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。     

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。     

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.     

TLCP/PA66复合材料的熔融和结晶行为

双螺杆挤出制备热致液晶/尼龙 66(TLCP/PA66)复合材料,示差量热扫描(DSC)和X射线衍射(XRD)对复合材料的熔融和结晶等行为进行分析.结果表明:低含量的TLCP存在成核剂的作用使复合材料具有较高的结晶温度、结晶度以及完美的结晶形态;受到TLCP刚性分子链的影响,高含量TLCP使复合材料的熔点、结晶温度和结晶度等参数下降.XRD分析结果表明:TLCP促进复合材料晶体沿(010)和(110)面生长.     

热致液晶聚合物共混改性聚酰胺的研究进展

综述了近几年来热致性液晶聚合物(TLCP)与聚酰胺(PA)共混改性的研究进展,以及TLCP的加入对PA的熔融和结晶行为、粘度、形态结构以及力学性能方面的影响,并阐述了增容技术在共混改性中的重要性。     

热致液晶聚合物共混改性PC的研究进展

综述了近几年来热致性液晶聚合物(TLCP)与聚碳酸酯(PC)共混改性方面的研究进展，以及TLCP的加入对PC的熔融和结晶行为、粘度、形态结构以及力学性能的影响，并阐述了增容技术在共混改性中的重要性。     

热致液晶高分子膜的表面处理及化学镀铜

论文采用氢氧化钠(NaOH)溶液对Vecstar型热致液晶高分子(TLCP)膜表面进行刻蚀粗化,然后通过3-氨丙基三乙氧基硅烷(KH550)在膜表面引入氨基,利用氨基络合银离子使膜表面活化,再进行无钯化学镀铜,提升了TLCP膜与金属铜之间的黏附力。借助扫描电子显微镜(SEM)、接触角测量仪、X射线衍射仪(XRD)和剥离测试等对经表面处理及化学镀铜后的TLCP膜进行表征,探讨了NaOH溶液浓度、表面粗化温度和时间、活化溶液组成等对TLCP表面化学镀铜的影响。结果表明,经表面处理后TLCP膜表面产生均匀的孔洞,接触角下降至29.30°,亲水性大幅提高;所镀铜层呈光亮的粉色,带有金属光泽,致密平滑,纯度高,镀层厚度可达2.78μm,与TLCP膜间的附着力等级达到了5B。     

热致性液晶/酚醛树脂复合体系固化反应动力学

采用非等温DSC方法研究了不同升温速率下热致性液晶聚合物(TLCP)/酚醛树脂(PF)复合体系的固化行为,利用3种现象学模型(Ozawa及Kissinger简单模型、Kissinger-Akahira-Sunose(KAS)等转化模型)分析对比了TLCP/PF复合体系及纯PF体系的固化反应动力学,研究TLCP含量对TLCP/PF复合体系固化反应动力学的影响。结果表明,采用Ozawa和Kissinger2种方法计算得到TLCP/PF复合体系的固化反应活化能(Ea)结果一致;通过KAS模型得到TLCP/PF复合体系不同的固化度下的Ea;TLCP的加入加速了酚醛树脂固化反应,降低了酚醛树脂固化反应活化能,当TLCP的质量分数为10%时,Ea最小。     

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。     

热致液晶高分子与尼龙共混改性进展

综述了近几年来热致液晶聚合物（ＴＬＣＰ）与尼龙（ＰＡ）共混改性的新进展，简要介绍了ＴＬＣＰ的加入对ＰＡ的熔融和结晶行为、粘度、形态结构以及力学性能等的影响，并阐述了增容技术在共混改性中的重要性以及影响ＴＬＣＰ成纤的主要因素。     

热致性液晶高分子增强复合材料研究进展

从材料组成、共混加工、形态结构及材料性能诸方面对热致液晶高分子聚合物(TLCP)增强复合材料的最新研究进展进行了综述,并指出该材料良好的应用开发前景。     

Study on the miscibility and rheological properties of thermotropic liquid crystalline polymers in thermoplastic matrices

The interfacial properties of polymer blends of the engineering thermoplastics (TPs) polycarbonate (PC) and polyethersulfone (PES) with thermotropic liquid crystalline polymers (TLCPs) were studied using FTIR and DSC. The TLCP/TP blend systems were mainly immiscible. The viscosity properties of the TLCP/TP blends were analysed. The mechanism of the viscosity variation of the blends is discussed. Based on the assumptions given in this paper, a reasoned theoretical formula of the blend viscosity is derived to express the viscosity reduction of the TLCP/TP blends.     

