甲醛交联木质素季铵盐--尿素的制备及缓释性能

为了探究木质素季铵盐包埋尿素的优化制备条件及其在缓释肥生产中的应用,以三甲基木质素季铵盐(L-QA)为原料、甲醛为交联剂、司盘80为分散剂,采用反相悬浮法制备甲醛交联木质素季铵盐-尿素(FCL-QA-U)颗粒,并通过傅里叶红外光谱表征其结构,探讨交联剂用量、转速、反应时间和分散剂用量等因素对尿素包埋率的影响,以得到最佳制备工艺条件及产品,再利用水溶试验和土柱淋溶试验测定其缓释性能。结果表明: 尿素被包埋在三甲基木质素季铵盐中;L-QA含氮量为1.98%,FCL-QA-U含氮量为3.27%。制备FCL-QA-U颗粒的最佳工艺条件为甲醛用量2 mL、转速300 r/min、反应时间2 h、司盘80用量1 mL,在此条件下制备的FCL-QA-U颗粒的尿素最大包埋率为64.77%。 FCL-QA-U颗粒的缓释结果符合我国缓释肥料GB/T 23348—2009的要求,是一种既有理论价值又有应用价值的缓释化肥。 

Synthesis and slow-release performance of formaldehyde crosslinked lignin quaternary ammonium salt-urea

In order to explore the optimal conditions for the synthesis of lignin ammonium salt embedding urea and its application in the slow-release fertilizer production, formaldehyde crosslinked lignin quaternary ammonium salt-urea ( FCL-QA-U ) was synthesized using reversed phase suspension polymerization technique with trimethyl lignin quaternary ammonium salt based on lignin ( L-QA) as the raw material, formaldehyde as the crosslinking agent, and Span 80 as the dispersing agent. Its structure was analyzed by FT-IR. The effects of the dosage of crosslinking agent, rotating speed, reaction time,and the dosage of dispersing agent on the embedding rate of urea were studied for obtaining the optimal process conditions and product. Then slow-release performance was measured with the methods of water solving and soil column leaching. The results showed that urea was embedded in the L-QA, of which nitrogen content was 1. 98%, and nitrogen content of FCL-QA-U was 3. 27%. The optimal process conditions of FCL-QA-U were:the dosage of formaldehyde 2 mL, reaction time 2 h, rotating speed 300 r/min, and the dosage of dispersing agent 1 mL. Under the optimal conditions, the maximum embedding rate of urea by FCL-QA-U particles was 64. 77%. The slow-release performance of FCL-QA-U particles accorded with the national standard of slow-release fertilizer GB/T 23348—2009 , and it is a kind of slow-release fertilizer having both theoretical and also application value.