环氧基聚硅氧烷调控制备耐水解结晶聚乙交酯的研究

Controllable preparation of hydrolysis-resistant crystalline poly(glycolic acid)using poly(epoxypropoxy)silsesquioxane

设计合成了环氧基取代的聚硅氧烷(PESQ),以0.5%,1.0%,2.0%及4.0%(质量分数,下同)的浓度与聚乙交酯(PGA)熔融混合,通过对PESQ改性PGA的流变性能、水解性能及结晶性能进行表征,揭示了PESQ改性对PGA带来的影响。结果表明,PESQ以扩链的形式与PGA进行结合,提高PGA复黏度的同时促使其疏水性能的提升,进而改善PGA的水解性能,使得其水解10 d之后的质量损失下降21.1%。此外,PESQ还能促进PGA的结晶,随着PESQ添加量的增加,PGA的结晶温度最高可增至179.5℃,相比于纯PGA的结晶温度172.7℃提升了6.8℃,并且结晶初期的活化能降低,说明PESQ起到了异相成核的作用。

Poly(epoxypropoxy)silsesquioxane(PESQ)was designed and synthesized and then melt blended with poly(glycolic acid)(PGA)at loadings of 0.5 wt%,1.0 wt%,2.0 wt% and 4.0 wt% to prepare the hydrolysis-resistant crystalline PGA.The changes in the rheological,hydrolysis,and crystallization properties of the PESQ-modified PGA was investigated to study the effect of PESQ modification on PGA.The results indicated that a combination of PESQ and PGA in a chain expansion form effectively improved the hydrolytic performance of PGA through increasing its viscosity,resulting in a reduction in the mass loss by 21.1% after degrading for 10 days.Furthermore,PESQ could facilitate the crystallization of PGA.With an increase in the addition amount of PESQ,the crystallization temperature of the modified PGA increased to 179.5℃,which was higher than that of pure PGA by 6.8℃.There is a decrease in the initial crystallization activation energy of the modified PGA,indicating that PESQ contributed to heterogenous nucleation.