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采用马来酸酐封端聚碳酸1,2-环己二酯(PCHC),使其末端羟基转变为端羧基(MA-PCHC),并以2,2’-双-(2-噁唑啉)(BOZ)为扩链剂进行扩链反应.研究发现,BOZ与MA-PCHC中的羧基等摩尔情况下,扩链效果最佳.扩链后的PCHC的数均分子量从扩链前的5.6×104增长到12.4×104.扩链后的PCHC热稳定性能得到了明显的提高,起始热分解温度(Td-5%)由260℃提高到317℃,玻璃化转变温度(Tg)由114℃提高到133℃,而且在凝胶含量没有明显变化的情况下熔体黏度提高了30倍.封端扩链后的PCHC的拉伸强度从普通PCHC的35.81 MPa增加至40.22 MPa,断裂伸长率从4.59%增加至6.22%,而且封端扩链后的PCHC甚至出现了一定的应力屈服的现象.
Maleic anhydride was used to block 1,2-bis (2-oxazoline) -caprolactone (PCHC) to convert its terminal hydroxyl group into terminal carboxyl group (MA-PCHC) (BOZ) as the chain extender.It was found that the chain extension was the best when the molar ratio of BOZ to MA-PCHC was equal to the carboxyl group.The number average molecular weight of PCHC after chain extension was increased from 5.6 × 104 to 12.4 × 104. The thermal stability of PCHC after chain extension has been significantly improved, the initial thermal decomposition temperature (Td-5%) increased from 260 ℃ to 317 ℃, the glass transition temperature (Tg) from 114 ℃ To 133 ℃, and the viscosity of the melt increased 30-fold with no significant change of gel content.The tensile strength of PCHC after capped chain extension increased from 35.81 MPa to 40.22 MPa of ordinary PCHC, and the elongation at break From 4.59% to 6.22%, and the PCHC after the end-capped chain extension even shows some stress yielding phenomenon.