生物基甘油酯类增塑剂的合成及性能

Synthesis and properties of bio-based glyceryl ester plasticizers

以甘油和不同结构脂肪酸(正辛酸、2-乙基己酸、正戊酸和2-甲基丁酸)为原料,采用直接酯化法制备了甘油酯类生物基增塑剂[甘油三辛酸酯、甘油三(2-乙基己酸)酯、甘油三戊酸酯和甘油三(2-甲基丁酸)酯]。利用FTIR和^(1)HNMR对其结构进行了表征。对比了4种增塑剂塑化的聚氯乙烯(PVC)试片与邻苯二甲酸二(2-乙基己)酯(DEHP)塑化的PVC试片的性能。结果表明,与DEHP塑化的PVC试片相比,甘油三戊酸酯/PVC试片的断裂伸长率提高151.0%;甘油三辛酸酯/PVC试片的初始降解温度(T_(5%))提高12.3℃;甘油三(2-甲基丁酸)酯/PVC试片的耐抽出性更好,均具有替代DEHP的潜力。增塑剂的构效关系表明,在相同相对分子质量下分子结构中支链多的增塑剂与PVC之间的相容性和耐抽出性更好,但热稳定性和耐挥发性降低。

A series of bio-based gester plasticizers[glycerol trioctanoate,glycerol tri(2-ethylhexanoate),glycerol trivalericate,glycerol tri(2-methylbutyrate)]were synthesized by direct esterification of glycerol with different fatty acids(octanoic acid,2-ethylhexanoic acid,valeric acid and 2-methylbutyric acid),and then characterized by FTIR and ^(1)HNMR.The plasticizing effects of the prepared plasticizers on polyvinylchloride(PVC)formulations were investigated with commercial plasticizer bis(2-ethylhexyl)phthalate(DEHP)used as control.The results showed that compared with those of the PVC test sheet plasticized by DEHP,the elongation at break of PVC test sheet plasticized glycerol trivalerate was increased by 151.0%,the initial degradation temperature of PVC test sheet plasticized by glycerol trioctanoate displayed an improvement of 12.3℃,and the volatility resistance of the one plasticized by glycerol tri(2-methylbutyrate)was also enhanced,indicating that the obtained plasticizers show the promise to fully or partially replace DEHP.Furthermore,the structure-activity relationship analysis for the plasticizers demonstrated that plasticizers with more branched chains in molecular structure at the same relative molecular mass had better compatibility and extraction resistance with PVC,but with reduced thermal stability and volatility resistance.