全生物基脂肪/芳香族不饱和共聚酯的合成及其性能研究

以生物基3,4-二羟基肉桂酸(DHCA)和蓖麻油酸(RA)为单体,采用熔融缩聚法合成了二者的共聚物PDH及DHCA的均聚物PD。采用FTIR、DSC、1H NMR、GPC和荧光分析等方法对PDH和PD进行了表征。实验结果表明,PDH中DHCA与RA结构单元的比例与聚合反应时单体加入量(n(DHCA)∶n(RA))基本一致;反应体系中RA的加入有利于提高PDH的相对分子质量,且大于PD的相对分子质量,当n(DHCA)∶n(RA)=4∶3时聚合产物PDH的数均相对分子质量为2.78×104;随PDH中柔性链段RA含量的增加,PDH的玻璃化转变温度降低,断裂伸长率增大,降解速率变慢,PDH中DHCA含量的降低使得分子结构的共轭性整体有所下降。

Synthesis and Properties of Bio-Based Alkyl/Aromatic Unsaturated co-Polyester

Bio-based alkyl/aromatic unsaturated co-polyester(PDH) was synthesized from 3,4-dihydroxycinnamic acid(DHCA) and ricinoleic acid(RA),and homo-polyester of DHCA(PD)was synthesized from DHCA through thermal polycondensation.PDH and PD were characterized by means of FTIR,DSC,1H NMR,GPC and fluorescence spectrophotometer.The results showed that n(DHCA)∶n(RA) in PDH molecular was almost the same as that of the reactants;adding RA in the reaction system could increase the average relative molecular mass of PDH,which was bigger than that of PD,and the number average relative molecular mass of PDH was as high as 2.78×104 when n(DHCA)∶n(RA) was 4∶3 in the reaction system;with the increase of RA percentage in PDH,glass transition temperature of PDH decreased,its elongation at break increased,its degrading rate became slower,and decreasing DHCA percentage in PDH led to declining of the conjugation of PDH molecular structure.