红外光谱分析丙烯酸树脂包膜尿素膜降解特征

摘要

The degradability characteristics of film with 4 kinds of methyl methacrylate coated urea amended with inhibitors were analyzed by FITR, which was purposed to supply theoretical basis for applying the FITR analysis method to film decomposition and methyl methacrylate coated urea fertilizers on farming. The result showed that the chemical component, molecule structure and material form of the membrane were not changed because of adding different inhibitors to urea, the main peaks of expressing film degradation process were brought by the -C- H of CH3 & CH2, -OH, C-O, C-C, C-O-C, C=O , C=C flexing vibrancy in asymmetry and symmetry in 3 479~3 195, 2 993~2 873, 1 741-1 564, 1 461~925 and 850~650 cm"1. The peak value changed from smooth to tip, and from width to narrow caused by chemical structural transform of film. The infrared spectrum of 4 kinds of fertilizers was not different remarkably before 60 days, and the film was slowly degraded. But degradation of the film was expedited after 60 days, it was most quickened at 120 day, and the decomposition rate of film was decreased at 310 day. The substantiality change of film in main molecule structure of 4 kinds of fertilizers didn't happen in 310 days. The main component of film materials was degraded most slowly in brown soiL The speed of film degradation wasn't heavily impacted by different inhibitors. The characteristic of film degradation may be monitored entirely by infrared spectrum. The degradation dynamic, chemical structure change, degradation speed difference of the film could be represented through infrared spectrum.%采用傅里叶变换红外光谱吸收(FTIR)方法分析丙烯酸树脂包膜尿素及与生化抑制剂结合的四种肥料在棕壤中膜降解特征,尝试利用红外光谱技术分析丙烯酸树脂膜降解特征,为包膜尿素肥料的应用提供科学依据.分析表明,成膜的化学成分,分子结构和膜组成没有因不同种生化抑制剂的加入而受到影响.膜特征峰出现在3479～3195,2993～2873,1741～1564,1 461～925和850～650cm-1之间,主要是CH3,CH2的-C-H,-OH,C-O,C-C,C-O-C,C=O,C=C的不对称、对称伸缩振动吸收,峰面随时间变化由平到尖,由宽到窄,吸收强度因化学键量变强弱不一.60 d前四种肥料膜红外吸收光谱没有明显区别,膜降解缓慢；而60 d后降解速度加快,以120 d降解速度最快,310 d后四种肥料膜主要分子结构没有实质性改变,膜材料主要成分在棕壤中降解十分缓慢,降解速度并没有明显受到不同生化抑制剂的影响.降解特征可以用红外吸收光谱测定与描述,红外光谱能够描绘膜降解动态,物质化学基团变化,降解速度的差别.