盐泥对PVC热稳定作用的研究

本文采用电导法将盐泥(SM)与赤泥(RM)、石英、硼泥等对PVC脱HCl特性的影响进行了比较,考察了SM用量、环境气氛及温度对SM稳定效果的影响并对SM的稳定机理和SM/PVC体系的降解活化能进行了讨论。结果表明,SM对PVC具有优良的稳定作用,它可中和PVC受热放出的HCl,还能部分取代PVC分子链上的不稳定氯原子;其稳定作用随用量的增加而增加,当用量为60PHR时,其热稳定效果已超过5PHR二盐或5PHR三盐,并且用量越大,PVC体系的热稳定性受温度的影响越小,PVC的降解活化能越低;其用量在60PHR以上时可在一定程度上增加PVC的热氧稳定性。

Studies of the Effect of SM on Thermal Stability of PVC

The effect of salt mud (SM) red mud (RM),quarts and boron mud on dehydrochlorination of PVC was studied by conductance method ,the effect of thew adding amount ,condition and temperature on the Stabilization of SM was examined ,and the stabilization machanism and the activation energy of degradation of SM/PVC system were discussed. The results showed SM had good stabilization on PVC, could neutralize HCl released from heated PVC and partially substitute the unstable chlorine atom in PVC molecular chain ; the stabilization increased with the increase of the adding amount of SM, it was superior to that of 5 phr bibasic lead sulfate of 5 phr tribasic lead sulfate when the adding amount was 60 phr,and the more SM ,the weaker effect did temperature have on the stabilization ,and the weaker the activation energy of degradation ;the thermal-oxidative stability of PVC could be improved to a certain extent when the adding amount of SM was over 60 phr.