采用自然环境暴露和田间埋土试验, 利用质量变化、 红外光谱和电镜扫描技术研究自行研发的包膜肥料用改性聚乙烯醇膜材料的降解性。 自然暴露和田间埋土试验结果表明, 研发的膜材料均具有一定的降解性, 且降解率随培养时间增加呈现上升的趋势。 两种试验条件下, 降解率最高的膜材料可达到35%以上, 其中柠檬酸作为改性剂研发的膜材料降解性远远强于环氧树脂作为改性剂研发的膜材料。 柠檬酸/聚乙烯醇/硅藻土复合膜材料因硅藻土的添加使得降解性能进一步增强, 强于未改性的膜材料。 而环氧树脂/聚乙烯醇膜材料虽然有一定的降解性, 但是相较于对照差别不显著, 添加硅藻土之后也不能明显增加其降解率。 红外光谱表征结果显示, 膜降解后一些主要基团CO, CC, CH的数量较对照有所减少, 透射率增强, 这说明膜发生了一定的降解。 电镜扫描结果显示膜降解后表面变粗糙、 凹凸不平, 也说明该膜材料具有一定的降解性。 红外光谱和电镜扫描的结果与质量变化试验的结果相一致, 能够更客观地表征膜材料的降解性。 研发的聚乙烯醇改性后的膜材料既能有效控制养分释放, 又能在自然环境中自行降解, 又不对环境造成危害, 适合作包膜肥料用的膜材料。

Using outdoor exposure and cinnamon soil incubation test, by quality changes, infrared spectroscopy and electron microscopic scanning technology, to research the degradation ability of self-developed coated fertilizer films. The results of outdoor exposure and cinnamon soil incubation test showed that all films had certain degradation ability, and the degradation rate increased with the increase of time. Under two kinds of test conditions, the highest degradation rate could reach above 35%. The degradation ability of film citric acid/PVA was much stronger than epoxy resin/PVA. The degradation ability of citric acid/PVA/diatomite composite film materials was further enhanced because of the addition of diatomite. The epoxy resin/PVA composite film materials, although they had certain degradability, compared to the contrast, the difference was not significant, and adding diatomite can’t obviously increase the degradation rate. The results of IR spectroscopy showed that some major functional groups, such as CO, CC, CH would be reduced after degradation, and the transmission rate also increased, which showed that the degradation of composite film materials must be happened. Scanning electron microscopy showed that the surface becomes rough and uneven, and it also meant the films have some degradation. The results of IR spectroscopy and scanning electron microscopy were consistent with the results of quality change test, and could more objectively represent the degradability of film material. Modified film materials can effectively control nutrient release without causing harm to the soil environment, so it is suitable for the film materials of coated fertilizer.