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Science china chemistry 2018年第1期61卷 46-53页

作者： Guangcui Yuan charles c.han center for Neutron Research National Institute of Standards and Technology USA Department of Polymer Engineering The University of Akron Institute for Advanced Study Shenzhen University

Glass transition involves a many-body interaction and relaxation process. The splk of relaxation spectrum and the extremely slow dynamics bring into considerations of non-linearity and non-equilibrium. Some of our recent findings in two measurable colloidal systems are reviewed, one with a simple attractive interparticle potential and the other with a competitive （repulsive vs. attractive） inter-particle interaction. With an approach from interaction potential changes to the corresponding structural and relaxation responses, along the path of reaching the final equilibrium, we illustrate some interesting physics in glass formation process. Also, some reviews on the popular glass transition theories are made to remind readers to avoid artifacts and misinterpretations.

关键词： glass transition slow dynamics polymer colloid

SYNTHESIS OF EXFOLIATED ISOTAcTIc POLYPROPYLENE/FUNcTIONAL ALKYL-TRIPHENYLPHOSPHONIUM-MODIFIED cLAY NANOcOMPOSITES BY IN SITU POLYMERIZATION

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chinese Journal of Polymer Science 2013年第11期31卷 1501-1508页

作者： Kai Du 贺爱华 Fu-yong Bi charles c.han Fine chemicals Department Beijing Research Institute of Chemical IndustrySINOPEC State Key Laboratory of Polymer Physics and chemistry Joint Laboratory of Polymer Science and MaterialsBeijing National Laboratory for Molecular ScienceInstitute of ChemistryChinese Academy of Sciences Key Laboratory of Rubber-Plastics Ministry of Education/Shandong Provincial Key Laboratory of Rubber-PlasticsSchool of Polymer Science and EngineeringQingdao University of Science and Technology State Key Laboratory of Polymer Physics and chemistry Joint Laboratory of Polymer Science and MaterialsBeijingNational Laboratory for Molecular ScienceInstitute of ChemistryChinese Academy of Sciences

Diphenyl （4-hydroxyphenyl） hexadecyl phosphonium bromide （POH） -modified montmorillonite （POHMMT） was used to prepare a novel Tic14/Mgc12/POHMMT compound catalyst and exfoliated iPP/POHMMT nanocomposites were prepared by the in situ intercalative polymerization of propylene with the Tic14/Mgc12/POHMMT compound catalyst. The POH surfactants don＇t change the catalytic characteristic of the Z-N catalyst and the obtained PP presents high isotacticity, normal molecular weight and molecular weight distribution. The WAXD, SAXS and TEM results demonstrate the highly exfoliated iPP/POHMMT nanocomposites were produced by the in situ polymerization with this novel catalyst, while the intercalated iPP/Na＋MMT nanocomposites were produced with the Tic14/Mgc12/Na＋MMT compound catalyst. Through this approach, in situ propylene polymerization can actually take place between the silicate layers and lead not only to PP with high isotacticity and molecular weight, but also to highly exfoliated PP nanocomposites.

关键词： clay Nanocomposites Poly(propylene) (PP) Ziegler-Natta polymerization.

Phase Behavior Actuating Morphology and Rheological Response of Polybutadiene/Polyisoprene Blends under Small Amplitude Oscillatory Shear

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chinese Journal of Polymer Science 2014年第6期32卷 718-730页

作者： Fa-sheng Zou 董侠 Wei Liu Du-jin Wang charles c.han Beijing National Laboratory for Molecular Science CAS Key Laboratory of Engineering Plastics Joint Laboratory of Polymer Science and MaterialsInstitute of Chemistry Chinese Academy of Sciences

