PPC地膜不同覆盖方式下降解特征的红外光谱分析  

Infrared Spectrum Analysis of Degradation Characteristics of PPC Plastic Film Under Different Covering Methods

作　　者：牛岸秋 吴景贵[1] 赵欣宇[1] NIU An-qiu;WU Jing-gui;ZHAO Xin-yu(College of Resources and Environmental Sciences,Jilin Agricultural University,Changchun 130118,China)

机构地区：[1]吉林农业大学资源与环境学院,吉林长春130118

出　　处：《光谱学与光谱分析》2023年第2期533-540,共8页Spectroscopy and Spectral Analysis

基　　金：重大科技专项(20200501003GX)资助。

摘　　要：为解决可降解地膜因降解而发生过早的破裂,研究不同覆盖方式下PPC地膜的稳定性及降解情况。设置了6种田间覆盖方式:单层黑色PPC地膜(SB);单层白色PPC地膜(SW);双层黑色PPC地膜(DB);双层白色PPC地膜(DW);上黑色下白色双层PPC地膜(DBW);上白色下黑色双层PPC地膜(DWB),测定了不同时间段地膜的红外光谱特征、力学性能和分子量,对不同处理下地膜的降解情况做出判断。结果表明,地膜长时间暴露在自然条件下,地膜的韧性变差,分子结构中的主链发生断裂,进而C—H键和C—O键的吸收峰相对强度随时间延长发生下降;由于地膜在水分子和微生物的作用下发生降解进而导致C=O伸缩振动峰和C—O—C反对称吸收峰相对强度出现不同程度的上升。双层地膜因经阳光照射下分子链活跃出现粘连的现象,稳定性明显高于单层地膜,因此双层地膜DWB和DBW处理的官能团吸收峰强度较单层地膜稳定,降解程度相对更缓慢。各处理的分子量和力学性能都呈现下降的趋势,双层地膜处理的分子量、伸拉力强度和断裂伸长率显著高于单层地膜,其中黑白双层地膜DWB处理和DBW处理在30~150 d内的稳定性强于单层地膜,到150 d时,DWB处理和DBW处理的分子键断裂伸长率下降至117.66%~120.39%和151.69%~175.20%,伸拉力强度下降至18.28~13.95和15.35~9.81 MPa;重均分子量为72663和66555 g·mol^(-1),数均分子量为62416和66555 g·mol^(-1)。综合分析说明相比较单层地膜,覆盖黑白双层地膜可以减缓PPC地膜因降解而导致的地膜破裂,延长保水保墒性能的时间,更好地发挥双层地膜的优势。PPC地膜双层覆盖方式经过优化后在作物生育期内可以保持其稳定性,且在作物生育期后又可以像单层地膜一样降解,可在实践中应用,也为PPC地膜在农业生产中的应用提供了理论依据。In order to solve the premature rupture of degradable mulch film due to degradation,the stability and degradation of PPC plastic film were studied under different mulching methods.The six mulching methods in the field were as follow:single-layer black PPC plastic film(SB),single-layer white PPC plastic film(SW),double black PPC plastic film(DB),double-white PPC plastic film(DW),double-layer mulch which upper layer was black and the lower layer was white(DBW),the double layer mulch which upper layer was white and the lower layer was a black(DWB).The infrared spectrum characteristics,mechanical properties and molecular weight of film periods were determined at a different time to judge the degradation of the plastic film under different treatments.The results showed that plastic film was exposed to conditions for a long time,and the toughness of plastic film has become worse.The main chain in the molecular structure was broken,furthermore,the relative intensity of the absorption peak of the C—H bond and C—O bond decreases with the increase of time.Due to the degradation of mulch film under the action of water molecules and microorganisms,the relative intensity of the C=O stretching vibration peak and C—O—C antisymmetric absorption peak increased in different degrees.Due to the adhesion of molecular chain activity under sunlight,the stability of double-layer plastic film was higher than that of single-layer plastic film.Therefore,the decreasing trend of peak intensity for black and white double-layer plastic film DWB and DBW was more stable than that for single mulching film.The degradation degree was more slowly.The molecular weight and mechanical properties of each treatment showed a downward trend.The molecular weight.Tensile strength and elongation at the break of the double-layer plastic film were significantly higher than that of single-layer plastic film treatment.The stability of DWB and DBW treatments was stronger than that for the single mulching film within 30~150 days.The elongation at break and

关 键 词：PPC地膜 双层地膜覆盖 红外光谱特征 降解特征 

分 类 号：S131.1[农业科学—农业基础科学]