聚苯乙烯／等规聚丙烯共混中双重海／岛复合结构的形成

 从理论上详细分析了非相容共混体系液滴形变、破碎的机理和双重海／岛复合结构的形成条件．应用电子显微镜和光学显微镜法，以聚苯乙烯／等规聚丙烯共混物为试样，对聚合物共混中双重海／岛复合结构的形成机理、结构形态和形成条件进行了研究．提出了双重海／岛复合结构形成过程的模型．     

LDPE／CPE／炭黑三相复合导电体系的亚微形态和导电性能

对ＬＤＰＥ／ＣＰＥ／炭黑三相复合导电体系的亚微形态和导电性能进行了研究。实验发现,该体系的亚微形态在共混比ＬＤＰＥ／ＣＰＥ大于和小于５０／５０时为典型的“海－岛”结构,在５０／５０时,为两相连续交错“互锁”结构;在共混比大于５０／５０时,ＬＤＰＥ／ＣＰＥ炭黑复合体系的导电性能较单一的ＬＰＤＰＥ树脂与炭黑复合体系的高２－５个数量级。     

PBT／PC共混体系流变性能与形态结构研究

采用毛细管流交仪测定了ＰＢＴ／ＰＣ共混物的表观粘度、剪切应力，观察了不同共混物组成和不同温度下共混物的流变行为，并借助扫描电镜对共混物和微观形态结构进行分析。结果表明：ＰＢＴ／ＰＣ熔体共混物的流变行为接近假塑性流体．温度对共混物的流变行为影响很大，共混物的熔体粘度在ＰＢＴ／ＰＣ为９０／１０和６０／４０时呈双极值．共混物为两相结构，ＰＣ含量为４－５０％时呈两互锁结构。     

热致液晶／PEEK／嵌段共聚物共混体系的结构与性能

用ＷＡＸＤ、ＳＥＭ及力学性能测试等研究热致液晶／ＰＥＥＫ／嵌段共聚物三元共混体系形态、结构和性能。结果表明嵌段共聚物的加入，使体系具有一定的相容性和较好的界面粘接，共混物的强度、模量有一定的提高，对共混物的结晶行为具有明显的影响，当热致液晶含量高时，基材与液晶两相间出现明显的分离现象，即“皮－芯”结构．     

聚苯乙烯/顺丁橡胶共混过程中的相结构

利用激光背散射装置结合密炼机对聚合物共混过程进行了在线分析．以典型完全不相容体系聚苯乙烯／顺丁橡胶为共混体系，对不同共混速度下结构参数随共混时间及共混条件如剪切速率等的变化进行了详细讨论．利用扫描电镜与激光背散射在线分析对聚合物共混过程结构参数变化进行了比较，结果显示聚苯乙烯／顺丁橡胶共混物处于熔融态与处于固态时结构基本相同．     

核／壳结构增韧剂对环氧树脂的抗冲改性

核／壳结构增韧剂对环氧树脂的抗冲改性张明耀，张会轩，杨海东，冯之榴（吉林工学院化学工程系长春１３００１２）（中国科学院长春应用化学研究所长春）关键词核／壳结构，增韧剂，环氧树脂，共混核／壳结构增韧剂是用分步乳液聚合技术制造的一种复合乳胶粒子，其核为橡...     

聚苯乙烯／顺丁橡胶接枝苯乙烯共混过程光散射研究

聚合物共混物共混过程结构发展的研究较多［’－‘j，一致结论是分散相尺寸的迅速降低主要发生在最初1．5min到2min．当材料处于熔融或软化过程时，结构将发生极大的变化．材料在共混中往往出现薄片状或带状结构，基本处于微米尺度．本文利用X光小角散射、激光背散射及扫描电镜分别从微米尺度和纳米尺度对共混过程中微观结构的动态变迁进行了讨论聚苯乙烯（PS，民一5．8X10’，风一2．7XIO5，密度1．05，北京燕山石化公司生产）与顺丁橡胶接枝苯乙烯（PCBR－g－St，本实验室采用溶液接枝合成，接技率7．l％）按照80／20（质量比）比例…     

相界面张力对两相聚合物熔体中分散相粒子粗化速度的影响研究

多相高分子共混物熔体中微区的发展机理,决定着体系的最终相结构．所以研究共混物熔体或溶液中的微区聚结机理已越来越显得重要和必要．作者先前的研究工作表明［１～６］,通过简单共混得到的均匀共混体系（如ＰＰ／ＥＶＡｃ）,在一定的退火热处理条件下,会自组织形成梯度相结构,即分散相粒子尺寸及其浓度从样品中心到表面逐渐增大．作者认为,这一结构的形成主要与基板对共混体系粗化过程的影响作用有关．初步认为是由于体系分散相聚结过程中,共混组分对基板的选择性浸润析出而导致了这种特殊的结构,亦可称为基板诱导相结构的形成．…     

