光氧化TiO_2/PEO/LDPE复合薄膜的生物降解性能  

Biodegradation of photo-degraded mulching films based on polyethylenes containing polyethylene oxide modified TiO_2 as pro-oxidant additives

作　　者：杨薇[1] 杨玉鹰 蔡亦金 张桂乔 罗颖[1] 

机构地区：[1]华南农业大学材料与能源学院,广州510642

出　　处：《功能材料》2016年第4期105-109,共5页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(51003034;21271074);广东省科技计划资助项目(2014A010105038);华南农业大学校长基金资助项目(4900-K09189);华南农业大学"211工程"三期重点建设资助项目(2009B010100001)

摘　　要：以聚氧乙烯(PEO)为亲水改性剂、纳米TiO_2颗粒作为光催化助氧剂,与低密度聚乙烯(LDPE)树脂复合制备了光氧化-生物降解TiO_2/PEO/LDPE纳米复合薄膜。通过密封堆肥和土壤微生物的降解实验,研究了该复合薄膜在空气中紫外光氧化降解后的生物降解性能。结果表明,TiO_2/PEO/LDPE复合薄膜在UVA340的紫外光照射600h后,发生了明显的降解,羰基指数增大,产生了大量羰基类的化合物,结构发生明显的破坏;光氧化后的薄膜碎片经过180d的堆肥或254d的土壤微生物降解后,其矿化率达到15.26%,薄膜表面长满了孢子及大量的菌丝,能够为微生物的生长提供所需的碳源。PEO的加入能提高纳米TiO_2在LDPE基体中的亲水性,从而提高其光催化氧化活性,使得LDPE薄膜的光氧化降解程度明显增大,有利于其后续的生物降解。The photodegradable TiO_2/PEO/LDPE composite film was prepared by an addition of TiO_2 as a prooxidant containing polyethylene oxide(PEO)into commercial LDPE.The biological mineralization in a seal composting environment and microbial degradation of oxidized LDPE were studied.The results show that the intensities of carbonyl group peak in the TiO_2/PEO/LDPE composite film with exposed to UVA340 irradiation for 600 hincreased would be due to ester,acid and aldehyde compounds,which were produced by LDPE degradation,increased in films and the structure of TiO_2/PEO/LDPE composite film destroyed clearly.The TiO_2/PEO/LDPE composite films with pro-oxidant exposed to UV irradiation followed by compost for 180 days or soil microbial degradation for 254 days.In this process,the mineralization rate of TiO_2/PEO/LDPE composite film reached 15.26%.On the other hand,microscopic examination showed a profuse mycelia growth and spores on the oxidized TiO_2/PEO/LDPE composite films,which illustrated that the soil microbial were fully capable of utilizing degradation products as a carbon source.The addition of PEO improves the hydrophilicity of nanoTiO_2 in LDPE matrix,thus the photocatalytic degradation efficiency increases facilitating the oxo-degradation of LDPE greatly which promotes the subsequent biodegradation.

关 键 词：聚氧乙烯 亲水改性剂 纳米TIO2 低密度聚乙烯 生物降解 

分 类 号：TQ325.2[化学工程—合成树脂塑料工业]