中文摘要：

在废弃PET瓶瓶片中添加不同质量分数的1，6-己二异氰酸酯（HDI）作为扩链剂，利用反应挤出技术在同向双螺杆挤出机中反应，分析测试反应产物的羧基质量摩尔浓度、羟基质量摩尔浓度、热学性能、特性黏度及力学性能。实验结果表明：HDI是一种有效的扩链剂，反应后PET特性黏度由0．66dL／g提高至0．92dL／g，摩尔质量亦显著提高，羧基质量摩尔浓度及羟基质量摩尔浓度下降近一半，同时断裂伸长率得到极大提高。

英文摘要：

With different contents of hexamethylenediisocyanate （HDI） as chain extender, reactive extrusion process for recycled PET flakes was conducted by means of a co-rotating twin screw extruder. The carboxyl content, hydroxyl content, thermal property, intrinsic viscosity and mechanical properties of the reaction product were tested and analyzed. The results showed HDI was an effective chain extender, after the reaction the intrinsic viscosity of the PET increased from 0.66 dL/g to 0.92 dL/g, the molecular weight was also increased abviously, carboxyl content and hydroxyl content decreased nearly by 50%, and the elongation at break was greatly improved.