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Chinese Journal of Polymer Science 2024年第6期42卷 775-786页

作者： Shuang-Cheng Li Wei-Jia Zhou Wen-Jie Wu Jun Shao Shui-Liang Chen Hao-Qing Hou Sheng Xiang College of Chemistry&Chemical Engineering and Nanofiber Engineering Center of Jiangxi Province Jiangxi Normal UniversityNanchang330022China National Engineering Research Center for Carbohydrate Synthesis/Key Lab of Fluorine and Silicon for Energy Materials and Chemistry of Ministry of Education Jiangxi Normal UniversityNanchang330022China Wenzhou Institute University of Chinese Academy of SciencesWenzhou325001China

For a polymer/polymer dismissible blend with two crystallizable components,the crystallization behavior of different components and the reciprocal influences between different crystals are interesting and important,but did not investigate in detail.In this study,the L-poly(lactic acid)/polypropylene(PLLA/PP)blends with different weight ratios were prepared by melt mixing and the crystallization behavior of the blends were investigated.Results showed that the crystalline structures of PLLA and PP were not altered by the composition.For the crystallization of PLLA,both the diffusion of chain segments and crystallization rate were enhanced under the existence of PP crystals.For the crystallization of PP,its crystallization rate was depressed under the existence of amorphous PLLA molecular chains.When the PP crystallized from the existence of PLLA crystals,although the diffusion rate of PP was reduced by PLLA crystals,the nucleation positions were obviously enhanced,which accelerated the formation of PP crystals.This investigation would supply more basic data for the application of PLLA/PP blend.

关键词： L-poly(lactic acid) Polypropylene blends Crystalization behavior Crystallization acceleration

Effects of nanofiller and voltage stabilizer on partial discharge resistance of polypropylene/elastomer blends:A comparison study

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High Voltage 2023年第2期8卷 251-261页

作者： Yu Gao Jing Li Xuri Xu Jinjing Peng Tao Han Boxue Du School of Electrical and Information Engineering Tianjin UniversityTianjinChina State Grid Yancheng Power Supply Company YanchengChina Guangzhou Panyu Power Supply Bureau Guangzhou Power Grid CorporationGuangzhouChina

This paper reports on the individual and synergistic influence mechanisms of nano-silica(SiO_(2))and voltage stabilizers on partial discharge(PD)resistance of polypropylene blended with ethylene-octene copolymer elastomer.The SiO_(2)nanoparticles and three types of voltage stabilizers,that is,benzoin,4,40-dimethoxybenzil,and 3-aminobenzoic acid are selected as fillers to prepare samples.PD is initiated in a rod-to-plane electrode system with an alternating current voltage of 5 kVrms.PD characteristics are captured with multi-sensors,and the erosion profile of the test sample is measured using a three-dimensional(3D)optical profilometer.Carrier trap distribution is extracted with isothermal surface potential decay measurement to assist the analysis of PD eroding material.Fourier transform infrared spectrum,scanning electron microscopy,X-ray diffraction spectrum,and differential scanning calorimetry analysis are performed to reveal the change in material structures caused by the fillers.Test results indicate that the PD resistance of the blend can be improved by the addition of nano-SiO_(2)and voltage stabilizers individually and synergistically.The PD resistance of PO is increased by 71.2%at most in the sample with 3 wt%nano-SiO_(2)addition.The sample filled with SiO_(2)exhibits better PD resistance than that with the voltage stabilizer or co-added,which should be ascribed to the introduction of deep traps,the formation of the packaged layer,the suppression of oxygen diffusion of the nanofillers,and the good compatibility between additives and the polymer matrix.

关键词： polypropylene synergistic blends

Highly insulating thermoplastic blends comprising a styrenic copolymer for direct‐current power cable insulation

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High Voltage 2022年第2期7卷 251-259页

作者： Yingwei Ouyang Amir Masoud Pourrahimi IdaÖstergren Marcus Mellqvist JakobÅnevall Azadeh Soroudi Anja Lund Xiangdong Xu Thomas Gkourmpis Per‐Ola Hagstrand Christian Müller Department of Chemistry and Chemical Engineering Chalmers University of TechnologyGöteborgSweden Department of Electrical Engineering Chalmers University of TechnologyGöteborgSweden Innovation&Technology Borealis ABStenungsundSweden

