomechanical properties of two typical polymers with good agreement with experimental data.
JOURNAL OF PHYSICAL CHEMISTRY B
(2021)
Article
Biochemistry & Molecular Biology
Chaofu Wu
Summary: This study introduces virtual sites and elastic network bonds to improve the structural and volumetric property-based multiscale coarse-grained (CG) models. By extensively molecular dynamics simulations, the thermomechanical properties of two stereoregular polymer bulks are reasonably reproduced with the so-parameterized CG potentials, including the attractive nature of electrostatic interactions and the tacticity effects on glass transition temperatures (T-g).
JOURNAL OF MOLECULAR MODELING
(2022)
Article
Chemistry, Physical
Chaofu Wu
Summary: By simulating melted poly(ethylene oxide) thin films, it was found that thin films thinner than a critical value would transform into fibers. The critical film thickness was observed to increase with the number of chains and slightly change with temperature; the outermost surface layers exhibited the greatest movements.
JOURNAL OF PHYSICAL CHEMISTRY B
(2022)
Article
Chemistry, Physical
Chaofu Wu
JOURNAL OF PHYSICAL CHEMISTRY B
(2020)
Article
Polymer Science
Yuanzhang Jiang, Xuyi Wang, Yanting Han, Dakai Gong, Yingchun Gu, Lin Tan
Summary: In this study, FeCl3 and poly(acrylic acid) (PAA) were doped into waterborne polyurethanes (WPUs) to create multifunctional materials with self-healing and antimicrobial properties. WPU/Fe/PAA-5.5, containing 5.5 wt % PAA, exhibited excellent mechanical properties, strong self-healing capabilities, and an impressive antimicrobial rate of over 90%. These supramolecular films were also highly recyclable through hot-pressing.
Article
Polymer Science
Longyu Tian, Min Wang, Guangming Liao, Baoliang Liu, Sujuan Zhang, Yucheng Sun, Zhen Meng, Jintao Zhang, Zaijun Lu
Summary: Two kinds of benzoxazine monomers were synthesized and used to prepare polybenzoxazine anion exchange membranes (AEMs) with quaternary ammonium functionalization. The LQPBZ AEM exhibited better ion conductivity and alkaline stability.
Article
Polymer Science
Claire A. Lemarchand
Summary: This study investigates the shock behavior of three different polymers through molecular dynamics simulations. The results reveal specificities in the shock behavior of polymers, including deviations from the linear relation between shock velocity and particle velocity, as well as differences in shear stress relaxation behind the shock front. It is found that the deviation of the Hugoniot locus is related to the change in the relative contribution of bonding and non-bonding potential energies, while polymers with higher glass transition temperatures exhibit slower shear stress relaxation.
Article
Polymer Science
Zengquan Liu, Xiaochun Yin, He Zhang, Shuo Gao, Qinglin Kuang, Yanhong Feng
Summary: A powder solid-state extension (PSSE) technology was proposed to address the high melt viscosity issue of UHMWPE. By uniaxial extension and sintering in the solid state, a highly self-reinforced material was prepared. X-ray diffraction and scattering techniques were used to study the structural evolution during the PSSE process, and a solid-phase induced transformation model was established.
Article
Polymer Science
Zhike Li, Anyu Luo, Rui Zhou, Xin Li, Haiyan Li
Summary: A novel high temperature resistance IL@SiO2 nanocapsules were successfully prepared and their friction and wear properties in PA6 composites were studied. The addition of IL@SiO2 nanocapsules reduced the friction coefficient and wear rate without affecting the mechanical properties of PA6. The synergy between the IL core and SiO2 wall in the nanocapsules improved the self-lubricating performance of the PA6 composites.
Article
Polymer Science
Xin Liu, Xuhong Guo, Qi Liao
Summary: In this study, an algorithm for accurately estimating viscosity is developed using molecular dynamics simulations and the Green-Kubo formula. This algorithm can be applied to complex systems with long correlations, such as macromolecular and biological simulation systems.
Article
Polymer Science
Hao Pu, Yun-Lei Hou, Jing -Zhou Chen, Dong -Lin Zhao
Summary: The use of modified graphene improves the interfacial adherence of carbon fibers to epoxy resin, resulting in enhanced interfacial and bending properties of CF and matrix in CF/EP composites, as well as increased interlaminar shear strength and flexural strength.