聚丙烯／氯化聚乙烯共混物的形态结构

 用透射电子显微镜方法研究了聚丙烯（ｉＰＰ）和氯化聚乙烯（ＣＰＥ）共混物溶液浇铸膜的形态结构．共混物中ＣＰＥ含量≤７０％时不妨碍ｉＰＰ球晶两种结构（交叉结构和条状结构）区域的生成．在ＣＰＥ含量≥８０％时，分散相ｉＰＰ形成近乎直角（８０°）交叉的稀疏的片晶网络．在共混物的全组成范围内，ＣＰＥ结晶在ｉＰＰ片晶上附生生长，二者结晶Ｃ轴的交角为５０°     

聚丙烯／氯化聚乙烯共混物的形态结构

用透射电子显微镜方法研究了聚丙烯（ｉＰＰ）和氯化聚乙烯（ＣＰＥ）共混物溶液浇铸膜的形态结构．共混物中ＣＰＥ含量≤７０％时不妨碍ｉＰＰ球晶两种结构（交叉结构和条状结构）区域的生成．在ＣＰＥ含量≥８０％时，分散相ｉＰＰ形成近乎直角（８０°）交叉的稀疏的片晶网络．在共混物的全组成范围内，ＣＰＥ结晶在ｉＰＰ片晶上附生生长，二者结晶Ｃ轴的交角为５０°     

Largely improved toughness of poly(lactic acid) by unique electrospun fiber network structure of thermoplastic polyurethane

Oriented thermoplastic polyurethane (TPU) fiber and fiber network were first prepared by electrospinning. The as-prepared TPU fiber or fiber network was then pre-fixed in poly(lactic acid) (PLA)/TPU composite to improve the toughness of PLA. For comparison purpose, TPU/PLA composites with sea-island morphology were also prepared by traditional solution blending and mechanical blending. The results show that the toughness of PLA is greatly increased by the special pre-fixed oriented TPU fibers even at a low content, and the toughness is further increased by the TPU fiber network. Our results indicate for the first time that the toughening effect of special TPU fibers or fiber network is much better than that of traditional TPU with sea-island morphology. This study provides guidance to largely improve the toughness of PLA by designing the special phase morphology of TPU.     

Progress in preparation,characterization, surface functional modification of graphene oxide: A review

Graphene oxide (GO) has become the focus of scientific research due to unique mechanical, optical, electrical and chemical properties. We review the synthesis approaches and formation mechanism of GO, and propose that the crucial factor to the preparation of GO is to find efficient and environmentally friendly oxidant. Various characterization techniques are introduced, and characteristics are summarized. The GO model theories are synopsized, and determining the structure of GO has important influence on its surface modification and its application and development in composite materials. The interaction and reaction types between GO matrix and modified molecules, as well as the properties of modified products were described. In conclusion, the present challenges and future research directions are presented in terms of preparation and surface functional modification for GO.     

Improvement in Toughness of Polylactide by Melt Blending with Bio-based Poly（ester）urethane

Polylactide （PLA） was successfully toughened by blending with bio-based poly（ester）urethane （TPU） elastomers which contained bio-based polyester soft segments synthesized from biomass diols and diacids. The miscibility, mechanical properties, phase morphology and toughening mechanism of the blend were investigated. Both DSC and DMTA results manifested that the addition of TPU elastomer not only accelerated the crystallization rate, but also increased the final degree of crystallinity, which proved that TPU has limited miscibility with PLA and has functioned as a plasticizer. All the blend samples showed distinct phase separation phenomenon with sea-island structure under SEM observation and the rubber particle size in the PLA matrix increased with the increased contents of TPU. The mechanical property variation of PLA/TPU blends could be quantitatively explained by Wu＇s model. With the variation of TPU, a brittle-ductile transition has been observed for the TPU/PLA blends. When these blends were under tensile stress conditions, the TPU particles could be debonded from the PLA matrix and the blends showed a high ability to induce large area plastic deformation before break, which was important for the dissipation of the breaking energy. Such mechanism was demonstrated by tensile tests and scanning electron microcopy （SEM） observations.     

具有包藏结构的三元聚丙烯纳米复合材料结构与性能关系的研究

制备了一种新型聚丙烯 丁苯橡胶 纳米碳酸钙三元纳米复合材料 .研究结果显示 ,复合材料中的大多数纳米碳酸钙粒子被包藏在丁苯橡胶中 ,并与之共同形成分散于聚丙烯树脂中的分散相 ,这种聚丙烯纳米复合材料具有高刚性、高韧性、高耐热性和高的结晶速率 .系统研究了成核剂苯甲酸钠的加入和纳米碳酸钙的用量对该类纳米复合材料相态结构、结晶形态和结晶动力学的影响 ,以及具有包藏结构的分散相粒径和PP中β晶含量对材料性能的影响 .结果表明 ,苯甲酸钠的加入和纳米碳酸钙用量的提高均可使体系中分散相粒径减小 ,结晶速率加快 ,进而使材料的韧性、刚性和耐热性提高 .     

