Papers by Author: Guo Hua Luo

Abstract: We proposed a method to enhance the heat removal in the synthesis process of PPTA (p-phenylene terephthalamide) by adding liquid nitrogen. Compared to the indirect heat removal method by ice-water bath, the heat removal method with liquid nitrogen can absorb reaction heat in much larger amount, and consequently allows the operation at an obvious lower temperature. The high inherent viscosity (ηinh) of the PPTA suggests that the quality of the product is very high, indicating the good temperature control by using liquid nitrogen. The results indicate that the introducing of liquid nitrogen effectively transfers the reaction heat to avoid overheating during the polymerization of PPTA, with simple operation process and low cost.

Abstract: Multi-walled carbon nanotube (MWNT) was filled into poly (ethylene terephthalate) (PET) matrix and MWNT/PET composite was prepared by injection molding process. The microstructure and electrical conductive property were investigated carefully. After injection molding, the electrical conductivity of injected sample decreased sharply because of the orientation of CNT due to strong shearing force. The electrical conductive network of CNT had been destroyed after orientation of CNT. Because of the difference of shearing rate between the surface and the body center during the injection molding process, a skin-core structure emerged. Near the surface, the injected sample has higher degree of orientation of CNT and higher electrical resistance.