The morphology evolution and the corresponding linear viscoelastic behavior of the phase-separating polybutadiene （PB）/low vinyl content polyisoprene （LPI） blend have been investigated by phase contrast optical microscopy （PcOM）, small-angle light scattering （SALS） and rheometxy. Two kinds of structure evolutions and rheological responses have been observed. It is found that the co-continuous structure generally gives a power law behavior of the dynamic storage modulus versus frequency and the coarsening of co-continuous structure leads to a decrease of the storage modulus. For the droplet-matrix structure, a platform modulus is observed at the mediate frequencies, followed by the typical terminal relaxation behavior of storage modulus at the extremely low frequencies. The decreasing platform modulus and increasing terminal modulus with the growth of droplets are observed and can be well interpreted by the simplified Palieme model. The platform modulus and terminal modulus at a given frequency are found to be scalable with the phase separation time. Besides, the characteristic relaxation time and domain size of the droplets have been obtained by theology. And it seems that the theologically determined droplet dimensions are consistent with the ones determined by PcOM and SALS.

关键词： Phase separation Structure evolution Rheology.

The crystallization Behavior Regulating Nature of Hydrogen Bonds Interaction on Polyamide 6,6 by Poly(vinyl pyrrolidone)

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chinese Journal of Polymer Science 2023年第3期41卷 394-404,I0008页

作者： Yang Liu Li Peng Jie-Long Lin Yong Zhou Du-Jin Wang charles c.han Xian-Bo Huang Xia Dong National-certified Enterprise Technology center Kingfa Science and Technology Co.LTD.Guangzhou 510663China cAS Key Laboratory of Engineering Plastics Beijing National Laboratory for Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBejing 100190China University of chinese Academy of Sciences Beijing 100049China

The crystallization behavior of polyamide 6,6(PA66) under complex flow field is of great importance for its final mechanical ***(vinyl pyrrolidone)(PVP) was applied as crystallization modifying agency to improve processability of *** regulation nature on hydrogen bonds(H-bonds) interaction of PVP was studied upon cooling *** revealed by in situ FTIR,the sample with 5 wt% PVP displays decreased enthalpy change(ΔH) for both the generation of H-bonds and the transition of H-bonds from “disordered” to “ordered” state,which illustrates the molecular mechanism for the regulation of crystallzation ***,2D-WAXD is applied to reveal the evolution of microstructure for sample under external injection *** orientation factor(f_(H)) decreases obviously with the addition of PVP,because the relaxation of chain segments is promoted as well the crystallization is *** above crystallization and microstructure changes during the processing provokes the improvement of processability without the apparent sacrifice of mechanical properties.

关键词： Polyamide 66 Poly(vinyl pyrrolidone) Hydrogen bonds interaction

Evolution of Morphology and Structure During crystallization and Melting in Syndiotactic Polypropylene

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应用化学 2001年第5期18卷 280-288页

作者： Zhi-Gang WANG Benjamin S.HSIAO charles c.han State University of New York at Stony Brook Department of ChemistryStony BrookNY 11794-3400 Polymers Division and center for Neutron Research National Institute of Standards and TechnologyGaithersburgMD 20899

Structure and morphology development during isothermal crystallization and subsequent melting of syndiotactic polypropylene(sPP) was studied by time-resolved simultaneous small-angle X-ray scattering(SAXS) and wide-angle X-ray diffraction(WAXD) methods with synchrotron radiation and differential scanning calorimetry(DSc). The time and temperature dependent parameters such as long period, L , crystal lamellar thickness, l c, amorphous layer thickness, l a, scattering invariant, Q , crystallinity, X c, lateral crystal sizes, L 200 and L 020 , and unit cell parameters a and b were extracted from SAXS and WAXD profiles. Decreasing long period and crystal thickness indicate that thinner secondary crystal lamellae are formed. The decreases in unit cell parameters a and b during isothermal crystallization process suggest that crystal perfection takes place. The changes in the morphological parameters (the invariant, Q , crystallinity, X c, long period, L , and the crystal thickness, l c) during subsequent melting were found to follow a two-stage melting process, corresponding to the dual endotherm behavior in the DSc scan. We conclude that the dual melting peaks are due to the melting of secondary and primary lamellae(first peak) and the subsequent recrystallization-melting process(second peak). Additional minor endothermic peak located at the lowest temperature was also detected and might be related to melting of secondary, thinner and defective lamellae. WAXD showed that during melting, thermal expansion was greater along the b axis than that along the a axis.

