超临界二氧化碳诱导结晶对聚乳酸发泡行为的影响  

Influence of Supercritical Carbon Dioxide Induced Crystallization on Foaming Behavior of Poly(lactic acid)

作　　者：杨永潮 张冲 陈绪煌 余鹏 Yongchao Yang;Chong Zhang;Xuhuang Chen;Peng Yu(School of Materials and Chemical Engineering,Hubei Provincial Key Laboratory of Green Materials for Light Industry,Collborative Innovation Center of Green Light-Weight Materials and Processing,Hubei University of Technology,Wuhan 430068,China;Dongfeng Yanfeng Automotive Trim Systems Co.,Ltd,Wuhan 430014,China)

机构地区：[1]湖北工业大学材料与化学工程学院,湖北工业大学绿色轻工材料湖北省重点实验室,湖北工业大学绿色轻质材料与加工协同创新中心,湖北武汉430068 [2]东风延锋汽车饰件系统有限公司,湖北武汉430014

出　　处：《高分子材料科学与工程》2019年第8期69-74,共6页Polymer Materials Science & Engineering

基　　金：国家自然科学基金资助项目(51703054);湖北省自然科学基金资助项目(2017CFB284);湖北省教育厅青年人才项目(Q20171409);绿色轻工材料湖北省重点实验室开放基金(201511-3);湖北工业大学博士科研启动项目(BSQD2015005)

摘　　要：采用超临界二氧化碳(SC-CO2)高压釜发泡方法,研究了SC-CO2诱导等温结晶对聚乳酸(PLA)泡孔结构的影响。利用差示扫描量热仪和偏光显微镜分别表征SC-CO2诱导等温结晶的结晶度和结晶形态。研究结果表明,泡孔结构不仅取决于结晶度,还与晶体形貌密切相关。根据结晶度和形态与泡孔结构之间的关系,将发泡温度划分为3个区间,在80℃时,SC-CO2诱导等温结晶形成中心非环带球晶,外部环带球晶的晶体结构,导致泡孔结构中出现大量未发泡区域;在90~110℃时,形成了环带球晶结构,产生较均匀的泡孔结构;在120~130℃时,形成了不规则的球晶结构,结晶度大幅度降低,泡孔结构出现合并和塌陷。通过调控发泡温度和形成特定的晶体结构,可以制备出具有不同泡孔结构的发泡材料。Through supercritical carbon dioxide(SC-CO2) autoclave foaming method, the effects of SC-CO2 induced isothermal crystallization on the cellular structure of polylactic acid(PLA) foams were investigated. The crystallinity and morphology of SC-CO2 induced isothermal crystallization were characterized by differential scanning calorimetry(DSC) and polarizing optical microscope(POM), respectively. The results show that not only the crystallinity but also the crystalline morphology is closely related to cellular structure. Based on the relationship between crystallinity, morphology and cellular structure, the foaming temperature can be divided into three regions. At 80 ℃, ringless spherulites in the core and ring-banded spherulite in the surrounding are formed by SC-CO2 induced isothermal crystallization, resulting in appearance of unformed areas. At the range of 90~110 ℃, only ring-banded spherulites are formed, which produce uniform cellular structures. At the range of 120~130 ℃, it produces disorder spherulite structures and the crystallinity decreases dramatically, resulting in the coalescence and collapse of cells. The desired foam structures could be produced through the controlling foaming temperature and formation of specific crystal structures.

关 键 词：超临界二氧化碳 聚乳酸 结晶 泡孔结构 

分 类 号：TQ328.06[化学工程—合成树脂塑料工业]