环境降解地膜的热降解特性探究

Exploration of Thermal Degradation Characteristic of Environmental Degradable Mulching Film

在低密度聚乙烯中添加热敏剂NiCoMnO4、NTC制备热降解地膜,通过断裂伸长率保留率、热分析、红外光谱测试,研究了热敏剂对聚乙烯地膜降解特性的影响。研究结果表明,地膜在NiCoMnO4、NTC添加量为0.5%~0.6%,温度为40℃~50℃时降解效果较好,断裂伸长率保留率分别在处理42d和60d后降低到10%以下。红外分析表明,2种地膜在处理过程中主要发生了氧化降解反应,在1717cm-1范围羰基区出现吸收峰,并随时间的延长和温度的升高越来越强。差示扫描量热分析发现,NiCoMnO4、NTC地膜的结晶度在处理60d后分别增加2.9%~6.45%和0.89%~3.48%,意味着地膜的热降解主要发生在分子链间距较大的非晶区。

Thermal degradation mulching film was prepared by adding thermal catalyst NiCoMnO4,negative temperature coefficient(NTC)in the low density polyethylene.The thermal degradation was studied by the retention rate of elongation,thermal analysis,infrared spectrum,analyzed in the process of thermal degradation of catalyst changes in mechanical properties and molecular structure.The result indicate that the degradation effort of environment degradation plastic at 40℃~50℃is good with adding NiCoMnO4 and NTC of 0.5%~0.6%,and the retention rate of elongation drops below 10%after 42 dand 60d,respectively.The testing result of IR spectrum indicates that the oxidation degradation reaction happens in the thermal treatment process.And it shows that a peak which is more stronger with increasing of time and temperature at 1717cm-1 is carbonyl absorption peak area.The testing results of DSC indicate that the crystallinity of NiCoMnO4 and NTC mulching film increases by 2.9%~6.45% and 0.89%~3.48%respectively after processing 60 d,that means the thermal degradation happens in the amorphous area of spacing of larger molecular chain.