热塑性聚合物／热致液晶聚合物原位复合材料的制备

介绍了热塑性聚合物 /热致液晶聚合物原位复合材料 (TP/TLCP)的加工。系统阐述了热塑性聚合物 /热致液晶聚合物原位复合材料制备过程中流场、剪切速率、拉伸比、加工温度和冷却速率对材料微纤形成和力学性能的影响。同时 ,将现有的加工方法归结为传统加工方法、新加工方法和其他加工方法三类 ,并详细分析了各种加工方法的优缺点。最后指出 ,今后对热塑性聚合物 /热致液晶聚合物原位复合材料的研究应致力于改善界面相容性、优化加工条件和开发新的加工方法     

Modification of the processing window of a thermotropic liquid crystalline polymer by blending with another thermotropic liquid crystalline polymer

This paper is concerned with properties and processing performance of two thermotropic liquid crystalline polymers (TLCPs) produced by DuPont (HX6000 and HX8000) with widely varying melting points and blends of these two TLCPs. This work was carried out in an effort to develop a TLCP suitable for generating poly(ethylene terephthalate) (PET) composites in which the melting point of the TLCP was higher than the processing temperature of PET. Strands of the neat TLCPs and a 50/50 wt % TLCP–TLCP blend were spun and tested for their tensile properties. It was determined that the moduli of the HX8000, HX6000, and HX6000–HX8000 blend strands were 47.1, 70, and 38.5 GPa, respectfully. Monofilaments of PET–HX6000–HX8000 (50/25/25 wt %) were spun with the use of a novel dual extruder process. The strands had moduli as high as 28 GPa, exceeding predictions made using the rule of mixtures and tensile strengths around 275 MPa. The strands were then uniaxially compression molded at 270°C. It was found that after compression molding, the modulus dropped from 28 GPa to roughly 12 GPa due to the loss of molecular orientation in the TLCP phase. However, this represents an improvement over the use of HX8000. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 2209–2218, 1999     

Synthesis and properties of liquid crystalline polymers with low Tm and broad mesophase temperature ranges

Novel thermotropic liquid crystalline polymers (TLCP) with improved processability and lower cost than Vectra^® were synthesized by esterification and melt polycondensation. Aromatic compounds, 6-hydroxyl-2-naphthoic acid, 2,6-naphthlenedicarboxylic acid, 4-hydroxybenzoic acid or terephthalic acid, were used as polycyclic stiff rod-like mesogenic groups. Aliphatic diol, ethylene glycol or 1,4-butanediol was used as flexible spacers to form semi-flexible main chain TLCP. The LCP products were characterized by FT-IR and ¹H NMR to identify their chemical structures. The analytical results showed the polymers had inherent viscosities of 0.35-0.54 dL/g. The crank shaft structure of the naphthalene decreased the melting temperature (T_m) of LCP (181-272 °C) to facilitate extrusion or injection molding, and maintained relatively high heat deflection temperature for high performance engineering plastics applications. The 5% weight loss decomposition temperatures were above 400 °C. LCPs have good solvent resistance and low hygroscopicity. The SEM morphology showed strong orientation on the surface in the flow direction and many micro-fibers structure in a sectional drawing. The optical textures of polymers observed by POM revealed a strong birefringence in the melts and indicated that they form nematic mesophase. All polymers have broad mesophase temperature (ΔT_meso) ranges.     

光致变色液晶聚合物的光致再取向性能研究进展

光致变色分子经掺杂或键合作用嵌在液晶聚合物中可形成光致变色液晶聚合物，在线性偏振光或非偏振光的照射下，此物质中光致变色分子的构型变化会引起整个液晶分子的二维或三维光致再取向的形成，本文综述了光致变色液晶聚合物的光致再取向的近期研究进展。     

Morphology evolution of a thermotropic liquid‐crystalline polymer in a polyamide 6,6 matrix regulated by graphene

A two‐step process, thermotropic liquid‐crystalline polymer (TLCP) premixing with reduced graphene oxide (RGO) followed by blending with polyamide 6,6 (PA66), was used to prepare ternary TLCP/RGO/PA66 blends. The rheological behaviors, morphology, and mechanical properties of the blends were investigated. The results show that RGO migrated from the TLCP phase to the interface between the TLCP and PA66 phase during melt blending; this was due to a similar affinity of the RGO nanosheets to both component polymers. The dimensions of the dispersive TLCP domains were markedly reduced with the mounting RGO content; this revealed a good compatibilization effect of RGO on the immiscible polymers. The hierarchical structures of the TLCP fibrils were found in both the unfilled TLCP/PA66 blends and TLCP/RGO/PA66 blends. This supposedly resulted from the extensional and torsional action of unstable capillary flow. With the addition of RGO, the viscosities of the blends decreased further, and the fibrillation of TLCP and the mechanical performance of TLCP composites were both enhanced. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43735.     

Carboxylated multiwall carbon nanotube-reinforced thermotropic liquid crystalline polymer nanocomposites

Thermotropic liquid crystalline polymer (TLCP) nanocomposites reinforced with carboxylated multiwall carbon nanotube (c-MWCNT) were prepared through melt compounding in a twin screw extruder. The thermal stability of TLCP/c-MWCNT nanocomposites increased with even a small amount of c-MWCNT added. The rheological properties of the TLCP/c-MWCNT nanocomposites were depended on the c-MWCNT contents. The contents of c-MWCNT have a slight effect on the complex viscosity of TLCP/c-MWCNT nanocomposites due to the high-shear thinning of TLCP. The storage modulus of TLCP/c-MWCNT nanocomposites was increased with increasing c-MWCNT content. This result can be deduced that the nanotube–nanotube interactions were more dominant, and some interconnected or network-like structures were formed in the TLCP/c-MWCNT nanocomposites. Incorporation of very small amount of c-MWCNT improved the mechanical properties of TLCP/c-MWCNT nanocomposites, and this was attributed to the reinforcement effect of c-MWCNT with high aspect ratio and their uniform dispersion through acid treatment in the TLCP matrix. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008