关键词：间规聚丙烯结晶熔化晶体结构 DcS SAXS WAXD

Influence of Phase Separation and Shear on the crystallization of Polyolefin Blends

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Influence of Phase Separation and Shear on the Crystallizati...

第三届世界粘接及相关现象大会暨北京粘接学会第十五届学术年会

作者： charles c.han State Key Laboratory of Polymer Physics and chemistry Joint Laboratory of Polymer Science and Materials Institute of chemistry Chinese Academy of Sciences

The correlation between liquid-liquid phase separation(LLPS) and crystallization at several compositions in statistical copolymer blends of poly(ethylene-co-hexene)(PEH) and poly(ethylene-co-butene)(PEB) has been examined by optical microscopy(OM),atomic force microscopy(AFM) and differential scanning calorimetry (DSc).The overwhelming change in the crystallization kinetics due to the density fluctuation caused by the spontaneous spinodal LLPS is *** coupling mechanism suggests a new mechanism in the nucleation -crystallization *** evidences are pointing to a cross-over mechanism from the spinodal fluctuations

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Application of Light Scattering, Small Angle Neutron Scattering and X-ray Scattering in Polymer Research

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Application of Light Scattering, Small Angle Neutron Scatter...

第三届散裂中子源多学科应用研讨会

作者： charles c．han Institute of chemistry Chinese Academy of Sciences Beijing China

＜正＞Similarities and differences among light scattering, small angle neutron scattering, and x-ray scattering for polymer research will be briefly discussed. Some applications of these three techniques in polymer re...

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Nascent Morphology of In-reactor Polyolefin Blends and the Influence of Phase Separation on the crystallization Morphology

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Nascent Morphology of In-reactor Polyolefin Blends and the I...

2010年全国高分子材料科学与工程研讨会

作者： charles c.han Joint Laboratory of Polymer Science and Materials Institute of ChemistryChinese Academy of Sciences

＜正＞Due to the cost advantage and the recycle/re-use potential,polyolefin blends/alloys have become the largest group of commodity plastics,and have the potential to replace the market of many traditional engineering *** the other hand,these polymers with the simplest chemical structures have brought many challenges in chemistry and in physics in order to develop further technological

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Synthesis and characterization of ABA Type Fluorine containing Polyurethane copolymers

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Synthesis and Characterization of ABA Type Fluorine Containi...

2007年全国高分子学术论文报告会

作者： charles c．han Beijing National Laboratory for Molecular Sciences Joint Laboratory of Polymer Science and Materials State Key Laboratory of Polymer Physics and ChemistryInstitute of ChemistryCASBeijing 100080China

＜正＞ABA type fluorine containing polyurethane block copolymersd（FPU）were synthesized from 4,4′-methylene-bis-（phenylisocyanate）,polytetrahydrofuran（Mn= 2000）and monofunctional perfluoropolyether alcohol using... 详细信息

关键词： fluorine polyurethanes XPS contact angle hydrophobic

Electrospun Fibers of Fluorine containing Polyurethane

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Electrospun Fibers of Fluorine Containing Polyurethane

2007年全国高分子学术论文报告会

＜正＞Electrospinning is a novel and efficient method that can be utilized to form polymer *** containing polyurethanes possess tuning flexibility,excellent elongation and ***,they can present low surface *** non-woven fiber mats were prepared from the fluorine containing polyurethanes using a THF *** fibers range from 2 to 4 micrometers in *** surface of the fibers mat represents good hydrophobic *** water contact angle with a 5.0μL water droplet on the surface is in the range of 142～147°.The mats show well elongation. No breaking of fibers was found even if the fibers were stretched with diameter shrank to one third of *** fibers could almost get back to original state when the force was *** mats can be rolled easily.

关键词： electrospun fiber fluorine polyurethanes hydrophobic