反应挤出酯交换法制备r-PET/PC合金

r-PET/PC alloy prepared via transesterification in reactive extruder

使用反应型挤出机研究了在乙酸铈催化作用下同收聚对苯二甲酸乙酯饮料瓶片(r-PET)和聚碳酸酯(PC)的挤出反应情况、产物的特性黏数、熔体流动速率和力学性能变化结果表明,加入少量的乙酸铈可使部分大分子链发生酯交换反应,促进了高结晶性PET和非晶性PC间的相容性,使两者可以任意比例混合而正常地挤出。酯交换使产物的特性黏数提高、最高达0.82dL/g;加入质量分数为0.045%的乙酸铈,挤出反应产物r-PET/PC的力学性能比纯r-PET有明显提高,简支梁无缺口冲击强度比纯r-PET提高4.7倍。

The authors studied the reaction of recycled polyethylene terephthalate flakes （r-PET） with polycarbonate （PC） in the presence of Ce（Ac）3 catalyst in an reactive extruder and analyzed the variation in intrinsic viscosity, melt flow rate （MFR） and mechanical properties of the resultant extrudate. The results indicate that adding a small amount of Ce（Ac）3 can significantly promote transesterification occurred among a portion of the macro- molecular chains, improve the compatibility between the high-crystallinity r-PET and the amorphous PC and make both resins be able to blend at any proportion and extrude under conventional operation conditions. The transesterification leads to an increase, up to 0.82 dL/g as maximum, in intrinsic viscosity of the resultant extrudate; the mechanical properties of the r-PET/PC blend prepared under the condition of adding 0.045% Ce（Ac）3 by mass is significantly higher than those of pure r-PET. The non-notched Charpy impact strength of the r-PET/PC blend is raised by 4.7 times compared with the pure PET, the improvement verifies the realization of the goal for toughening r-PET with PC.