淀粉基纳米胶囊增韧聚乳酸  

Toughening of polylactic acid by starch based nanocapsule

作　　者：王琴 孟兵[3] 何沛玉 魏成 刘豊瑞 刘一丁 康彪 WANG Qin;MENG Bing;HE Peiyu;WEI Cheng;LIU Fengrui;LIU Yiding;KANG Biao(College of Chemistry and Chemical Engineering,Southwest Petroleum University,Chengdu 610500,China;Institute of Chemical Materials,China Academy of Engineering Physics,Mianyang 621900,China;Chengdu Aeronautic Polytechnic,Chengdu 610100,China)

机构地区：[1]西南石油大学化学化工学院,成都610500 [2]中国工程物理研究院化工材料研究所,四川绵阳621900 [3]成都航空职业技术学院,成都610100

出　　处：《工程塑料应用》2024年第7期155-161,共7页Engineering Plastics Application

基　　金：四川省科技创新人才计划项目(No.2023JDRC0006);国家自然科学基金项目(No.21902131)。

摘　　要：针对聚乳酸(PLA)材料本身存在的脆性和价格高等问题,以生物可降解的廉价淀粉为基础,构建纳米胶囊,然后将其作为纳米填料添加到PLA基体中,研究了PLA复合材料的力学性能。通过改变羟乙基淀粉(HES)/聚乙二醇(PEG-400),2,4′-和4,4′-二苯基甲烷二异氰酸酯混合物(MDI-50)的比例,制备了不同组成的纳米胶囊,并探讨了其对PLA的增韧机理。利用透射电子显微镜、傅里叶变换红外光谱仪和动态光散射详细表征了纳米胶囊的形貌、组成和尺寸;使用万能试验机对PLA复合薄膜进行拉伸性能测试;通过计算纳米胶囊间的平均粒径和差示扫描量热仪测试结果讨论纳米胶囊的增韧机理。结果表明,纳米胶囊的平均直径约为120 nm,且制备的PLA复合材料具有出色的断裂韧性,与纯PLA膜相比,断裂韧性最高提升了909%;在纳米胶囊间平均距离239~162 nm范围内存在一个临界粒间距离,使基体韧性出现一个突变增长,满足脆性向韧性转变的临界要求;纳米胶囊的增韧效果随黏弹性的增加而增加,与纳米胶囊的玻璃化转变温度呈负相关关系。To address the two problems of brittleness and high price of polylactic acid(PLA)material itself,the mechanical properties of PLA composites were investigated and analyzed by constructing nanocapsules based on biodegradable and cheap starch,which was then added as a nano-filler to the PLA matrix.By varying the ratio of hydroxyethyl starch(HES)/polyethylene glycol(PEG-400),2,4′-and 4,4′-diphenylmethane diisocyanate mixtures(MDI-50),nanocapsules with different compositions were prepared and the mechanism of the toughening effect of the nanocapsules for PLA was explored.The morphology,composition and size of the nanocapsules were characterized in detail using transmission electron microscopy,Fourier transform infrared spectroscopy and dynamic light scattering;the mechanical properties of the PLA composite films were tested using a universal testing machine;and the toughening mechanism of the nanocapsules was discussed by the calculated average particle size between the nanocapsules and the results of the differential scanning calorimetry test.The results show that the average diameter of the nanocapsules is about 120 nm and the prepared PLA composites have excellent toughness,which is increased by up to 909%compared with the pure PLA film;there exists a critical intergranular distance between the average distance between the nanocapsules,239 nm to 162 nm,which results in an abrupt increase in the toughness of the matrix and meets the critical requirements for the brittle-to-toughness transition;as the viscoelasticity increases,the toughening effect of nanocapsules also increases,which is negatively correlated with the glass transition temperature of nanocapsules.

关 键 词：聚乳酸 淀粉 纳米胶囊 增韧 细乳液聚合 

分 类 号：TQ050.43[化学工程]