热致液晶聚合物／热塑性聚合物原位复合材料研究进展

综述了热致液晶聚合物／热塑性聚合物(TLCP／TP)原位复合材料的最新进展，系统阐述了TLCP／TP体系的微纤形成、流变行为、微观形态和力学性能，并对改善相容性和优化加工条件的研究工作作了具体介绍。     

聚合物原位复合材料研究进展

以热致液晶聚合物(TLCP)/热塑性聚合物(TP)原位复合体系为例,论述了原位复合材料的最新发展,对原位复合材料的相容性、流变性、形态、及力学性能等作了描述。     

TLCP／PC原位复合材料再加工能力的研究

热致液晶聚合物(TLCP)原位复合材料,具有优异的加工性能、力学性能和再加工能力。本文研究了热致液晶聚合物KU9221和聚碳酸酯(PC)原位复合材料的再加工能力。     

热致液晶高分子原位增强热塑性树脂复合材料研究进展

综述了热致液晶聚合物(TLCP)增强热塑性树脂(TP)原位复合材料的研究近况,主要讨论了TLCP／TP的增强机理,加工流变学特点,原位复合材料的界面相容性、结构特征与材料性能的关系,评述了多元共混和原位混杂增强复合材料。     

聚丙烯/热致性液晶聚合物原位复合材料的研究进展

聚丙烯是一个通用塑料,为了提高聚丙烯的性能,拓宽其应用领域,人们对聚丙烯进行了改性研究.笔者简述了热致液晶聚合物原位复合改性聚丙烯的研究进展,并讨论热致液晶聚合物对聚丙烯结晶与熔融行为、微观结构、流变性及力学性能的影响,介绍了改进TLCP与PP之间相容性的常用方法.最后对TLCP/PP原位复合材料的发展提出一些看法.     

热致液晶聚合物原位增强复合材料的研究

本文对热致液晶聚合物及其原位复合材料的研究进展和前沿问题作了详细评述。     

原位成纤复合材料研究进展

综述了近年原位成纤技术在热致性液晶聚合物(TLCP)/热塑性聚合物(TP)、TP/TP体系中的应用研究进展,提出目前研究过程中存在的问题及解决方法构想,展望原位成纤技术在新的复合体系中的的应用.     

液晶聚合物/聚酰胺复合体系的研究进展

综述了液晶聚合物与聚酰胺（PA）复合体系的研究进展,评述了溶致液晶聚酰胺/PA复合体系、热致液晶聚酯/PA复合体系、热致液晶聚酰胺/PA复合体系的各自特点以及影响液晶聚合物与树脂基体间相容性的因素,重点论述了改善热致液晶聚合物/PA组分间相容性的方法及其对材料最终力学性能的影响,指出利用分子间氢键提高热致液晶聚合物/PA相容性的优势,热致液晶聚酰胺增强PA树脂基体将有望成为PA增强改性的新方法。     

热致液晶聚合物增强PP/mPE原位复合材料的研究

采用热致液晶聚合物（TLCP）对PP及PP/mPE共混物进行增强，制得PP／TLCP和PP／mPE／TLCP原位复合材料。探讨了TLCP对复合材料拉伸性能、低温冲击性能和加工流变行为的影响。结果表明，加入15％的TLCP可以显著提高PP和PP／mPE的刚性，改善加工流动性。但由于体系的相容性较差，基体的拉伸强度有所降低，低温冲击韧性也有显著的降低。     

高性能聚合物共混改性的研究进展

对近几年国外对几种高性能聚合物材料与热致液晶聚合物共混体系的研究情况作了综述。详细了这些共混体系的流变性、形态及力学性能。对这些性能之间的内在联系也作了探讨说明。从这些体系的性能可以看出，少量的热致液晶聚合物可以作高性能热塑性塑料的加工助剂。     

PPS/TLCP共混体系结构与流变研究

采用热致液晶聚合物（TLCP）与聚苯硫醚（PPS）熔融共混的方式制备了PPS／TLCP复合材料，研究了PPS／TLCP共混体系的形貌、流变性能以及加工参数对微纤形成的影响。结果表明：TLCP可明显改善体系的加工特性，并能原位生成微纤化复合材料，TLCP对体系黏度有较大影响，在低剪切速率区黏度下降幅度较大，在高剪切速率区，黏度降低幅度小。PPS／TLCP复合材料存在皮芯结构，工艺参数对TLCP微纤的形成起着重要作用，通过提高注塑速度，对TLCP微纤的形成特别有利。     

PA66／TLCP原位复合材料的热性能、形貌及力学性能研究

通过挤出和注射成型制备了聚酰胺66／热致液晶聚酰胺（PA66／FLCP）原位复合材料，研究了其热性能、形貌及力学性能。DSC分析表明，PA66和TLCP相容性较好，随着TLCP含量的增加，PA66的结晶度、结晶速率下降；SEM分析表明，TLCP在PA66基体中分散均匀，两相相容性较好，当加入10％（质量分数，下同）的TLCP时，TLCP形成长径比比较大的纤维；拉伸试验结果表明，当加入TLCP后，PA66的力学性能有明显的改善。当加入10％的TLCP时，共混物的力学性能增幅最大，拉伸强度增加79．6％，拉伸模量增加120．4％，断裂伸长率明显下降。     

