植物油基聚氨酯包膜肥料研究进展

Research progress of plant oil-based polyurethane coated fertilizer

缓释肥包膜材料采用的聚氨酯主要由石油基原料制备,由于石油基聚氨酯成本高、环境风险较大,近年来逐渐被生物基聚氨酯所取代。在众多的生物基材料中,植物油因价格低廉、来源广泛、无毒性、可生物降解等特点,成为缓控释肥料膜材的研究热点。本文分别综述了植物油基多元醇的制备方法,植物油基聚氨酯包膜的分类,植物油基聚氨酯包膜肥料的改性及应用。环氧开环、酯交换反应、氨解法、加氢甲酰化以及臭氧氧化还原是植物油改性制备植物油基多元醇的常用技术手段。丙烯酸酯、环氧树脂、有机硅、氟改性、纳米材料等是植物油基聚氨酯包膜材料改性的常用原料,试验证明植物油基聚氨酯包膜肥料具有减少氨挥发、氮淋溶,提高氮素利用效率的作用。如何提高植物油基聚氨酯交联密度、降低生产成本、深入揭示缓释机理以及扩大在大田试验的应用场景将是今后研究的重点。

Polyurethanes,the conventional coating materials used for slow-released fertilizer production,are mainly processed from petroleum-based raw materials.As the high cost and environmental risks of petroleum-based polyurethanes,bio-based polyurethanes have become the alternative coating materials in recent years.Among various bio-based materials,vegetable oil draws attention because of low price,wide source,non-toxicity and biodegradability.In this paper,we summarized the preparation methods of vegetable oil based polyols,the main categories of plant oil based polyurethane coating materials,the modification and application of slow release fertilizers coated with the plant oil based polyurethanes.The often used technologies for the procession of vegetable oil based polyols included epoxy ring-opening,transesterification,ammonolysis,hydroformylation and ozone REDOX.Such raw materials like acrylic ester,epoxy resin,silicone,fluorine modification,nanomaterials,etc.are often used for the modification of plant oil-based polyurethane coating films.Plant oil-based polyurethane coated fertilizer have been proved of advantages of reducing ammonia volatilization and nitrogen leaching,and improving nitrogen use efficiency.How to improve the degradability of plant oil-based polyurethane coating materials and the slow release capacity of fertilizer,increasing the crosslinking density of plant oil-based polyurethane,reduce the production cost,reveal the slow release mechanism and expand the application scenarios in the field trail are the focus of future research.