生物可降解塑料PBAT/PLA在典型非生物降解环境下的降解  

Degradation of biodegradable plastic PBAT/PLA under typical non-biodegradable environment

作　　者：郑涵月 孙姣霞[1] 向红 周瑶 蒋晖[1] 樊建新[1] ZHENG Han-yue;SUN Jiao-xia;XIANG Hong;ZHOU Yao;JIANG Hui;FAN Jian-xin(School of River and Ocean Engineering,Chongqing Jiaotong University,Chongqing 400074,China)

机构地区：[1]重庆交通大学河海学院,重庆400074

出　　处：《中国环境科学》2023年第8期4247-4254,共8页China Environmental Science

基　　金：重庆市自然科学基金资助项目(cstc2020jcyj-msxmX0928);国家自然科学基金资助项目(41977337)。

摘　　要：选用生物可降解塑料聚己二酸对苯二甲酸丁二醇酯/聚乳酸(PBAT/PLA)作为主要研究对象,传统塑料聚乙烯(PE)作为对比材料,在两种典型非生物降解环境下,通过紫外光照(UV)和机械磨损(MA)降解9个月.利用扫描电子显微镜-能谱仪、静态水接触角、吸水性变化和重量损失分析两种塑料理化性质变化,并通过总有机碳测定法分级表征降解产物质量及各自占比情况.结果表明:在UV和MA条件下,PBAT/PLA较PE在表面形貌、碳氧比、吸水率、质量损失等方面均随时间表现出更大的变化,其中UV条件下更为明显,在3月、6月和9月的质量损失率分别达到了3.5%、6.2%和17.9%,表明PBAT/PLA有更强的被降解能力,对UV辐射更敏感.通过降解产物分析发现,PBAT/PLA降解产物的质量大于PE,PE主要产生大于0.22μm的微塑料(MPs),而PBAT/PLA在UV条件下主要产生小于0.22μm的降解产物,在3个月、6个月和9个月质量占比分别为83.8%、87.2%和79.4%,并有部分可能最终降解产生挥发性物质;在MA条件下,PBAT/PLA与PE类似,产生更多大于0.22μm的MPs,在3月、6月和9月质量占比分别为100%、91.2%和81.7%.The biodegradable plastic poly(butylene adipate-co-terephthalate/poly(lactic acid)(PBAT/PLA)and the traditional plastic polyethylene(PE)were degraded for 9months under two typical non-biological degradation conditions,ultraviolet light(UV)and mechanical abrasion(MA).The physical and chemical properties of two kinds of plastics were analyzed by scanning electron microscope-energy spectrometer(SEM-EDS),static water contact angle,water uptake ratios and weight loss.And the quality and proportion of degradation products with different particle size were characterized by total organic carbon(TOC)assay.The results showed that PBAT/PLA exhibited greater changes in surface morphology,oxygen carbon ratio,water absorption and mass loss than PE under both UV and MA conditions.Especially under UV conditions,the quality loss rates in March,June and September reached 3.5%,6.2%and 17.9%,respectively.Degradation product analysis showed that the quality of degradation products of PBAT/PLA were much higher than those of PE.And PE mainly produced microplastics(MPs)larger than 0.22μm,while PBAT/PLA mainly produced degradation products smaller than 0.22μm under the UV condition.In March,June and September,the proportion of mass was 83.8%,87.2%and 79.4%,respectively.Some of the degradation products may eventually degrade to produce volatile substances.Similar to PE,PBAT/PLA produced more MPs larger than 0.22μm under the MA condition.In March,June and September,the proportion of mass was 100%、91.2%和81.7%,respectively.

关 键 词：生物可降解塑料 紫外光照 机械磨损 降解产物 微塑料 

分 类 号：X703[环境科学与工程—环境工程]