Article
Materials Science, Characterization & Testing
Yuanjin Zhao, Chenguang Liu, Huafeng Shao, Aihua He
Summary: The creep resistance of polymer, especially isotactic polybutene-1 (iPB), is crucial for ensuring the dimensional stability of products under stress. This study investigates the effects of chain information, including weight-average molecular weight (Mw) and aggregate structures, on the creep behavior of iPB. It was found that increasing Mw, isotacticity, or the configurational sequence mmmm can enhance the creep resistance of iPB, with the latter playing a more important role in adjusting the aggregation structure of the final product. The findings provide guidance for synthesizing high-performance iPB for high-temperature pipe applications.
Article
Polymer Science
Morteza Abazari, Roghayeh Jamjah, Naeimeh Bahri-Laleh, Ahad Hanifpour
Summary: A high-performance three-metallic catalyst for ethylene polymerization was synthesized and characterized, showing high specific surface area and activity in the polymerization reaction. Studies on possible interactions between the chlorinating agent and catalytic reagents were conducted using density functional theory simulation.
Article
Polymer Science
Qingtao Niu, Junying Zhang, Aihua He
Summary: In this study, copolymerizations of isoprene and butadiene were conducted using different alkylaluminium-activated Ziegler-Natta catalysts. The use of AlEt3 resulted in higher activity and stereoselectivity, while AlOct(3) showed a higher Bd monomer reactivity ratio. The discrepancy between theoretical copolymer composition and experimental data mainly occurred in the initial polymerization stage.
POLYMER INTERNATIONAL
(2021)
Article
Chemistry, Physical
Meichen Han, Yuanjin Zhao, Shufang Luo, Xunzhang Fan, Aihua He
Summary: Diffusion controlled stereoregular polymerization was studied to investigate the relations between catalyst granules fragmentation and growing and its catalytic features. Propylene (Pr) polymerization kinetics and Pr/butene-1 (Bt) sequence polymerization kinetics with spherical TiCl4/MgCl2 Ziegler-Natta catalyst were investigated. The results showed that the increase in Pr polymerization time had different influences on the [C*]/[Ti] and catalytic efficiency (CE) for Bt-stage polymerization in different stage, and the isotacticity and weight-average molecular weight (Mw) of iPB fractions decreased gradually with the increase in Pr polymerization time.
MOLECULAR CATALYSIS
(2023)
Article
Polymer Science
Hiren Bhajiwala, Virendrakumar Gupta
Summary: This study reported novel external donors and their applications with catalysts in the synthesis of Ultrahigh molecular weight polyethylene (UHMWPE). The results showed that the catalysts with external donors had increased molecular weight with decreased catalyst activity. Moreover, the addition of chain terminating agents significantly decreased molecular weight with minimal effect on catalyst activity.
Article
Polymer Science
Xiong Wang, Dong Wu, Xuemei Mu, Wenqian Kang, Guangquan Li, Anping Huang, Yuan Xie
Summary: POPs-supported Ziegler-Natta catalysts were designed for synthesis of iPP, showing good polymerization activity, high stereoregularity, and broad MWD by adding internal electron donor ID-2. The catalyst exhibited higher chain stereoregularity compared to MgCl2-supported Z-N catalysts with the same internal electron donor.
Article
Polymer Science
Kaixuan Dong, Junying Zhang, Aihua He
Summary: Polymer chain-end functionalization with polar groups can enhance the hydrophilicity of polymers. In this study, a facile synthesis strategy for amine-functionalized trans-1,4-polyisoprenes was proposed using DCHA as a chain-transfer agent with a Ziegler-Natta catalyst. The F-TPI samples were separated into low-molecular-weight and high-molecular-weight fractions with different capping efficiencies, showing improved hydrophilicity with increased CE.
Article
Chemistry, Physical
Reza Bazvand, Naeimeh Bahri-Laleh, Hossein Abedini, Mehdi Nekoomanesh, Albert Poater
Summary: The activation of MgCl2 through the formation of MgCl2 & nEtOH adducts is crucial in the preparation of high performance Ziegler-Natta catalysts for olefins polymerizations in industry. However, the precise structural characterization of these compounds has been neglected due to their complex microstructure. In this study, four MgCl2.nEtOH adducts with different ethanol content were prepared and thoroughly evaluated. Despite the similarities in FTIR spectra, the SEM images showed that the adducts with n = 3.2 had a sticky nature, leading to increased particle size and broader SPAN. XRD spectra confirmed the presence of distinct peaks related to the distorted MgCl2 structure, and the ratio of α-MgCl2 to β-MgCl2 increased with higher ethanol content, which was further supported by DFT calculations. However, it should be noted that this study only provides a simplified characterization of the adducts.
