高分子共混物及嵌段共聚物熔体的流变性 (Ⅱ)共混物熔体的弹性

综述了高聚物共混物熔体在流动过程中的弹性特征及规律，对不同共混物的弹性行为进行了归纳分类。发现相容性共混物体系的弹性随组成的变化是单调增减的，不相容共混物体系的弹性组成变化有几种情况：共混物的弹性参数介于两纯组分之间、共混物弹性出现最大或（和）最小值，以及弹性变化趋势和粘度变化趋势一致     

高聚物共混物及嵌段共聚物熔体的流变性

综述了高聚物二元共混物及嵌段共聚物熔体的静态流变性，分析了不同共混体系的流动曲线，总结了共混物的流动特性及规律。     

高分子共混物及嵌段共聚的溶体的流变性：（Ⅱ）共混物熔 …

综述了高聚物共混物溶体在流动过程中的弹性特性及规律，及不同共混物的弹性行为进行了归纳分类。发现相容性共混物体系的弹性随组成的变化是单调增减的，不相容共混物体系的弹性组成变化有几种情况：共混物的弹性参数介于两纯组分之间、共混物弹性出现最大或（或）最小值，以及弹性变化趋势和粘度变化趋势一致。     

云母/聚丙烯共混物熔体的拉伸流变性能

采用双料筒毛细管流变仪和Haul-off牵伸设备, 研究了云母(Mica)/聚丙烯(PP)共混物在拉伸流场中的流变性能。结果表明: Mica/PP共混物熔体拉伸流动属于拉伸变稀型, 随着云母含量的增加, 熔体的表观拉伸黏度逐渐增大。熔体的拉伸应力和表观拉伸黏度均随温度的升高而下降。随着拉伸应变速率的提高, 熔体的拉伸应力增大, 表观拉伸黏度减小, 熔体拉伸流动活化能呈下降趋势。云母微粒的加入使聚丙烯熔体的拉伸模量明显增大, 但随着拉伸速度的提高, 共混熔体的拉伸模量下降显著。为了提高Mica/PP共混物的纺丝稳定性, 应严格控制好拉伸速度和加工温度。     

聚合物共混物的反应性增容及相形态控制

综述了聚合物共混物的反应性增容及相形态控制的研究现状。介绍了聚合物共混物反应性增容的几种方法及增容机理,并从热力学、动力学和熔融共混过程中流动参数三方面对聚合物共混物相形态结构的控制进行了说明。     

聚酰亚胺及其共混物

本文综述了聚酰亚胺及其共混物的研究进展，讨论了聚酰亚胺的分子结构对其共混物的相容性。结晶行为及力学性能的影响。     

熔体的粘性和弹性对LDPE／PS共混物形态的影响

研究了粘性和弹性对低密度聚乙烯／聚苯乙烯共混物形态的影响。结果表明，不相容聚合物在均匀剪切流动中的分散程度以及分散相的形状与组分的粘度比、相对弹性和体积分数有关。当分散相的粘性和弹性较基相大得多时，随分散相的体积分数增加，球状的液滴形成葡萄串状。若两组分的粘性和弹性相当，在适中的混合比下，分散相产生高度变形。不管组分的粘反比和弹性比大小，若分散相的体积分数非常低，共混物的主要形态皆为分散相的球状液滴分散在基体中。     

PEK－C、LCP及其共混物的流动性能

研究了含酚酞聚苯醚酮（ＰＥＫ－Ｃ）、液晶聚合物（ＬＣＰ）及其共混物的流动性能，测定了ηａ－γ曲线及流动活化能（△Ｅ）。结果表明，（１）ＰＥＫ－Ｃ、ＬＣＰ及其共混物均属假塑性流体；（２）ＬＣＰ可增加ＰＥＫ－Ｃ的流动性；（３）它们的粘度均随温度的升高而降低；（４）共混物的△Ｅ随ＬＣＰ含量的增加而下降。     