The impact of the composition of blends comprising low‐density polyethylene(LDPE),isotactic polypropylene(PP)and a styrenic copolymer additive on the thermomechanical properties as well as the direct‐current(DC)electrical and thermal conductivity is investigated.The presence of 5 weight percent(wt%)of the styrenic copolymer strongly reduces the amount of PP that is needed to enhance the storage modulus above the melting temperature of LDPE from 40 to 24 wt%.At the same time,the copolymer improves the consistency of the thermomechanical properties of the resulting ternary blends.While both the DC electrical and thermal conductivity strongly decrease with PP content,the addition of the styrenic copolymer appears to have little influence on either property.Evidently,PP in combination with small amounts of a styrenic copolymer not only allows to reinforce LDPE at elevated temperatures but also functions as an electrical conductivity‐reducing additive,which makes such thermoplastic ternary formulations possible candidates for the insulation of high‐voltage power cables.

关键词： property. blends copolymer

Temperature Effect on the Conformation Transition of Ultra-high Molecular Weight Polyethylene/Polypropylene blends Undergoing Continuous Volume Extensional Flow:A Mesoscopic Simulation

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Journal of Wuhan University of Technology(Materials Science) 2022年第3期37卷 540-545页

作者：王军霞 YAN Shilin 余丁山 Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education and Key Laboratory of High Performance Polymer-based Composites of Guangdong Province School of ChemistrySun Yat-Sen UniversityGuangzhou510275China Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics Wuhan University of TechnologyWuhan 430070China

Due to the multiformity and complexity of chain conformation under external flow and the challenge of systematically investigating the transient conformation and dynamic evolution process of polymer chains at the molecular level by means of present experimental techniques,a universal description of both chain conformation and dynamics with respect to continuous volume extensional flow(CVEF)is still absent.Taking into account the temperature effect,we performed dissipative particle dynamics(DPD)simulations with the particles corresponding to the repeat units of polymers over a wide temperature range and analyzed the correlation with the conformational properties of ultra-high molecular weight polyethylene/polypropylene(UHMWPE/PP)blend in response to the CVEF.With time evolution,the polymer chains become highly oriented parallel to the flow direction instead of the initial random coiling and self-aggregation.It is found that a high temperature is necessary for more substantial compactness to take place than low temperature.The low-k plateau and low-k peak in structure factor S(k)curves suggest a low degree of conformational diversity and a high degree of chain stretching.It is also concluded that the intra-molecular C-C bond interaction is the main driving force for the dynamics process of the chain conformations undergoing CVEF,where the motion of the alkyl chains is seriously restricted owing to the increase in bond interaction potential,resulting in a reduction of the difference in diffusion rates among alkyl chains.

关键词： temperature effect dissipative particle dynamics ultra-high molecular weight polyethylene polypropylene volume extensional flow chain conformation blends

Thermal, Mechanical and Electrical Studies of Novel Shape Memory Polyurethane/Polyaniline blends

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Chinese Journal of Polymer Science 2015年第9期33卷 1313-1324页

作者： Rabia Sattar Ayesha Kausar Muhammad Siddiq Department of Chemistry Quaid-i-Azam University Nanosciences and Catalysis Division National Centre for Physics Quaid-i-Azam University Campus

Shape memory polymer （SMP） blends based on polyurethane （PU） and polyaniline （PANI） were prepared via chemical in situ polymerization process. The thermal, mechanical, electrical and shape memory properties were investigated. The structural characterization and morphology of the polymer blends were inspected by Fourier transform infrared （FTIR） and scanning electron microscopy （SEM）, respectively. The 1 wt% of PANI loading enhanced the thermal stability of the system up to 339 ~C. According to differential scanning calorimetry （DSC）, the glass transition temperature （Tg） and melting temperature （Tm） of PU/PANI blends increased with the polyaniline loading （0.1 wt%-l wt%）. Improved mechanical properties such as tensile strength and Young＇s modulus of PU matrix were also observed with PANI. Moreover, the electrical conductivity of PU/PANI blends was also found to be a function of PANI loading. Remarkable recoverability of thermally triggered shape memory （SM） behavior to the extent of 96% was achieved for 1 wt% PANI blend.

关键词： Shape memory Polyurethane Polyaniline blends Conductivity.

