The Research Of Low Temperature Toughness Of Pocarbonate

Polycarbonate is currently one of the five major engineering plastic.Consumption is only second to nylon.PC has the excellent room temperature methanical properties,dimension stability,themal stability,flame retardancy and electric insulation,but the toughness of low temperature is poor,and PC is very sensitive to thickness and notch.Through adding rubber to PC,we can improve the low temper-ature toughness and sensitivity of the thickness and notch.This thesis is divided into two parts.the first part is the research of the mechanical properties,low temperature toughness, compatibility of PC/ABS alloy;the second part is the research of the mechanical properties,low temperature toughness,rheological properties of core-shell toughening agent toughening PC blends.We use processing and analysis equipments such as double screw extruder,injection,molding machine,universal testing machine,impact testing machine,DSC in the experiments. Different ratio and different adding amount of compatilizer of PC/ABS alloy was prepared in the first part.The mechanical properties,compatibility and low temperature toughness of PC/ABS alloy are studied. The research results show that the mechanical properties of PC/ABS alloy increase with the increase of PC content.when the PC content is less than40%, The mechanical properties of PC/ABS alloy increase quickly with the increase of PC content;When the PC content exceeds40%, the mechanical properties of PC/ABS alloy increase slowly.The PC/ABS alloy is particially compatible system.the compatilizer play little role in the mechanical properties of PC/ABS alloy.Adding ABS can improve the impact toughness of PC at-20℃.The notched strength of the alloy with the ratio of PC/ABS90/10,80/20,70/30are515.8J/m,459.4J/m,426.3J/m respectly,which is much higher than PC at-20℃.The above results illustrate that ABS can significantly improve the notched impact strength of PC at-20℃,but the effect is not obvious at-40℃.The second part is the modification of polycarbonate by using three kinds of core-shell toughening agents:butadiene-based toughening agent, siloxane-based toughening agent, acrylic ester toughening agent. The room temperature mechanical properties,Iow temperature toughness, rheology, weather resistance, flame retardant of the blends was investigated. The result show that core-shell toughening agents reduce the mechanical properties of PC at room temperature, increase the processing viscosity, but improve the low temperature toughness, weaken the thickness sensitivity, improve the flame retardant of PC with the addition of Siloxane-based toughening agent. At the same time, the influence of the maleic anhydride grafted polystyrene(SMA) compatilizer on PC blends mechanical properties was investigated.The third part is the effect of antistatic agents on the PC antistatic performance. Using antistatic agent of carbon black and surfactants,we study the antistatic property of PC.We also study the antistatic performance with antistatic coating.We test the surface antistatic resistance and impact strength of PC.According to the results,we find that the PCwith8%CB or antistatic coating is up to the antistatic performance.the impact strength of PC with adding8%change from828.8J/m to128.1J/m, while the impact strength of PC with antistatic coating change little.