基于天然多糖缓释肥料的研究

发布时间：2018-03-09 19:01

本文选题：水凝胶　切入点：缓释性能　出处：《河南工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：化肥和水在粮食增产中发挥着重要作用。为了提高肥料和水资源的利用率,人们开发了一系列的保水缓控释肥料。然而,肥料的环境友好性及成本仍是制约其广泛应用的重要因素。由于纤维素、淀粉等天然多糖具有来源广泛、可生物降解等特点,在保水缓释肥料中的应用研究格外引人注明。本论文以颗粒尿素、磷酸二氢钠、氯化钾为化肥原料,吸水保水而又不溶解于水的高分子聚合物水凝胶为载体,制备出了多功能保水缓控释肥料,以提高氮肥利用率、减少环境及食品污染、节约水资源、节省经济成本。本论文主要包括以下四方面的工作。(1)分别用双烯体马来酸糠酰胺(SFA)与亲双烯体N-丙氨酸基马来酰亚胺(AMI)对羟乙基淀粉进行修饰,将得到的产物溶解于水中,加入单体N-异丙烯丙烯酰胺、交联剂N,N-亚甲基双丙烯酰胺及光引发剂,依次通过Diels-Alder点击反应(DA反应)及光聚合反应原位形成互穿网络水凝胶,对水凝胶的结构与性能进行了一系列表征,将其用作肥料控释载体,研究水凝胶的组成、结构、性能与肥料释放动力学之间的规律,为其进一步应用奠定理论基础。(2)采用氢氧化钠-尿素体系低温溶解纤维素棉短绒木浆,加入不同比例丙烯酰胺、氯化钾、交联剂及氧化还原引发剂,通过自由基聚合形成纤维素接枝聚丙烯酰胺的水凝胶,将其作为亲水性肥料内核。以30%松香溶液为粘合剂,将乙基纤维素粉末包裹在内核表面,作为疏水外包膜,制备出内层亲水、外层疏水的缓释肥料,对其性能进行表征,并测定其缓释性能。(3)采用丙烯酸为单体、N,N-亚甲基双丙烯酰胺为交联剂,过硫酸铵及抗坏血酸为氧化还原引发体系,尿素、磷酸二氢钠、氯化钾为植物所需综合营养元素,将其溶解于水中,然后在得到的水溶液中加入纤维素棉短绒粉末,分散均匀后升温到50℃经过自由基聚合形成纤维素接枝丙烯酸的复合水凝胶,将其作为亲水肥料内核。同样以30%松香溶液为粘合剂,将乙基纤维素粉末包裹在内核表面形成疏水外包膜,制备出内层亲水,外层疏水的缓释肥料,对其性能进行表征,并测定其缓释性能。(4)将一定比例的丙烯酰胺、丙烯酸为单体,N,N-亚甲基双丙烯酰胺为交联剂、过硫酸铵及抗坏血酸为氧化还原引发体系,尿素、磷酸二氢钠、氯化钾为肥料,将其溶解于水中,混合均匀后升高温度,经自由基聚合得到纤维素接枝聚丙烯酰胺丙烯酸的水凝胶,干燥后以其作为亲水肥料内核。同样以30%松香溶液为粘合剂,将乙基纤维素粉末包覆在亲水肥料表面,作为疏水外包膜,制备出内层亲水、外层疏水的缓释肥料,对其性能进行表征,并测定其缓释性能。
[Abstract]:Fertilizer and water plays an important role in food production. In order to improve the utilization rate of fertilizer and water resources, people have developed a series of water retention controlled-release fertilizers. However, environmental friendliness and cost of fertilizer is still an important factor restricting its application. Because of the cellulose, starch and other natural polysaccharides have a wide range of sources, biodegradable and other characteristics, application of fertilizers in the particularly eye-catching. In this paper, granular urea, sodium dihydrogen phosphate, potassium chloride as fertilizer raw materials, polymer hydrogel water absorbent and dissolved in water as the carrier, prepared multifunctional SRWAFs controlled-release fertilizer in order to improve the utilization rate of nitrogen fertilizer, reducing environmental pollution and food, conservation of water resources, save the economic cost. The paper mainly includes the following four aspects. (1) respectively with dienophile maleic acid amide bran (SFA) and dienophile N- alanine Acidyl maleimide (AMI) modified hydroxyethyl starch, the product will be dissolved in water, adding N- isopropyl acrylamide monomer, crosslinker N, N- methylene bis acrylamide and photoinitiator, followed by Diels-Alder click reaction (DA reaction) and photopolymerization of in situ formation of IPN hydrogels, structure and the properties of hydrogels were characterized, which is used as fertilizer and controlled release carrier, composition, structure and properties of hydrogels, fertilizer release kinetics between rules and lay a theoretical foundation for its further application. (2) using sodium hydroxide urea system of low-temperature dissolution of cellulose with cotton linter pulp, adding different proportion of acrylamide, potassium chloride, a crosslinking agent and a redox initiator by free radical polymerization to form cellulose grafted polyacrylamide hydrogel as the hydrophilic fertilizer with 30% rosin solution kernel. As a binder, ethyl cellulose powder wrapped in the surface of the inner core, as a hydrophobic outer envelope, prepared by the inner hydrophilic, hydrophobic outer slow-release fertilizer, characterized, and determine its release properties. (3) using acrylic acid as monomer, N, N- methylene bis acrylamide as crosslinking agent, persulfate ammonium and ascorbic acid as redox initiator, urea, sodium dihydrogen phosphate, potassium chloride as the plant needs comprehensive nutrition, will be dissolved in water, then add the powder in cotton linter cellulose obtained in water solution, uniformly dispersed after heating to 50 DEG C to form composite hydrogel polymerization of acrylic acid grafted cellulose by free radicals, as fertilizer. Same with 30% hydrophilic kernel rosin solution as adhesive, ethyl cellulose powder wrapped in kernel is formed on the surface of hydrophobic outer membrane, prepared inner hydrophilic, hydrophobic outer slow-release fertilizer, on the Can characterize, and determine its release properties. (4) a certain proportion of acrylamide, acrylic acid as monomer, N, N- methylene bis acrylamide as crosslinking agent, ammonium persulfate and ascorbic acid as redox initiator, urea, sodium dihydrogen phosphate, potassium chloride fertilizer, it will dissolve in water temperature mixing after obtained by free radical polymerization of acrylic acid grafted cellulose polyacrylamide hydrogel, after drying as the hydrophilic fertilizer kernel. Same with 30% rosin solution as adhesive, ethyl cellulose powder coated fertilizer in the pro surface of the material as a hydrophobic outer envelope, prepared by the inner hydrophilic, hydrophobic outer slow-release fertilizer, to characterize its performance, and determine its release performance.

【学位授予单位】：河南工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ449.1

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