聚对苯二甲酸乙二醇酯拓扑结构扩链的流变和发泡性能  

Topological structure chain extension modification of polyethylene terephthalate(PET)and its rheological behavior and foaming properties

作　　者：南婧文 周锦 黄文健 王秀华[1] 张须臻[1] NANJingwen;ZHOU Jin;HUANG Wenjian;WANG Xiuhua;ZHANG Xuzhen(School of Materials Science&Engineering,Zhejiang Sci-Tech University,Hangzhou 310018,China)

机构地区：[1]浙江理工大学材料科学与工程学院,杭州310018

出　　处：《现代纺织技术》2023年第5期86-95,共10页Advanced Textile Technology

基　　金：国家自然科学基金项目(52003241)。

摘　　要：为了通过设计具有拓扑长链的结构,增强聚对苯二甲酸乙二醇酯(PET)的熔体模量,改善其发泡性能,分别采用多官能团酸酐扩链剂均苯四甲酸酐(PMDA)和环氧扩链剂四环氧丙基二氨基二苯甲烷(TGDDM)对PET进行反应挤出改性。以核磁氢谱分析PET改性前后的化学结构,利用旋转流变仪和转矩流变仪对PET熔体的流变性能进行表征,同时通过化学发泡法研究改性PET的发泡性能。结果表明:两种扩链剂均成功对PET进行了拓扑扩链改性,且与PMDA相比,TGDDM改性PET具有更高的复数黏度、储能模量,更低的损耗因子值。两种扩链剂协同改性PET时,反应速率明显加快,复数黏度、储能模量较高。当PMDA质量分数为1.0%时,或TGDDM质量分数为0.7%时,改性PET内部开始出现凝胶结构。发泡实验结果表明PET经改性后发泡性能得以改善。Polyethylene terephthalate(PET)is widely used in fibers,bottle sheets and films because of its excellent physical properties.It is also one of limited materials that have realized industrial recyclization.Therefore,the development of foaming PET is of great significance to solve the pollution of express packaging waste.However,conventional PET has low molecular weight and straight chain,and its melt viscosity and elasticity are poor.It is difficult to form foam with complete cellular structure and good foaming properties.In this paper,based on the topological branching chain extension mechanism of PET,the topological chain extension modification of PET was carried out by reactive melt extrusion with multi-functional epoxy modifier and multi-functional anhydride modifier.PET was modified by tetraglycidyl diamino diphenyl methane(TGDDM),and the modification effect was compared with that of pyromellitic dianhydride(PMDA).The reaction ability of TGDDM to PET was analyzed.The rheological properties of PET were improved by extrusion modification with different amounts of chain extender PMDA TGDDM.The basic performance,thermal properties and rheological properties of the modified PET were compared with those modified with single chain extender.The optimized TGDDM-modified PET,PMDA-modified PET and TGDDM PMDA-modified PET with superior rheological properties were used as the raw materials,and were foamed via chemical foaming method.The cell morphology of the foamed samples was observed by scanning electron microscope to determine the internal relationship between foaming properties and rheological properties.The effects of foaming conditions on cell parameters were also studied by adjusting foaming temperatures,foaming times and foaming agent contents.The results show that both the two chain extenders have successfully modified PET.Compared that with PMDA,PET modified by TGDDM has higher complex viscosity,higher storage moduli and lower loss factor.When the two chain extenders cooperate to modify PET,the reaction rate is

关 键 词：聚对苯二甲酸乙二醇酯(PET) 酸酐扩链剂 环氧扩链剂 流变 发泡 

分 类 号：TQ328[化学工程—合成树脂塑料工业]