【摘要】 在软硬段质量恒为5∶5,PEG分子量1000的PBT/PEG体系中添加一定摩尔含量的乳酸,合成了一系列PBT/PEG/LA嵌段共聚醚酯,其中乳酸占PBT硬段摩尔分数的0~30%。采用FT-IR,1H-NMR,DSC等方法表征了材料的结构,并测试了力学性能及降解性能。主链硬段和热学性质分析表明,随着乳酸占原PBT/PEG共聚物中PBT摩尔分数的百分比由0增加至30%时,PBT摩尔分数从83.70%下降至58.58%,硬段熔点(Tm,h)也从196.3℃下降至170.1℃。力学性能测试表明,较高的LA摩尔含量有利于纤维降解,但使其断裂强度有所下降。PBT/PEG/LA纤维的可降解性能主要取决于其主链结构、聚集态以及LA的摩尔含量,降解后纤维的断裂强度保留率Y(%)与降解时间t(week)的关系满足回归方程:Y=A+B1×t+B2×t2+B3×t3+B4×t4,相关系数R2>0.997。更多还原

【Abstract】 A series of PBT/PEG/LA block copoly(ether-ester) with the constant mass ratio(r=1) of soft to hard segment of PBT/PEG(Mn=1000) and LA molar fraction to PET hard segment varying from 0～30% were synthesized and characterized by means of intrinsic viscosity,FT-IR,1H-NMR,DSC,mechanical properties and degradation behavior.The analysis on the hard segments in the copolymer chain and the thermodynamic properties showed that the molar faction of PBT decreased from 83.70% to 58.58% and the melting points(Tm,h)of hard segments decreased from 193.6 ℃ to 170.1 ℃,with the increase of LA molar ratio from 0 to 30% to the molar faction of PBT in the initial PBT/PEG copolymer.The mechanical properties testing showed that the higher molar fraction of LA impacts degradation of fibers,while the lower one improves the tensile strength.The biodegradable properties of PBT/PEG/LA fibers are related to its chain structure,collective structure and the molar faction of LA.The regression equation based on the correlations between the remaining percent of tensile strength Y(%)of degradable fibers and time of degradation t(week) is Y=A+B1×t+B2×t2+B3×t3+B4×t4,and the coefficient of determination R2>0.997.更多还原