Preparation And Properties Of Mulitfunctional Polystyrene/Graphite Composites

Due to its distinct electrical and thermal conductivity as well as excellent chemical stability, graphite material has been envisaged as one of promising fillers for the preparation of polymer composites with high performance and multifunctions. Polystyrene (PS) is one of the most generally-used commercial thermoplastic resins, which owns good performance and processing properties. As one kind of organic material, however, PS is an electrical and thermal insulator, and also flammable, these shortcomings limit the application of PS in higher level. Therefore, in order to address this issue some kinds of functional fillers have been added into PS by researchers to satisfy different requirement in manufacturing. And so far, these studies have achieved good results.In view of the excellent properties of graphite, which includes superfine graphite (SG), expansible graphite (eG) and expanded graphite (EG), the PS/graphite composites were prepared by melt mixing in this work. Furthermore, in order to realize the potentials of the graphite materials in polymer composites, it is inevitable to resolve the challenging problems of uniformly dispersing of graphite materials in PS matrix. So, the PS/graphite (SG, eG and EG) master batches have been prepared to achieve the homogeneous coating with PS on the surface of graphite materials. Tensile properties, electrical conductivity, limiting oxygen index (LOI) and cone calorimeter test of the resultant composites have been primarily studied. The results suggest that application of SG, eG and EG significantly improves the tensile properties and the flame resistance of composites, and also noticeably increases the electrical conductivity. For all things considered, especially the Flame resistance and cost performance, eG and EG are more suitable for preparing the PS/graphite multifunctional composite materials.The most important content of this work is to achieve the thermostability and flame resistance of composites. In previous work, we prepared PS/graphite composites with high performance and selected eG and EG for special researching. In the meantime, in order to further improve the flame resistance of PS/graphite composites, flame retardant bisphenol A bis(diphenyl phosphate)(BDP) was chosen to prepare PS/BDP/graphite composites with various eG, BDP and EG, BDP weight ratios. Mechanical property, electrical conductivities, thermostability and flame resistance of the resultant composites have been further studied. The results suggest that application of BDP not only betters the thermostability and the flame resistance but also noticeably increases the electrical conductivity.