CF／TLCP／PESU热塑性复合材料研究

研究了热致液晶聚合物（ＴＬＣＰ）、玻璃纤维（ＣＦ）对ＣＦ／ＴＬＣＰ／ＰＥＳＵ（聚醚砜）复合材料加工性能和力学性能的影响,并对ＴＬＣＰ在体系中的形貌进行分析。结果表明,ＴＬＣＰ可以提高复合材料的拉弹性模量。     

Influence of viscosity ratio on processing and morphology of thermotropic liquid crystal polymer‐reinforced poly(ethylene 2,6‐naphthalate) blends

Thermotropic liquid crystal polymer (TLCP) microfibril‐reinforced poly(ethylene 2,6‐naphthalate) (PEN) composites with various intrinsic viscosities were prepared by a melt compounding method. Polymer composites consisting of bulk cheap polyester with a small amount of expensive TLCP are of interest from a commercial perspective. The TLCP acts as a nucleating agent in the TLCP/PEN composites, enhancing the crystallization of the PEN matrix through heterogeneous nucleation. The structural viscosity index of the TLCP/PEN composites was lower than that of PEN and TLCP, which was attributed to the formation of TLCP fibrillar structures with elongated fibrils in the PEN matrix. The TLCP/PEN composites with higher intrinsic viscosity than the polymer matrix contained these elongated fibrils, and had a TLCP component with a smaller average diameter, and a narrower diameter distribution than TLCP/PEN composites with lower intrinsic viscosity. The higher intrinsic viscosity of the polymer matrix, the higher shear rate and the lower viscosity ratio of TLCP to PEN can all favour TLCP fibrillation in the polymer composites. Copyright © 2006 Society of Chemical Industry     

UP/GF/TLCP原位混杂复合材料的性能研究

采用自行合成的双键液晶聚合物（TLCP），通过原位复合的方法制备了不饱和聚酯（UP）／玻璃纤维（GF）／TLCP原位混杂复合材料。研究了TLCP用量对UP／GF／TLCP复合材料的磨损性能、流变性能和材料表面电阻和体积电阻的影响。结果表明，TLCP用量对材料的流变性能、磨损性能和吸水性能有较大影响，当加入质量分数为5％的TLCP时，材料的流动性能最好，熔体体积流动速率达到0．097cm^3／s；当TLCP质量分数为7．5％时，材料的磨损量比未加TLCP的材料减少50％；随着TLCP用量的增加，材料的吸水性降低；TLCP用量对材料电性能影响不大。     

热致液晶聚酯—热塑性塑料合金的性能和应用前景

热致液晶聚酯(TLCP)—热塑性塑料(TP)合金是近年开发的新型高性能材料之一。本文介绍了该类合金的流变性能、加工特点、以及组成、温度、剪切速率、拉伸比、加工方式等对力学性能的影响。指出,该合金从性能和成本两方面看,是一种具有良好应用前景的新型高性能材料。     

Noticeable viscosity reduction of polycarbonate melts caused jointly by nano‐silica filling and TLCP fibrillation

Nano‐SiO₂ was introduced into in‐situ composites of polycarbonate (PC) and a thermotropic liquid crystalline polymer (TLCP) using a twin‐screw extruder. The rheology of these composites was characterized with capillary rheometry, and the morphology of the dispersed TLCP observed with scanning electron microscopy. The rheological data revealed that the viscosity decrease of PC melts by only the addition up to 20 wt% TLCP remained smaller than 30%, while it became ～48% upon further addition of only about 1 wt% nano‐SiO₂ and larger than 60% upon ～9 wt% nano‐SiO₂ filling, in contrast to a 50% viscosity increase of PC melts with increase in nanosilica loading up to ～9 wt%. These silica‐filled composites exhibited markedly low viscosity, especially at relatively high shear rates. The morphology of TLCP extracted from unfilled and silica‐filled composites indicated that the largest viscosity reduction was correlated well with the fibrillation of TLCP droplets enhanced by nano‐SiO₂. The TLCP/SiO₂/PC composites exhibited rheological hybrid effect with fillers at nanometer scale. POLYM. ENG. SCI., 47:757–764, 2007. © 2007 Society of Plastics Engineers     

Inhibited transesterification and enhanced fibrillation of TLCP by nano-SiO2 in polycarbonate matrix

Hybrid composites composed of a thermotropic liquid crystalline polymer (TLCP), nano-SiO₂ and polycarbonate (PC) were prepared by melt blending in a twin-screw extruder. Infrared spectroscopy analysis indicated that the transesterification between PC and TLCP molecules during melt blending was significantly reduced in TLCP/PC blends filled with nano-SiO₂, compared to the unfilled TLCP/PC one. Scanning electron microscopy (SEM) observation showed that better compatibility and finer TLCP dispersion were reached in the unfilled blend, which made the fibrillation of TLCP difficult in capillary flow even at high shear rate. In contrast to this, well-developed TLCP fibrils were formed by capillary flow in nano-SiO₂ filled TLCP/PC blends. By increasing the nano-SiO₂ concentration and shear rate, the fibrillation of TLCP was significantly enhanced. Thermodynamically the interfacial tension between these components and dynamically the viscosity ratio of TLCP to PC were used to investigate the mechanism of nano-SiO₂ in inhibiting the transesterification and enhancing the fibrillation of TLCP droplets in these hybrid composites.