Improving breakdown strength and energy storage efficiency of poly(vinylidene fluoride-co-chlorotrifluoroethylene) and polyurea blend films by double layer structure design

All-organic composites are widely used in energy storage application due to the high breakdown strength performance, but the improvement of energy storage was limited by the relatively low dielectric constant. Therefore, to satisfy the high demands of dielectric materials, energy storage properties of polymer composites should be further enhanced. In this article, poly(vinylidene fluoride-co-chlorotrifluoroethylene) (P(VDF-CTFE)) and polyurea (PUA), which are known as high dielectric ferroelectric material and linearly high energy storage efficiency material respectively, are composited through double layer (DL) casting method for the first time. The properties of DL structured composite film is contrasted with solution blending structure especially in energy storage efficiency, and the results demonstrate that DL structure design can make great use of advantages of two materials and also can avoid the influence of phase separation between P(VDF-CTFE) and PUA efficiently. Moreover, high breakdown strength (6180 kV/cm) and high energy storage efficiency (77%) of DL composites can be realized simultaneously by incorporating PUA as an insulating layer, and the mechanism is discussed in detail. This work provides an effective route to improve the energy storage properties of polymer dielectric materials and shows great application potential.     

SPHERULITIC STRUCTURE AND MORPHOLOGY OF POLY(ETHYLENE SUCCINATE)/POLY(ETHYLENE OXIDE) (PES/PEO) BLENDS WITH ONE-STEP CRYSTALLIZATION

The spherulitic structure and morphology development of poly(ethylene succinate)/poly(ethylene oxide) (PES/PEO) blends with one-step crystallization behavior were observed by means of polarizing optical microscope.It was found that the pure PES spherulite in which the adequate quantity of PEO melt existed in the interlamellar regions,and the blending spherulite formed by both PES and PEO lamellae could form simultaneously.When the two types of spherulites contacted with each other the front of the blendi...     

Insights into the surface property and blood compatibility of polyethersulfone/polyvinylpyrrolidone composite membranes: toward high‐performance hemodialyzer

Applications of blood purification membranes are fuelled by diverse clinical needs, such as hemodialysis, hemodiafiltration, hemofiltration, plasmapheresis, and plasma collection. For clinical usage, the adding of polyvinylpyrrolidone (PVP) is the general protocol for the design of antifouling and antithrombotic properties integrated artificial membranes. In the present work, to insight into the detailed surface properties and blood compatibilities of the PVP blended composite membranes, we synthesized a series of PVP polymers with different molecular weights using reversible addition fragmentation chain transfer polymerization and designed a series of polyethersulfone (PES)/PVP composite membranes by a physically blending method. The effects of PVP molecular weights and blending ratios on the surface properties and the blood compatibilities of the composite membranes were investigated in detail. The surface attenuated total reflection Fourier transform infrared spectra and scanning electron microscopy pictures indicated that the PVP was successfully immobilized into the membranes, and the composite membranes exhibited morphology transformation from finger‐like structure to sponge‐like structure, which indicated that the composite membrane had tunable porosity and permeability by adding PVP. The blood compatible tests revealed that the composite membranes showed increased hydrophilicity, decreased plasma protein adsorption, suppressed platelet adhesion, and prolonged blood clotting time compared with pristine PES membrane. These results indicated that the PES/PVP composite membranes exhibited enhanced antifouling and antithrombotic properties than the pristine PES membrane. Meanwhile, the results also suggested that the composite membranes with larger molecular weight PVP and higher blending ratios might show better blood compatibility. Copyright © 2014 John Wiley & Sons, Ltd.     

Hydrothermal Synthesis of Porous Al2O3/Al Metal Ceramics: IV. Synthesis of Composite Porous Ceramics in the Presence of Microporous and Mesoporous Adsorbents

The formation of the structure and properties of mesoporous composite ceramics based on an ASD-1 aluminum powder and commercial adsorbent powders (zeolites and active alumina) was studied. It was found that the mechanism of the formation of contacts between the particles of commercial adsorbents and aluminum is analogous to the mechanism of synthesis of an Al(OH)₃/Al composite. The dissolution of aluminum and the precipitation of the hydroxo complexes of aluminum from solution to the region of interparticle contacts are responsible for this mechanism. The resulting composite ceramics exhibited a polydisperse pore structure and high values of mechanical strength, gas permeability, and thermal conductivity; it can be used as a block adsorbent and catalyst support.     

聚合物多相复合体系的结构和内耗行为特征

描述了聚合物共混物及纤维增强聚合物基复合体系的内耗研究现状，并着重分析了内耗行为与微观结构的相关性。目前迫切需要解决的问题包括对内耗微观机制的研究，建立起适当的模型，并赋予特征参数以明确的物理意义。