PEK—C,LCP及其共混物的流动性能

研究了含酚酞聚苯醚酮（ＰＥＫ－Ｃ）、液晶聚合物（ＬＣＰ）及其共混物的流动性能，测定了ηａ－γ曲线及流动活化能（△Ｅ）。结果表明，（１）ＰＥＫ－Ｃ、ＬＣＰ及其共混物均属假塑性流体；（２）ＬＣＰ可增加ＰＥＫ－Ｃ的流动性；（３）它们的粘度均随温度的升高而降低；（４）共混物的△Ｅ随ＬＣＰ含量的增加而下降。     

聚醚醚酮及其共混物的研究EI

综述了高性能树脂聚醚醚酮及其共混物的研究现状，讨论了聚醚醚酮的形态结构、结晶和熔融双峰行为及力学性能的研究，指出了共混物的分子结构对相容性、形态结构及力学性能的影响，说明共混使所得高分子材料的性能更多样化。     

miPP/ziPP共混体系的流动性能

首次对茂金属聚丙烯(miPP)／齐格勒-纳塔聚丙烯(ziPP)共混体系的流动性进行了系统的研究。研究发现，在miPP／ziPP共混体系中，miPP含量的变化改变了共混体系的相结构，这种相结构会随着温度和剪切速率的变化而产生明显的变化，从而改变了体系的流动性能，且该共混体系在不同剪切速率下的流动曲线可以分别通过两个模型进行模拟。     

EPDM／PA高性能弹性体的某些性能研究

研究了EPDM/PA共混物的流变性能，耐油性、耐化学溶剂性、吸水性及动态生热。结果表明，随PA用量增多，共混物的假塑性变得不明显，呈现出宾汉流体的行为；共混物的表观粘度随剪切速率的增加而降低，表现出假塑性；PA分散于基体EPDM中，大幅度提高了基体的耐油性；虽然PA难溶于二甲苯；但共混物中的PA易于被二甲苯刻蚀；尽管共混物含30份的PA，但仍具有优良的耐吸水性，与近似硬度的EPDM过氧化物硫化胶相比，共混物的生热有大幅度降低。     

PP/POE共混物的毛细管和转矩流变行为

利用高压双管毛细管流变仪和Haake转矩流变仪研究了聚丙烯(PP)/乙烯-辛烯共聚物(POE)体系的流变行为,探讨了转速、剪切速率、温度及共混物的组成对熔体流变行为的影响。结果表明,两种方法所测得的熔体流变学结果基本一致,共混物熔体表现为假塑性流变行为。随着POE含量的增加,PP/POE共混物熔体的表观黏度和非牛顿指数表现为负偏差行为,粘流活化能则表现出正负偏差行为,说明PP与POE之间存在一定的相容性。     

正应力支配下混合顺序对PA6/HDPE/CNTs体系结构及性能的影响EI北大核心CSCD

利用自行研制的叶片式混炼装置,实现了正应力支配下聚合物复合体系的熔融共混。实验研究了混合顺序以及混合时间对高密度聚乙烯(HDPE)/尼龙6(PA6)/碳纳米管(CNTs)共混物的微观结构、流变特性、热性能及宏观力学性能的影响。结果表明:正应力支配作用能在短混合时间内实现PA6粒子和CNTs的均匀分散,分散效率高;相比于将HDPE,PA6,CNTs三者同时共混或者是先将PA6与CNTs混炼制成母料,再与HDPE共混这两种混合顺序,先将HDPE与CNTs混炼制成母料,再与PA6共混制得的共混物中分散相PA6粒径最小,分散更均匀,共混物的热性能以及力学性能更好。     

Melt blend studies of nanoclay-filled polypropylene (PP)–high-density polyethylene (HDPE) composites

The objective of this work is to study how the rheological factors of unfilled and nanoclay-filled HDPE–PP blend series influence the structure, morphology, and mixing characteristics. For this study, a series of HDPE–PP blends (0–100 wt % HDPE), with and without nanoclay, was prepared by using melt-mixing method. Nanoclay was varied from 0 to 5 wt % in all the blend and polymer series. The rheological properties were examined by melt viscosity, scanning electron microscopy, and theory of mixing. The result indicated that the viscosity of the blend increased as HDPE and nanoclay content increased, and also affected the structure and morphology of the resulting blend. The thermal properties were examined by using differential scanning calorimetry and suggest improved crystalline and melting characteristics of PP and PP-rich phase of blend. The structure of nanoclay-filled blend was examined by X-ray diffraction and transmission electron microscopy, confirming the formation of nanocomposite with improved tensile properties.     

