Abstract:
Here, we report the marine degradability of polymers with highly ordered structures in natural environmental water using microbial degradation and biochemical oxygen demand (BOD) tests. Three types of elastic fibers (non-porous as-spun, non-porous drawn, and porous drawn) with different highly ordered structures were prepared using poly[(R)-3-hydroxybutyrate-co-16 mol%-4-hydroxybutyrate] [P(3HB-co-16 mol%-4HB)], a well-known polyhydroxyalkanoate. Scanning electron microscopy (SEM) images indicated that microorganisms attached to the fiber surface within several days of testing and degraded the fiber without causing physical disintegration. The results of BOD tests revealed that more than 80% of P(3HB-co-16 mol%-4HB) was degraded by microorganisms in the ocean. The plastisphere was composed of a wide variety of microorganisms, and the microorganisms accumulated on the fiber surfaces differed from those in the biofilms. The microbial degradation rate increased as the degree of molecular orientation and porosity of the fiber increased: as-spun fiber < non-porous drawn fiber < porous drawn fiber. The drawing process induced significant changes in the highly ordered structure of the fiber, such as molecular orientation and porosity, without affecting the crystallinity. The results of SEM observations and X-ray measurements indicated that drawing the fibers oriented the amorphous chains, which promoted enzymatic degradation by microorganisms.
摘要:
这里,我们使用微生物降解和生化需氧量(BOD)测试报告了具有高度有序结构的聚合物在自然环境水中的海洋降解性。三种类型的弹性纤维(无孔初纺,无孔拉伸,使用聚[(R)-3-羟基丁酸酯-co-16mol%-4-羟基丁酸酯][P(3HB-co-16mol%-4HB)]制备了具有不同高度有序结构的多孔拉伸),一种众所周知的聚羟基链烷酸酯。扫描电子显微镜(SEM)图像表明,微生物在测试的几天内附着到纤维表面并降解纤维而不引起物理分解。BOD测试结果表明,海洋中超过80%的P(3HB-co-16mol%-4HB)被微生物降解。质体由各种各样的微生物组成,并且在纤维表面积累的微生物与生物膜中的微生物不同。微生物降解速率随着纤维的分子取向度和孔隙率的增加而增加:初生纤维<无孔拉伸纤维<多孔拉伸纤维。拉伸过程引起纤维高度有序结构的显着变化,如分子取向和孔隙率,而不影响结晶度。SEM观察和X射线测量的结果表明,拉伸纤维取向的无定形链,促进微生物的酶降解。