【作者】 张素文；

【导师】 王益龙；

【作者基本信息】 大连理工大学 ， 材料学， 2007， 硕士

【摘要】 对回收聚酯瓶片原料进行物性测试表明，实验所用回收聚酯瓶片原料的材质是纯聚对苯二甲酸乙二醇酯(PET，简称聚酯)，除此之外不含有其它聚合物，其特性黏度([η])的平均值为0.65dL／g。使用多种型号的挤出机研究了聚酯瓶片的反应挤出扩链情况和产品的[η]变化。实验结果表明，使用普通单螺杆或双螺杆挤出机时，产品的[η]均低于原料瓶片的[η]平均值；使用接枝型反应挤出机时，产物的[η]可达0.83dL／g，但是扩链剂用量较大；使用缩聚型反应挤出机时，挤出生产稳定，产品条韧性好，产物的[η]有较大程度的提高，均在0.70～1.0dL／g之间，并且使用缩聚型反应挤出机时可节约相当一部分扩链剂。大量实验证明，自行设计的缩聚型反应挤出机是提高聚酯[η]的理想反应设备。分别选用双噁唑啉(BOZ)、均苯四酐(PMDA)和两者混合物为扩链剂，用缩聚型反应挤出机研究了扩链剂的种类、扩链剂用量和加工工艺条件对回收PET产品的[η]影响。实验结果表明：在扩链剂用量均为0.2wt％时，BOZ可使产品的[η]提高0.09dL／g；BOZ和PMDA联用有一定的扩链效果，但不够理想；而使用PMDA最多可使产品的[η]提高0.35dL／g，达到1.0dL／g，扩链效果显著。使用PMDA为扩链剂时，反应挤出机的最佳工艺条件为：反应段温度260℃、螺杆转速45 r／min、真空度0.1MPa。研究了聚酯瓶片与一定量PMDA在密炼机中的反应情况，可知物料的停留时间在4～5min为宜。对扩链后产品进行测试表明，扩链后的PET产品与纯PET工业料完全相同，其热性能、晶型都没有改变，产品达到了中空吹塑加工聚酯瓶的要求。根据本实验结果设计制造了工业用反应挤出机组，使用该机组加工PET瓶片时，工业放大试验结果理想。发现原料的含水量、螺筒反应温度、真空度是影响产品特性黏度的重要因素。另外，以工业聚酯切片为原料，研究了其反应挤出扩链情况。实验结果表明：BOZ的扩链效果不明显；PMDA能较大程度的提高PET的[η]，但产品CV值较高；BOZ和PMDA联用可得到高[η]、低CV值的产品，扩链效果最佳。当挤出机工艺条件为：反应段温度260℃、螺杆转速45r／min、真空度0.1MPa、BOZ和PMDA用量均为0.2wt％时，可得到[η]为0.90dL／g，CV值为25 eq／10~6g的PET产品。更多还原

【Abstract】 Test the raw material by some methods and the results show that there is no any otherpolymer in the flakes but PET. The average intrinsic viscosity([η]) of the flakes is 0.65dL/g.The change of [η] and the extruded situation of PET were studied with variousextruders, including single screw extruder, twin-screw extruder, grafting reactive extruder andpolycondensation reactive extruder. Experiment results showed that PET product of higher[η]and good toughness were obtained from recycled PET flake of drink bottle withpolycondensation reactive extruder designed by ourselves. It is the best machine reactorsuitable to increase [η]of PET of all.The influence of chain extender kind, content and reactive processing conditions on [η]of extruate was studied carefully using the chain extenders of 2,2’-Bis(2-oxazoline) (BOZ),Pyromellitic dianhydride (PMDA) and the mixture of the both with polycondensation reactiveextruder during reactive extrusion processing. Experiments showed that when the amount ofextender was 0.2wt%, [η] of recycled PET was increased 0.09dL/g based on BOZ;Combining BOZ with PMDA as chain extenders [η] of PET had a certain extentimprovement; Meanwhile PET was increased to 0.85dL/g when the amount of PMDA wasonly 0.25wt%. The optimal reactive conditions were as follows: reactive zone temperature of260℃, screw rotation speed of 45rpm, vacuum degree of 0.1MPaDSC and WAXD analysis results showed that the reactive extruded recycled PET and thepure industrial PET had the same thermal properties and crystal lattice, which proved that thereactive extruded recycled PET was suited to process PET bottle.The industrial reactive extruder was designed according to the experiments and was putin practice to process the recycled PET flakes. The results were better. In addition, somefactors which influenced the [η] of chain-extended PET products were studied.Furthermore, the change of [η] and CV of extruates was studied carefully based on thePET chips with the polycondensation reactive extruder during reactive extrusion processing.Experiments showed that [η] of PET products could be increased on some extent whenPMDA and BOZ were used separately. A higher [η] (0.90dL/g) and lower CV(25 eq/10~6g) ofPET could be obtained at the reactive conditions as follows: reactive zone temperature of 260℃, screw rotation speed of 45rpm, vacuum degree of 0.1MPa, both 0.2wt% PMDA and 0.2%BOZ as the chain extender.更多还原