PPDO/OMMT纳米复合材料在微生物环境下的降解行为  

BIODEGRADATION BEHAVIORS OF POLY(p-DIOXANONE)/ORGANO-MONTMORILLONITE NANOCOMPOSITES

作　　者：李辉章[1] 庞道林[1] 赖承钺[1] 李方[1] 汪秀丽[1] 王玉忠[1] 

机构地区：[1]四川大学化学学院环保型高分子材料国家地方联合工程实验室,成都610064

出　　处：《高分子学报》2011年第6期633-638,共6页Acta Polymerica Sinica

基　　金：国家杰出青年科学基金(基金号50525309)资助课题

摘　　要：采用微生物水性培养液降解实验法对聚对二氧环己酮/有机蒙脱土(PPDO/OMMT)纳米复合材料的生物降解性能进行了研究.通过质量、特性黏数、pH、热分析和电子扫描显微镜(SEM)研究了试样的降解过程.结果表明,在本实验条件下,PPDO/OMMT纳米复合材料降解性随着OMMT含量的增加而增加.降解90天,在微生物水性培养液中PPDO和含有5%OMMT的纳米复合材料的质量损失率分别为17.9%和28.4%,而在无菌培养液中它们的质量损失率分别为12.9%和18.0%.在微生物培养液中PPDO和PPDO/OMMT的特性黏数都随着降解时间的延长而下降,并且在30天内特性黏数下降的幅度最大.研究表明PPDO和PPDO/OMMT降解过程中水解占主导作用,而微生物产生的酶对降解有促进作用;降解优先发生在非晶区,结晶度随之增加,随后结晶区被降解,结晶度下降;降解后的试样表面有明显被微生物侵蚀的痕迹.The biodegradation behaviors of poly（p-dioxanone）/organo-montmorillonite（PPDO/OMMT） nanocomposites were investigated in an aqueous medium with spores of selected culture microorganisms at 28℃ for 90 days.The degradation of samples was characterized by mass loss,intrinsic viscosity variation,pH value,DSC and SEM.The results showed that the biodegradation rates of nanocomposite increased with the increase of OMMT contents.After 90 days degradation,the weight losses of pure PPDO and PPDO/5% OMMT nanocomposite in the aqueous medium with and without spores of selected culture microorganisms were 17.9%,28.4%,and 12.9%,18.0%,respectively.The biodegradation of PPDO/OMMT was mainly related to the hydrolysis degradation and was improved by selected culture microorganisms.During 30 days of degradation,the intrinsic viscosity of PPDO/OMMT nanocomposites decreased significantly and their weight losses increased slowly as a consequence of the random break of ester bonds in PPDO long chains.As the biodegradation proceeds,many kinds of water-soluble products such as organic acids and oligomeric acids were produced.Therefore,the pH value of aqueous medium decreased and the weight losses increased obviously with the progress of biodegradation.The biodegradation of samples occurred preferentially in the amorphous areas,leading to the increase of crystallinity.As the biodegradation time increased,the crystalline regions were attacked,which caused the decrease of crystallinity.After biodegradation,the remarkable erosion was found on the surface of PPDO due to the bio-erosion of microorganism.However,no remarkable cracks emerged on the surface of PPDO/5% OMMT nanocomposite,which was assigned to the interaction and adhesion of PPDO and OMMT.

关 键 词：聚对二氧环己酮(PPDO) 有机蒙脱土(OMMT) 生物降解 水性培养液 特定微生物 

分 类 号：TB383.1[一般工业技术—材料科学与工程]