Correlation Between Miscibility and Rheological Characteristics of the Polystyrene (PS) and Poly(styrene-co-acrylonitrile) (PSAN) Blends

Rheological measurement has been an effective technique to characterize the miscibility of polymer blends. This article investigates the viscoelastic behavior of poly(styrene) (PS) and poly(styrene-co-acrylonitrile) (PSAN) binary solutions in tetrahydrofuran (THF) relative to PS/PSAN/THF ternary solutions mainly reporting the findings of the authors involving the correlation between the miscibility and rheological behavior. Rheological properties, such as shear viscosity, and shear stress as a function of shear rate were investigated for different blend compositions. Moreover, complex viscosity, loss and storage moduli were also investigated as functions of both the frequency and blend composition. The criterion of miscibility based on the rule of mixture has been discussed. The present study revealed very small window of miscibility as only composition, 50/50 showed values close to the additivity rule or intermediate to those of the neat polymers, thereby indicating very weak interactions between the blend components. On the basis of various findings during the rheological investigation, the blend under study is classified almost immiscible. Moreover, the obtained results also suggested that the miscibility depends on the blend composition and frequency.     

Organoclay-modified thermotropic liquid crystalline polymers as viscosity reduction agents for high molecular mass polyethylene

Small amounts of organoclays of different sizes and concentrations were added into thermotropic liquid crystalline polymer (TLCP) forming four types of organoclay-modified TLCPs (TC3 white, TC3 dark, TC3 FS, and TC3 UP), which had different rheological behaviors in the nematic temperature region of TLCP. Acting as viscosity reduction agents, 1.0 wt% of each organoclay-modified TLCPs were blended with high molecular mass polyethylene (HMMPE), respectively. The organoclay-modified TLCP/HMMPE blends displayed different rheological properties from each other or compared with HMMPE and 1.0 wt% TLCP/HMMPE blend [PT1]. The organoclay-modified TLCPs had greater viscosity reduction efficiency than the original TLCP in HMMPE, a lower yielding stress and yielding start shear rate, and a narrower yielding transition region than those of PT1. The rheological performance of the blends, 1.0 wt% TC3 white/HMMPE, 1.0 wt% TC3 FS/HMMPE, and PT1, could be successfully described by a binary flow pattern model.     

Phase separation of polystyrene/poly(vinylmethylether)/organoclay nanocomposites

The effect of addition of organically modified montmorillonite (OMMT) on the phase separation of polystyrene (PS)/poly(vinyl methyl ether) (PVME) blend was examined. Using two types of OMMT modified with two different kinds of surfactants, the effect of organic modification on nanocomposites was investigated by focusing on three major aspects: phase transition, morphological study, and melt rheological behavior both below and above the critical transition temperature. X-ray diffraction (XRD) patterns revealed the formation of intercalated nanocomposites and transmission electron micrographic (TEM) observations showed that the ordering of silicate layers in blend matrix is well matched with the XRD patterns. The addition of clay was found to affect both the mechanism of phase separation and the final morphology. Such effects resulted in uncommon rheological behavior of the blend both below and above the critical transition temperature. Surface phase separation of thin films for virgin blend and nanocomposites was also examined by atomic force microscopy (AFM). Morphology resulting after phase separation was found to be dependent on the nature and the amount of OMMT added to the polymer blend.     

易水解聚酯的流变性能

合成了一系列易水解聚酯(EHDPET),研究了第三、四单体含量及添加剂B对EHDPET流变性能的影响,得到了EHDPET的粘流活化能与剪切速率之间的关系。结果表明,EHDPET的流动性能随第三单体(SIPE)含量的增加而下降,增大第四单体(脂肪族化合物A)的添加量和添加聚合物B均可使EHDPET的流动性能得到改善。