摘要
尿素醛(UF)缓释氮肥作为一种缩聚物,结晶度较高,微生物降解缓慢,导致养分缓释周期过长,典型的倒“L”形养分释放率曲线,与大多数农作物的生长规律不符。采用生长调节剂腐植酸(HA)对UF改性,以调整UF的养分释放周期,使其的养分释放与作物生长所需规律更匹配。首先,改性HA,以使预交联腐植酸(CHA)的羟基相较HA大幅提升;随后,与羟甲基脲(MU)发生脱水缩合反应,使MU接枝到CHA表面;最终通过连续自缩聚和接枝反应生成腐植酸/尿素醛(CHAUF)材料,构建了均匀孔隙的网络结构及合适分子链长。并且研究了不同成分的含量和反应条件对其缓释性能的影响,最终实现良好且可调控的缓释性能。傅里叶变换红外光谱(FTIR)和热重分析(TG)表明CHA已被成功改性。扫描电子显微镜(SEM)表明,该材料具有良好且均匀的网络结构。优化氮养分释放的规律为前期养分释放较少,中后期养分释放加快的“S形”释放曲线,更匹配作物生长所需。
Urea aldehyde(UF)released nitrogen fertilizer slowly,as a polycondensate,had high crystallinity and slow microbial degradation,which led to long nutrient slow-release cycle.The typical inverted L-shaped nutrient release rate curve was inconsistent with the growth law of most crops.Growth regulator humic acid(HA)was used to modify UF,so as to adjust the nutrient release cycle of UF and made its nutrient release more match with the law required for crop growth.Firstly,HA was modified to increase the hydroxyl group of pre-crosslinked humic acid(CHA)significantly comparing with HA.Subsequently,CHA and hydroxymethylurea(MU)occurred dehydration condensation reaction,and MU was grafted to the surface of CHA.Finally,humic acid/urea aldehyde(CHAUF)material was generated by continuous self-condensation and grafting reaction,and the uniform pore network structure and appropriate molecular chain length were constructed.The effects of the contents of different components and reaction conditions on the slow-release properties were studied.The slow-release properties were achieved with good and controllable performance.Fourier transform infrared spectroscopy(FTIR)and thermogravimetric(TG)analysis indicates that the CHA has been successfully modified.Scanning electron microscope(SEM)shows that the material has a good and uniform network structure.The nutrient releasing in the early stage is reduced,and the nutrient releasing in the middle and late stage is accelerated.The law of nitrogen nutrient release is optimized as“S shape”,so that it can better match the needs of crop growth.
作者
郭蕴慧
刘亚青
GUO Yunhui;LIU Yaqing(Shanxi Key Laboratory of Nano-functional Composites,College of Materials Science and Engineering,North University of China,Taiyuan 030051,China)
出处
《塑料工业》
CAS
CSCD
北大核心
2023年第6期182-190,共9页
China Plastics Industry
基金
中央引导地方科技发展资金项目(YDZJSX2021B007)
山西省高等学校科技创新项目资助(2019L0585)
山西省应用基础研究计划项目(201901D211273)。
关键词
改性腐植酸
尿素醛
网络结构
缓释性能
Modified Humic Acid
Urea Aldehyde
Network Structure
Slow Release Performance
作者简介
郭蕴慧,女,1995年生,在读硕士生,主要从事生物降解材料的研究。18434365443@163.com;通信作者:刘亚青,女,1970年生,教授,主要从事生物降解材料的研究。lyq@nuc.edu.cn。