The Influence of Trans-1,4-poly(butadiene-co-isoprene) Copolymer Rubbers(TBIR) with Different Molecular Weights on the NR/TBIR blends

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Chinese Journal of Polymer Science 2019年第10期37卷 966-973,I0003页

作者： Hao Wang Ri-Guo Wang Yun-Sheng Ma Bo Luan Ai-Hua He Shandong Provincial Key Laboratory of Olefin Catalysis and Polymerization Key Laboratory of Rubber-plastics(Ministry of Education)School of Polymer Science and EngineeringQingdao University of Science and TechnologyQingdao 266042China Shandong Huaju Polymer Material Co. Ltd.Binzhou 256500China

The molecular weight of a polymer is of prime importance and greatly influences the processing and mechanical properties of the polymer. Trans-1,4-poly(butadiene-co-isoprene) multi-block copolymer rubbers(TBIR) exhibit outstanding fatigue resistance, low heat build-up and good abrasion resistance, and are expected to be desirable candidate for high performance tire. Study on the influence of TBIR with different molecular weights on the structure and properties of TBIR and natural rubber(NR)/TBIR blends is essential to understand its contribution to the greatly improved dynamic properties of the rubber vulcanizates. TBIR with different molecular weights characterized by 1H-NMR, 13C-NMR, GPC, and DSC were highly trans-1,4-copolymers with similar chain sequence distribution and crystalline trans-1,4-polyisoprene(TPI) blocks. The green strength and modulus of TBIR increased with the increasing molecular weight.The NR/TBIR compounds filled with 40 phr carbon black were chemically cured by sulfur for the preparation of NR/TBIR vulcanizates.The compatibility between NR and TBIR, filler distribution, crosslinking bond and density, and properties of NR/TBIR vulcanizates were studied. The NR/TBIR vulcanizates showed increasing tensile strength, hardness, modulus, rebound, abrasion resistance, and flexural fatigue properties with increasing molecular weight of TBIR. Furthermore, they presented significant improvement in flexural fatigue resistance when compared with that of NR vulcanizate. The contribution mechanism of TBIR on the NR/TBIR blends was discussed. The TBIR with a wide range of molecular weight are ideal rubbers for high performance tires.

关键词： Trans-1,4-poly(butadiene-co-isoprene)copolymer rubber Nature rubber blends Molecular weight Fatigue resistance

MISCIBILITY AND MORPHOLOGY OF THIN FILMS OF blends OF POLYSTYRENE WITH BROMINATED POLYSTYRENES: EFFECTS OF VARYING THE MOLECULAR WEIGHT, BROMINATION DEGREE AND ANNEALING

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Chinese Journal of Polymer Science 2006年第5期24卷 515-528页

作者：宋锐 College of Material Science and Chemical Engineering Zhengzhou University of Light Industry Zhengzhou 450002 China College of Chemistry and Chemical Engineering Graduate University of Chinese Academy of Sciences Beijing 100039 China

Thin films of incompatible polymer blends can form a variety of structures during preparation and subsequent annealing process. For the polymer blend system consisting of polystyrene and poly（styrene-co-p-bromo-styrene）, i.e., PS/PBrxS, its compatibility could be adjusted by varying the degree of bromination and the molecular weight of both components comprised. In this paper, surface chemical compositions of the cast and the annealing films were investigated by X-ray photoelectron spectroscopy （XPS） and contact angle measurement; meanwhile, surface topographical changes are followed by atomic force microscopy （AFM）. In addition, substantial attention was paid to the effect of annealing on the morphologic variations induced by phase separation and/or dewetting of the thin film. Moreover, the influences of the molecular weight, Mw, as well as the brominated degree, x%, on the sample surface are explored systematically, and the corresponding observations are explained in virtue of the Flory-Huggins theory, along with the dewetting of the polymer thin film.

关键词： blends Thin film Annealing X-ray photoelectron spectroscopy.

