摘要
聚乳酸(PLA)是一种高模量、高强度的生物可降解热塑性聚酯.传统增塑剂通常是非生物可降解的,研究中采用低分子聚丁二酸己二醇酯(PHS)与左旋聚乳酸(PLLA)共混得到全降解体系.利用差示扫描量热仪、偏光显微镜及万能试验机对共混体系的相容性、结晶性能和力学性能进行了研究.结果表明:PLLA/PHS比值为100/0、95/5、90/10、85/15、80/20的结晶度分别为7.5%、8.7%、11.5%、14.1%、14.2%.随着PHS含量的增加,共混物的结晶度有所提高,表明PHS成功促进了PLLA结晶.此外,与纯PLLA相比,PLLA/PHS(80/20)的结晶速率增加10倍,半结晶时间缩短一半.共混体系的断裂伸长率从纯PLLA的不足10%提高至60%左右(PHS含量为20%),同时强度和模量略有降低.PHS含量增加,共混体系的弹性模量不断减小,由纯PLLA的2.25 GPa减小至PHS含量为20%时的1.86 GPa.
Abstract
Polylactic acid(PLA)is a high-modulus,high-strength biodegradable thermoplastic polyester used in the packaging,textile and medical industries.Conventional plasticizers are usually non-biodegradable,the study used low molecular polyhexanediol succinate(PHS)blended with poly(L-lactic acid)(PLLA)to obtain a fully degradable system.The compatibility,crystallization and mechanical properties of the blended system were investigated by differential scanning calorimetry,polarizing microscope and universal testing machine.The results show that the crystallinity of PLLA/PHS ratios of 100/0,95/5,90/10,85/15,and 80/20 were 7.5%,8.7%,11.5%,14.1%,and 14.2%,respectively.The crystallinity of the blends increased with increasing PHS content,indicating that PHS successfully promoted PLLA crystallization.In addition,the crystallization rate of 80/20 was increased 10-fold and the semi-crystallization time was halved compared to pure PLLA.The elongation at break of the blends increased from less than 10%for pure PLLA to about 60%(PHS content 20%),with a slight decrease in strength and modulus.The elastic modulus of the blends decreased continuously with the increase of the PHS content,from 2.25 GPa for pure PLLA to 1.86 GPa at 20%PHS content.
基金项目
国家自然科学基金青年科学基金项目(52203030)
中国石油大学(北京)科研基金(2462022BJRC008)
维普
万方数据