PC/EAA共混体系在加工过程中的反应

STUDY ON THE REACTION OF PC AND EAA DURING PROCESSING

采用差示扫描量热法(DSC)和核磁共振氢谱法(1H-NMR)研究了不同聚碳酸酯(PC)/乙烯-丙烯酸共聚物(EAA)共混体系在加工过程中的大分子反应,考察了有机金属催化剂二丁基锡DBTO)含量和反应时间对体系的影响.采用哈克(Haake)转矩流变仪的混合器作反应釜,索氏抽提器分离产物.结果表明,PC和EAA在加工中反应剧烈,在共混体系的界面原位形成接枝或交联的PC-EAA共聚物,随催化剂用量增大、反应时间延长易生成共交联的PC-EAA共聚物.但混合时间过长,体系的断链反应会加剧,生成产物不稳定.

The transesterification in polycarbonate/poly（ethylene- co-acrylic acid） （PC/EAA） melting blend system with the presence of dibutyltin oxide （DBTO） catalyst was investigated during compounding by means of a Haake torque rheometer. The characteristics of the products were evaluated by Soxhlet extraction and DSC, 1^ H-NMR analyses. The results showed that the transesterification reaction did take place in the PC/EAA blend system,grafted or co-crosslinked copolymers PC：EAA were in situ generated at the interface of the blends during processing; the extent of exchange reaction, the structure and stability of reaction products depended upon the mixing time and the content of the catalyst.With more catalyst and reaction time, more co-crosslinked copolymers were obtained.