Article
Polymer Science
Wei-Chung Ke, Jin-Wei Lin, Manohar Reddy Busireddy, Yueh-Hsing Lee, Jiun-Tai Chen, Chain-Shu Hsu
Summary: This study introduces a crosslinkable monomer, TAIC, to synthesize three crosslinked polyimide films, which exhibit improved thermal, mechanical, and dielectric properties. The introduction of TAIC enhances the tensile strength, reduces the dielectric constant and dielectric loss, and decreases the coefficient of thermal expansion of the polyimide films.
Article
Polymer Science
Alex Kwasi Kumi, Ruiling Fan, Ye Chen, Yumei Zhang
Summary: The difference in leaching of amylopectin from cellulose/amylopectin/1-butyl-3-methylimidazolium chloride ([Bmim][Cl]) blends during regeneration in water and aqueous ethanol has been studied. Molecular dynamics simulations showed that the dissolution and regeneration mechanisms of amylopectin in [Bmim][Cl] are similar to cellulose in ionic liquids. Water regeneration leads to weak electrostatic interactions, resulting in high leaching of amylopectin. In contrast, ethanol-water interactions enhance electrostatic interactions among amylopectin chains, limiting amylopectin leaching in aqueous ethanol.
Article
Polymer Science
Xi Zeng, Junwei Zhou, Junbiao Peng, Chunsheng Zhang, Danling Wang, Yihu Song, Qiang Zheng
Summary: This study utilizes an oligomer deep eutectic solvent (DES) based on polyethylene glycol to regulate the vulcanization kinetics of rubber. The results show that the DES can accelerate vulcanization at low temperatures without affecting the crosslinking density and Mullins effect.
Article
Polymer Science
Qianqian Yue, Yongfei Peng, Xingjian Liu, Aihua He, Huarong Nie
Summary: The addition of metal deactivators can effectively suppress the aging of TBIR, prolong its lifespan, and have no negative effects on its physical and processing properties. These research findings are of great importance for improving the stability and aging resistance of polymers.
Article
Polymer Science
J. Gomez-Caturla, J. Ivorra-Martinez, R. Tejada-Oliveros, V Moreno, D. Garcia-Garcia, R. Balart
Summary: This work focuses on the development of environmentally friendly PLA formulations by using different esters derived from geraniol as plasticizers. The results show that these esters have good compatibility with PLA, and they can effectively enhance the elongation and plasticity of PLA, reduce its glass transition temperature, and slightly improve its water absorption capabilities.
Article
Polymer Science
Dandan Li, Zhaohui Lu, Zhao Ke, Ke Xu, Fengna Dai, Youhai Yu, Guangtao Qian, Chunhai Chen
Summary: In this study, cross-linked PI aerogel membranes with low dielectric constant and high moisture resistance were prepared by co-polymerization and scraping coating technology. The incorporation of fluorinated blocks and benzimidazole ring structures resulted in novel PI aerogel membranes with fascinating dielectric properties and outstanding moisture resistance.
Article
Polymer Science
Zhaoyang Chu, Qing Zhang, Haihua Luo, Han Zhou, Fapei Zhang, Wei Chen, Wenhua Zhang
Summary: Multi-physical fields solution processing strategy is a universal and facile method for preparing various conjugated polymer films and high-performance devices. In this study, we employed a combined microfluidic flow and ultrasonication strategy (FU) for processing CP solutions, and found a pronounced synergetic effect in promoting the pre-ordering of chains in solution. The conformation order and anisotropy of the solution were revealed through various characterizations. A non-classical nucleation model for polymer crystallization in non-equilibrium solution processing was confirmed. The roles of microfluidic flow and ultrasonication in chain aggregation and crystallization were addressed through multi-physical simulations. Compared to pristine solutions, the FU strategy showed improved solution anisotropy and crystallization kinetics, resulting in higher crystallinity in films and increased mobilities in OFET devices. The FU processing strategy provides a universal approach for regulating chain conformation and aggregation in conjugated polymer solutions.
