注塑工艺参数对长玻纤增强PA66复合材料力学性能的影响

研究了注塑工艺参数对长玻纤增强PA66(LGF-PA66)复合材料力学性能和玻纤残余长度的影响。运用非连续纤维增强复合材料的拉伸强度和冲击强度模型来解释实验结果,并建立了工艺参数与LGF-PA66力学性能的关系曲线。结果表明:注塑工艺参数决定了玻纤的残余长度和取向,进而影响了LGF-PA66复合材料的力学性能。     

短玻纤增强PBT电击穿和力学性能的研究

以提高玻纤增强PBT材料在湿热环境下的电和力学性能为目标，研究了短玻纤品种和用量，加工助剂和加工条件的影响；探讨了干，湿态材料性能产生差异的原因。结果表明，使用直径较大（13μm)的短玻纤，PTFE的减摩和润滑作用，选用PEW作流动改性剂，控制较低的螺杆转速是有效措施，玻纤－PBT界面状况是影响干，湿态材料性能的支配因素。     

Interacting Blends of Flame-Retardant Acrylated Poly(Ester-Amide) Resins Based on Brominated Epoxy Resin with Methyl Methacrylate and Styrene

Bisphthalamic acids were prepared by reaction between phthalic anhydride and diamines. Flame-retardant poly(ester-amide)s (FR-PEAs) were prepared by reaction between bisphthalamic acids and brominated epoxy resin. Acrylation of FR-PEAs gives flame retardant acrylated poly(ester-amide)s (FR-APEAs). FR-PEAs and FR-APEAs were characterized by IR spectra, elemental analysis and number average molecular weight. Blending of FR-APEAs with methyl methacrylate and styrene was carried out. Curing study of these blends was monitored by Differential Scanning Calorimeter (DSC). Based on DSC data, glass and carbon reinforced composites have been laminated and characterized. The unreinforced cured samples were subjected to thermogravimetric analysis.     

SCRIMP用环氧树脂体系及其复合材料的性能研究

采用粘度、凝胶时间及力学性能测试以及示差扫描量热分析和扫描电镜研究了上纬环氧树脂2511-A体系的工艺性能,固化反应行为及其采用西曼树脂浸渍膜塑成型工艺(Seeman Composites Infusion Molding Process,SCRIMP)制成的环氧玻璃纤维复合材料的性能。结果表明:2511-A体系在25～35℃下粘度保持在600 mPa.s以下的时间长达120 min,满足SRCIMP成型工艺要求,其玻璃化转变温度为112℃。复合材料的孔隙率仅为0.19%,且具有良好的力学性能。     

A review on the mechanical and electrical properties of graphite and modified graphite reinforced polymer composites

Carbon materials particularly in the form of sparkling diamonds have held mankind spellbound for centuries, and in its other forms, like coal and coke continue to serve mankind as a fuel material, like carbon black, carbon fibers, carbon nanofibers and carbon nanotubes meet requirements of reinforcing filler in several applications. All these various forms of carbon are possible because of the element's unique hybridization ability. Graphene (a single two-dimensional layer of carbon atoms bonded together in the hexagonal graphite lattice), the basic building block of graphite, is at the epicenter of present-day materials research because of its high values of Young's modulus, fracture strength, thermal conductivity, specific surface area and fascinating transport phenomena leading to its use in multifarious applications like energy storage materials, liquid crystal devices, mechanical resonators and polymer composites. In this review, we focus on graphite and describe its various modifications for use as modified fillers in polymer matrices for creating polymer-carbon nanocomposites.     

Realizing the enhancement of interfacial interaction in semicrystalline polymer/filler composites via interfacial crystallization

Polymer/filler composites have been widely used in various areas. One of the keys to achieve the high performance of these composites is good interfacial interaction between polymer matrix and filler. As a relatively new approach, the possibility to enhance polymer/filler interfacial interaction via crystallization of polymer on the surface of fillers, i.e., interfacial crystallization, is summarized and discussed in this paper. Interfacial crystallization has attracted tremendous interest in the past several decades, and some unique hybrid crystalline structures have been observed, including hybrid shish-kebab and hybrid shish-calabash structures in which the filler served as the shish and crystalline polymer as the kebab/calabash. Thus, the manipulation of the interfacial crystallization architecture offers a potential highly effective route to achieve strong polymer/filler interaction. This review is based on the latest development of interfacial crystallization in polymer/filler composites and will be organized as follows. The structural/morphological features of various interfacial crystallization fashions are described first. Subsequently, various influences on the final structure/morphology of hybrid crystallization and the nucleation and/or growth mechanisms of crystallization behaviors at polymer/filler interface are reviewed. Then recent studies on interfacial crystallization induced interfacial enhancement ascertained by different research methodologies are addressed, including a comparative analysis to highlight the positive role of interfacial crystallization on the resultant mechanical reinforcement. Finally, a conclusion, including future perspectives, is presented.     

Modifications of carbon for polymer composites and nanocomposites

The various forms of carbon used in composite preparation include mainly carbon-black, carbon nanotubes and nanofibers, graphite and fullerenes. This review presents a detailed literature survey on the various modifications of the carbon nanostructures for nanocomposite preparation focusing upon the works published in the last decade. The modifications of each form of carbon are considered, with a compilation of structure-property relationships of carbon-based polymer nanocomposites. Modifications in both bulk and surface modifications have been reviewed, with comparison of their mechanical, thermal, electrical and barrier properties. A synopsis of the applications of these advanced materials is presented, pointing out gaps to motivate potential research in this field.