JOURNAL OF MOLECULAR STRUCTURE
(2023)
Article
Materials Science, Characterization & Testing
Weiping Zheng, Meichen Han, Yuanjin Zhao, Huafeng Shao, Aihua He
Summary: The Xyl-C5 method is recommended for accurate measurement and isolation of the HiPB fractions from PB samples, showing independence on the molecular weight of fractions.
Article
Chemistry, Multidisciplinary
Arash Shams, Mohammadreza Mehdizadeh, HamidReza Teimoury, Mehrsa Emami, Seyed Amin Mirmohammadi, Samahe Sadjadi, Eduard Bardaji, Albert Poater, Naeimeh Bahri-Laleh
Summary: The study on the pore architecture of Ziegler-Natta (ZN) catalysts in propylene polymerizations reveals its significant impact on catalyst activity, H2- and comonomer-response, and final polymer properties. The catalyst with larger pore diameter, Cat-A, shows slightly higher activities in homopolymerization and copolymerization experiments, resulting in copolymers with lower isotactic sequence length and lamellar thickness.
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
(2022)
Article
Engineering, Chemical
Harshad R. Patil, Sanjay Chauhan, Anurag Mishra, Rudra Prasad Choudhury, Virendrakumar Gupta
Summary: Copolymers of propylene/1-octene and propylene/1-hexene were synthesized in slurry phase polymerization. The effect of Al/Do and Al/Ti mole ratio variations on polymerization and copolymer properties was investigated. The incorporation of comonomer influenced the molecular weight distribution and isotacticity of the resultant copolymers. The copolymer of propylene/1-hexene had a lower melting point compared to the copolymer of propylene/1-octene. The copolymers had a broad molecular weight distribution compared to homo PP. C-13 NMR was used to quantitatively evaluate the incorporation of comonomer. Copolymerization of propylene with hexene resulted in a copolymer with a relatively higher amount of 1-hexene compared to the copolymer of propylene/1-octene with a similar catalyst system, which explains the lower peak melting points.
POLYMER ENGINEERING AND SCIENCE
(2022)
Article
Chemistry, Physical
Yansong Wu, Jian Li, Wei Ding, Tao Jiang
Summary: The MgCl2-supported Ziegler-Natta catalyst for propylene polymerization prepared via an in situ emulsion technique with new surfactants shows perfectly spherical particles, narrow size distribution, and low fine powder content. The catalyst demonstrates high activity, high bulk density, high stereospecificity, and excellent hydrogen sensitivity during propylene bulk polymerization. The produced polymer has a narrow particle size distribution and low fine powder content.
Article
Chemistry, Applied
Vladislav A. Tuskaev, Svetlana Ch. Gagieva, Dmitrii A. Kurmaev, Vyacheslav S. Bogdanov, Kasim F. Magomedov, Elena S. Mikhaylik, Evgenii K. Golubev, Mikhail I. Buzin, Galina G. Nikiforova, Viktor G. Vasil'ev, Viktor N. Khrustalev, Pavel V. Dorovatovskii, Artem V. Bakirov, Maksim A. Shcherbina, Pavel B. Dzhevakov, Boris M. Bulychev
Summary: New alkoxo-titanium(IV) complexes with diolate ligands show high activity in ethylene polymerization, producing ultra high molecular weight polyethylene suitable for high strength and high modulus films and tapes. These complexes can be scaled up without significant loss in productivity or polymer properties, as shown by structural analysis of UHMWPE samples.
APPLIED ORGANOMETALLIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Ann Charise Carino, Young Soo Ko
Summary: A MgCl2-supported Ziegler-Natta catalyst was synthesized in one step. The effect of feeding conditions of 2-ethyl-1-hexanol (EHA) and Mg/Al molar ratio in feed were investigated. Longer EHA feeding time and higher EHA concentration resulted in higher Ti content and activity in ethylene polymerization. A lower Mg/Al molar ratio in feed (M-1) caused lower Ti content with lower Ti binding energy, but showed high activity and higher molecular weight capability in ethylene-1-octene copolymerizations.
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
(2023)
Article
Chemistry, Physical
Kefeng Xie, Shengyuan Xu, Wei Hao, Jie Wang, Anping Huang, Yonghui Zhang
Summary: Ziegler-Natta (Z-N) catalyst is an important catalyst in the petrochemical industry, allowing large-scale production of polyolefins under mild conditions. The surface energy of MgCl2 is an effective descriptor for predicting catalyst performance.
