聚丁二酸丁二醇酯生物降解性能研究

Biodegradability of Poly( Butylene Succinate)

目的研究酶解与水解对聚丁二酸丁二醇酯(PBS)生物降解性能的影响。方法将PBS薄膜分别置于酶液与磷酸缓冲液中进行酶解与水解试验,利用热失重分析(TG)、X射线衍射(X-RD)、扫描电镜(SEM)以及失重率等测试手段或指标,对材料的生物降解性能进行表征。结果 TG与X-RD的测试结果表明,酶解后材料的热稳定性下降,热分解温度由308.83℃降低到282.85℃,同时材料的结晶度呈现一定程度的下降。水解后材料的热稳定性呈现出先降低再升高的趋势,而结晶度则基本维持不变。SEM与失重率结果证实,PBS的酶解主要通过表面侵蚀的方式进行,材料的失重率呈线性增长的趋势,降解10周后失重率约为33.2%;而水解则主要以整体侵蚀的方式进行,材料的失重率变化并不明显,降解20周后失重率仅为4.7%。结论 PBS的酶解与水解是2个截然不同的过程,酶解是表面侵蚀,而水解则是整体侵蚀。

Objective To investigate the influence of enzymatic and hydrolytic degradation on the biodegradability of PBS. Methods PBS films were placed in the enzyme solution and phosphate buffer solution for enzymatic degradation and hydrolytic degradation. Biodegradability of PBS was studied by means of thermogravimetry （TG）, X-ray diffraction （X-RD）, scanning electron microscopy （SEM） and weight loss rate. Results TG and X-RD analysis showed that the thermal stability of PBS was reduced from 308.83 ℃ to 282.85 ℃, and the erystallinity of PBS presented a certain degree of decline after enzymatic degra- dation, while the thermal stability of PBS first decreased and then increased during the hydrolytic degradation period and the crystallinity of PBS remained unchanged. SEM and weight loss results confirmed that the enzymatic degradation occurred at the surface of the PBS film and the weight of film decreased with time, the weight loss was 33.2% after 10 weeks of degradation. However, hydrolytic degradation of films occurred throughout the whole polymer matrix and the weights of PBS films did not change significantly, the weight loss was only 4.7% after 20 weeks of degradation. Conclusion The enzymatic degradation was quite different from the hydrolytic degradation. Enzymatic degradation underwent surface erosion while hydrolytic degradation showed bulk erosion.