文献类型：期刊文献

中文题名：高熔体弹性PLA/咖啡渣复合材料的发泡行为研究

英文题名：Study on Foaming Behaviors of High Melt-elastic PLA/Coffee Ground Composites

作者：刘伟 何仕成 杨余杰 王跃 周洪福

第一作者：刘伟

机构：[1]贵州理工学院材料与冶金工程学院;[2]北京工商大学中国轻工业绿色塑料成型技术与质量评价重点实验室

第一机构：贵州理工学院材料与冶金工程学院

年份：2018

卷号：32

期号：5

起止页码：48-54

中文期刊名：中国塑料

外文期刊名：China Plastics

收录：CSTPCD;;Scopus;北大核心:【北大核心2017】；CSCD:【CSCD2017_2018】；

基金：国家自然科学基金(51703039);黔科合[2016]支撑项目(2806)

语种：中文

中文关键词：聚乳酸;咖啡渣;二苯基甲烷二异氰酸酯;发泡;扩链反应

外文关键词：poly（lactic acid）;coffee grounds;diphenylmethane diisocyanate;foaming behavior;chain extending reaction

摘要：通过熔融共混法制备二苯基甲烷二异氰酸酯(MDI)改性的聚乳酸(PLA)/咖啡渣复合材料,利用超临界CO_2对复合材料进行发泡,并对复合材料的流变性能、热性能、力学性能及发泡行为进行了研究。结果表明,MDI与PLA发生扩链反应,PLA/咖啡渣复合材料的熔体弹性、热性能和力学性能均显著提高;MDI能促进诱导冷结晶和熔融双峰形成,使复合材料的冷结晶度提高至24.68%;加入MDI后,PLA/咖啡渣复合材料的泡孔密度和发泡倍率明显提高;在诱导冷结晶的温度下发泡,PLA/咖啡渣复合材料的泡孔密度和发泡倍率分别达到9.26×10~6个/cm^3和9.33倍。
The preparation of PLA/coffee ground composites modified with diphenylmethane diisocyanate（MDI）was carried out by a melt-mixing method,and the resulting composites were formed by using supercritical CO2 as a foaming agent.The thermal,rheological and mechanical properties of composites were studied and their foaming behavior was investigated.The rheological results indicated that the melt elasticity of composites was improved in the presence of MDI due to a chain-extending reaction.The thermal and mechanical properties of composites were also influenced by MDI and coffee grounds.A bimodal behavior was observed in differential scanning calorimetric thermograms due to the melting and cold crystallization of PLA.The degree of cold crystallinity of PLA was improved up to 24.68 % due to the chain extension of MDI,which also resulted in an improvement in the impact resistance of the composites.Moreover,the composite foams achieved a cell density of 9.26×10^6 cell/cm^3 and a foaming expansion ratio of 9.33.This indicated that the incorporation of MDI favored an improvement in melt elasticity for PLA/coffee ground composite and thus could well control the cellular structure of PLA foams.