聚丙烯流延膜的制备与拉伸过程中的结构演变  

Fabrication of isotactic polypropylene casting film and its structural evolution during stretching

作　　者：张博[1] 李壮壮 赵丹[1] 钱翠珠[1] 王宝[2,3] 潘鹏举 ZHANG Bo;LI Zhuangzhuang;ZHAO Dan;QIAN Cuizhu;WANG Bao;PAN Pengju(China Tobacco Zhejiang Industrial Company Limited,Hangzhou 310009,Zhejiang,China;State Key Laboratory of Chemical Engineering,College of Chemical and Biological Engineering,Zhejiang University,Hangzhou 310027,Zhejiang,China;Institute of Zhejiang University-Quzhou,Quzhou 324000,Zhejiang,China)

机构地区：[1]浙江中烟工业有限责任公司,浙江杭州310009 [2]浙江大学化学工程与生物工程学院,化学工程联合国家重点实验室,浙江杭州310027 [3]浙江大学衢州研究院,浙江衢州324000

出　　处：《化工学报》2023年第12期4997-5005,共9页CIESC Journal

基　　金：国家自然科学基金青年基金项目(22303080)。

摘　　要：高分子薄膜在加工过程中往往经历复杂的温度场以及拉伸场,拉伸通过诱导分子链取向而影响聚集态结构,进而影响薄膜各项性能。由于β晶聚丙烯(i PP)具有更好的力学性能,通过加入稀土类β成核剂(WBG)提高了i PP中β晶含量,并且利用流延的方法制备了i PP流延膜,研究了流延以及后拉伸条件对i PP结晶结构的影响。研究结果发现,随着牵伸比的增加以及流延温度的降低,i PP的结晶度增大,β晶含量减少,同时流延膜具有更高的拉伸强度。在后拉伸过程中,增加拉伸温度和应变能够促进β晶向α晶的转变,并且流延膜在拉伸后期出现空洞结构,基于此制备了i PP微孔膜。Polymer films often experience complex temperature fields and tensile fields during processing.Stretching affects the aggregated structure by inducing molecular chain orientation,thereby affecting various properties of the film.Compared to other crystal modifications,βcrystal isotactic polypropylene(i PP)has much better mechanical properties.In this work,we used WBG to improve theβcrystal content of i PP and investigated its structural evolution during casting and post-stretching.With the increase of draw ratio and the decrease of temperature,the crystallinity and tensile strength of i PP casting film increase,however,theβcrystal content decreases.During the post stretching process,increasing the stretch temperature and strain accelerates the transition of i PP fromβcrystal toαcrystal.Meanwhile,cavitation occurs at the late stage of post-stretching,which provides the foundation of i PP microporous membrane preparation.

关 键 词：聚丙烯 Β成核剂 膜 高分子加工 结晶 

分 类 号：TQ325.1[化学工程—合成树脂塑料工业]