THERMAL BEHAVIOR OF THERMOTROPIC HYDROXYETHYL CELLULOSE ACETATE/POLYETHYLENE blends

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Chinese Journal of Polymer Science 1997年第1期15卷 57-64页

作者：王海琳陈进明黄勇沈家瑞 Laboratory of Cellulose and Lignocellulosics Chemistry Guangzhou Institute of Chemistry Chinese Academy of Sciences Guangzhou 510650 Department of Polymer Materials Science and Engineering South China University of Technology Guangzhou 510641

The thermal behavior of thermotropic hydroxyethyl cellulose acetate (HECA)/polyethylene (PE) blends has been studied by DSC. It is found that the blends of HECA and PE are immiscible but the crystallization of PE is affected by HECA chains in the blends with more than 50% HECA, which results in the subordinate crystallization of PE and the formation of imperfect structures in the PE crystals. The imperfection of PE crystals in the blends can be eliminated after annealing at 393K.

关键词： hydroxyethyl cellulose acetate polyethylene blends thermal behavior polyethylene blends

Crystallization Kinetics and Morphology of Poly(vinylidene fluoride)/Poly(ethylene adipate) blends

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Chinese Journal of Polymer Science 2015年第2期33卷 349-361页

作者：王海军 Hui-ping Feng Xue-chuan Wang Qing-chuan Du Chao Yan Shaanxi University of Science and Technology Shaanxi Research Institute of Agricultural Products Processing Technology School of Material Science & Engineering Jiangsu University of Science and Technology

The miscibility, isothermal crystallization kinetics and morphology of the poly（vinylidene fluoride）（PVDF）/poly（ethylene adipate）（PEA） blends have been studied by differential scanning calorimetry（DSC）, optical microscopy（OM） and scanning electron microscopy（SEM）. A depression of the equilibrium melting point of PVDF was observed. From the melting point data of PVDF, a negative but quite small value of the interaction parameter ？PVDF-PEA is derived using the Flory-Huggins equation, implying that PVDF shows miscibility with PEA to some extent. Nonisothermal and isothermal crystallization kinetics suggest that the crystallization rate of PVDF decreases with increasing the amount of PEA, and a contrary trend was found when PEA crystallizes with the increase of the amount of PVDF. It was further disclosed that the blend ratio and crystallization temperature affect the texture of PVDF spherulites greatly, which determines the subsequent crystallization of PEA. At high temperatures, e.g. 150 ℃, the band spacing of PVDF spherulites increases with the addition of PEA content and the spherulitic structure becomes more open. In this case, spherulitic crystallization of PEA is not observed for all blend compositions. At low temperatures, e.g. 130 ℃, for the PEA-rich blends, the interpenetrated structures are eventually formed by the penetration of the spherulites of PEA growing within the pre-existing PVDF spherulites.

关键词： Crystallization Thermodynamic properties blends Poly（vinylidene fluoride） Poly（ethylene adipate）

Effects of Crystallization Temperature and Blend Ratio on the Crystal Structure of Poly(butylene adipate) in the Poly(butylene adipate)/Poly(butylene succinate) blends

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Chinese Journal of Polymer Science 2014年第4期32卷 488-496页

作者： Hai-jun Wang Hui-ping Feng 王学川 Pei-ying Guo Ting-shan Zhao Long-fang Ren Xi-huai Qiang Yu-hao Xiang 晏超 Key Laboratory of Chemistry and Technology for Light Chemical Industry Ministry of EducationShaanxi University of Science and Technology School of Material Science & Engineering Jiangsu University of Science and Technology

The effects of crystallization temperature and blend ratio on the polymorphic crystal structures of poly（butylene adipate）（PBA） in poly（butylene succinate）（PBS）/poly（butylene adipate）（PBS/PBA） blends were studied by means of differential scanning calorimetry （DSC）, wide-angle X-ray diffraction （XRD） and atomic force microscopy （AFM）. It was revealed that the polymorphism of PBA can be regulated by the blend ratio even in a non-isothermal crystallization process. The results demonstrate that high temperature favors fiat-on α crystals, while low temperature contributes to edge-on β crystals. It was also found that the effect of blend ratio on the crystallization mechanism of PBA is well coincident with that of the crystallization temperature. The increment of PBS content in the PBS/PBA blend gives rise to more β-form crystals of PBA. For those PBS/PBA blends with low PBA content, the interlamellar phase segregation of PBA makes its molecular chains so difficult to diffuse from one isolated microdomain to another that high crystallization temperature and sufficiently long crystallization time will be required if the PBA α-type crystals are targeted.

关键词： blends Crystallization Poly（butylene adipate） Poly（butylene succinate）.