Study On R-PET/PC Engineering Plastics Alloy Prepared From Recycled PET Bottle Flakes

The r-PET(recycled PET flakes)/PC(polycarbonate) high-performance Engineering Plastics are prepared by the method of reactive extrusion.The effects of different kinds of extruders,different kinds and contents of catalysts on the melt flow rate(MFR),viscosity([η]) and mechanical properties of alloys are studied to explore the most appropriate PC content,the kind and content of catalysts,the kind of the extruder and the properties of the products.R-PET/PC alloy with different PC contents are produced with reactive extruder to study the effect of PC content on MFR,[η]and mechanical properties of r-PET/PC.The results show that,reactive extruder can improve the properties of the product better than the twin-screw extruder including MFR and[η].When the PC content is 15-20%,the[η]of the product is 0.73dL/g;tensile properties enhance 15.1%;elongations at break enhance 55.5%, charpy impacts strength(5.21 kJ/m²) enhance 51.9%,compared to the pure r-PET.When the content of PC is above 30%,we can't obtain strips in both reactive extruder and twin-screw extruder.The phenomone we call "worm" happenes,the strips sometimes gether together,sometimes elongate into slices.The sepration of two phases is oberserved in SEM in evidence.Ce(Ac) 3 is introduced to solve the compatibility between r-PET and PC as the catalyst of transesterification.The results show that transesterification occurs in the presence of little Ce(Ac)₃ and it making possible to extrude r-PET/PC under any proportion;the[η]of the product increases when Ce(Ac)₃ content increases,can achieve 0.82dL/g;The mechanical properties of r-PET/PC/Ce(Ac)₃ have been enhanced in magnitude compared to pure r-PET,for example, the un-notched charpy impact strength is 4.7 times than that of r-PET.But Ti(OC₄Hg)₄ can't be used as the catalyst of transesterification to improve the compatibility between r-PET and PC because it can't be well mixed.The effects of PMDA on the properties of r-PET/PC are studied with reactive extruder and twin-screw extruder.The results show that the mechanical properties of r-PET/PC are improved adding PMDA,but the[η]are not improved.Compare other two different kinds of chain extenders BOZ and phthalic anhydride,The results show that the[η]of r-PET/PC/ phthalic anhydride are remained the same as r-PET;The[η]of r-PET/PC/BOZ decrease, which means BOZ makes r-PET decomposed.