APPLIED SURFACE SCIENCE
(2022)
Article
Polymer Science
Huafeng Shao, Zhanfei Lv, Zhaobo Sun, Chenguang Liu, Aihua He
Article
Polymer Science
Huafeng Shao, Shulei Wang, Xia Dong, Aihua He
JOURNAL OF MACROMOLECULAR SCIENCE PART B-PHYSICS
(2018)
Article
Chemistry, Applied
Zhaobo Sun, Yuefa Zhang, Huafeng Shao, Aihua He
REACTIVE & FUNCTIONAL POLYMERS
(2019)
Article
Polymer Science
Ya-Ping Ma, Wei-Ping Zheng, Chen-Guang Liu, Hua-Feng Shao, Hua-Rong Nie, Ai-Hua He
CHINESE JOURNAL OF POLYMER SCIENCE
(2020)
Article
Polymer Science
Huafeng Shao, Shuting Ren, Riguo Wang, Aihua He
Article
Materials Science, Multidisciplinary
Weiping Zheng, Dalin Du, Aihua He, Yaping Ma, Huafeng Shao, Chenguang Liu, Benjamin S. Hsiao
MATERIALS TODAY COMMUNICATIONS
(2020)
Article
Polymer Science
Wei-Ping Zheng, Ya-Ping Ma, Da-Lin Du, Ai-Hua He, Hua-Feng Shao, Chen-Guang Liu
Summary: The catalytic activity and stereospecificity of olefin polymerization are determined by the active centers, which are mysterious and controversial. Polymerization temperature and time have complex influences on catalyst activity and the isotacticity of the resulting polypropylene. Higher temperature results in higher activity and isotactic components, while appropriate polymerization time leads to full fragmentation of the catalyst with minimal diffusion limitations.
CHINESE JOURNAL OF POLYMER SCIENCE
(2021)
Article
Materials Science, Characterization & Testing
Weiping Zheng, Meichen Han, Yuanjin Zhao, Huafeng Shao, Aihua He
Summary: The Xyl-C5 method is recommended for accurate measurement and isolation of the HiPB fractions from PB samples, showing independence on the molecular weight of fractions.
Article
Polymer Science
Huafeng Shao, Qinrui Guo, Aihua He
Summary: A novel reactive compatibilizer trans-1,4-poly (isoprene-co-butadiene) (TBIR) is introduced to improve the thermo-oxidative aging resistance of NR/BR blends, resulting in better physical mechanical properties and improved filler dispersion. The total crosslinking density and poly-sulfide crosslinking density increase during aging, while the compatibility between NR and BR is enhanced by the addition of TBIR.
POLYMER DEGRADATION AND STABILITY
(2021)
Article
Materials Science, Multidisciplinary
Huafeng Shao, Xiaoxue Chen, Aihua He
Summary: A multi-block stereoregular copolymer of styrene and isoprene was successfully synthesized using a supported titanium Ziegler-Natta catalyst, showing higher reactivity of isoprene compared to styrene. Fractionation by n-hexane extraction revealed copolymers with varying lengths of trans-polyisoprene and isotactic polystyrene blocks. This work provides a novel approach for stereospecific copolymerization using traditional catalyst systems.
MATERIALS TODAY COMMUNICATIONS
(2022)
Article
Materials Science, Characterization & Testing
Huafeng Shao, Qinrui Guo, Aihua He
Summary: This study investigates the relationship between crosslinking structure and mechanical properties, dynamic properties, and microstructural evolution before and after thermo-oxidative aging in unfilled NR/BR blends. The results show that the polysulfide bond content and density decrease with increased thermo-oxidative aging time and increase with TBIR content.
Article
Chemistry, Multidisciplinary
Yaping Ma, Ning Zhang, Weiping Zheng, Weijia Xiao, Chenguang Liu, Aihua He, Huafeng Shao
CHEMICAL JOURNAL OF CHINESE UNIVERSITIES-CHINESE
(2020)
Article
Chemistry, Multidisciplinary
Qinrui Guo, Huafeng Shao, Aihua He
CHEMICAL JOURNAL OF CHINESE UNIVERSITIES-CHINESE
(2020)
Article
Chemistry, Multidisciplinary
Zhang Yuefa, Shao Huafeng, Wang Riguo, He Aihua
CHEMICAL JOURNAL OF CHINESE UNIVERSITIES-CHINESE
(2019)
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.
