回收PET瓶片/接枝PE反应共混物的形态及性能

Morphology and mechanical properties of reactive blend of recycled PET flakes and PE-g-MAH

利用有反应活性的各种接枝聚乙烯(PE)作为回收聚对苯二甲酸乙二酯(PET)瓶片的改性剂,使接枝PE上的活性酐基与PET的端羟基在不同的挤出设备中熔融反应,制备相分散均匀、力学性能较好的PET基工程塑料。结果表明,挤出设备的选择对混合效果影响较大,缩聚型反应挤出机和双螺杆挤出机比普通单螺杆挤出机具有更优良的混合效果:各种接枝PE的改性效果优劣次序是:马来酸酐接枝线型低密度聚乙烯,马来酸酐接枝低密度聚乙烯.马来酸酐接枝高密度聚乙烯;接枝PE添加质量分数为20%时,可大幅度提高反应共混物的冲击性能。

Several kinds of maleic anhydride grafted polyethylene （PE-g-MAH） resins with reactive activity were utilized as modifier for recycled polyethylene terephthalate （PET） flakes. PET-based engineering plastic featuring homogeneous phase distribution and superior mechanical properties could be prepared via the melt reaction of anhydride group of PE-g-MAH with hydroxyl of PET in different extruders. The experimental results demonstrate that type selection of the extrusion equipment greatly impact the mixing efficiency; poly condensation reactive extruder and twin screw extruder have the advantage over their conventional counter part in mixing efficacy. The sequence in modification capability of diverse PE-g-MAH can be listed in descending order as follows： maleic anhydride grafted linear low density polyethylene （LLDPE-g-MAH） 〉 maleic anhydride grafted low density polyethylene （LDPE-g-MAH） 〉 maleic anhydride grafted high density polyethylene （HDPE-g-MAH）. Adding appropriate amount （usually not higher than 20% in mass fraction） of the grafted PE can increase in great magnitude the impact property of the resultant copolymer.