光盘级聚碳酸酯(PC)的回收利用技术

Recycling of Polycarbonate Used in Compact Disc

实验采用PE-g-MAH、MBS增韧PC,结果表明,PE-g-MAH/PC共混物冲击强度为纯PC的5倍,但仍为脆性断裂。MBS质量含量达10%时,PC合金开始表现为韧性断裂;MBS质量含量达15%时,MBS/PC共混物冲击韧性可为PC的30倍,达到399 J/m。对共混物损伤机制的研究表明,MBS增韧PC共混物的增韧机理为橡胶粒子的空洞化引发基体的剪切屈服。增韧体系符合Wu提出的临界粒间距模型。采用酯交换-缩聚法对PC进行扩链,研究表明,在300℃、1.5mmHg真空度下充分反应后,PC的分子量由29324提高到53035,且分子量分布略变窄。经超临界处理,PC的水解产物为双酚A。

The modification and chain-extension of polycarbonate were used to recycle the rejected plastics. PE-g-MAH and MBS were used to toughen PC. It was found that the impact strength of PC/PE-g-MAH blends was 5 times higher than that of PC, yet the material showed obviously brittle fracture. PC/MBS blends showed tough fracture when the content of MBS was 10%. When the content of MBS reached to 15%, the impact strength of PC/MBS blends was 399J/m,30 times higher than that of PC. Studies of the fracture showed that the mechanism of MBS toughening PC was that the cavitation of rubber particles induced the shear yielding of matrix. Because PC＇ s chain end was capped with phenol and had no carboxyl or hydroxyl group,it could not react with normal chain extender. The ester exchange reaction was used to enhance the molecular weight of PC. The study indicated that the molecular weight of PC was increased greatly under correct reaction condition and sufficient reaction time. The molecular weight range was narrower than the rejected plastics. The products of ester exchange reaction, diphenyl carbonete must be extracted with high vacuum to promote the chain - extension reaction of PC.