Study On Polyacrylamide And Multiple Slow Released Fertilizer By Electrochemistry

Slow released fertilizer, with excellent water and nutrients keeping properties, is widely used in the agriculture. But the high cost and complex process restricted its widespread application. So we assume that it is feasible to use a simple method and some cheap raw materials. With easy process and less pollution, the method of electrochemical was chosen. Polyacrylamide (PAM) was used to be carrier. Urea and KH2PO4were used as raw materials.In this paper, a new synthesis method of slow released fertilizer was discussed. Acrylamide was copolymerized to form the carrier of the slow released fertilizer. The urea and KH2PO4was grafted on the carrier to provide plant nutrition. A new style fertilizer which contained nitrogen, phosphorus and potassium element was prepared. The product was discussed by infrared spectroscopy (IR), TG and the cyclic voltammetry curves (CV). The mechanism of the electrochemical synthesis of PAM was investigated and the reaction course was determined. The content of the nitrogen, phosphorus and potassium was tested. The results can be described as follows:1、The best preparing technological parameters of PAM were obtained: ω(AM)=9%, co(Ce4+)=0.8%,I=0.25A·cm-2. The molecular weight of polyacrylamide was1.87million and it can be reached a conversion rate of76.3%.2、For the preparation of fertilizer, the best amount of raw material were: ω(Urea)=7.2%, ω(KH2P04)=5.4%。A slow released fertilizer was obtained with contents of nitrogen, phosphorus and potassium were32.5%,13%,13%, respectively. When it was used to simulate the soil release situation, a60day’s releasing period was obtained. The field experiment proved that it can increase8.19%to vegetables.3、Three factors at four levels orthogonal experiment table was designed. Conclude that:the influence of each factor for conversion rate was ω(AM)> ω(Ce4+)> I, the influence for molecular weight was co(AM)>I>ω(Ce4+). In all of these factor, the concentration of AM was the most significant.4、The FT-IR shown that acrylamide and acrylic acid can be polymerized to Poly (AM-co-AA) by electrochemical polymerization. The Urea was successfully grafted to the polymer by electrochemical.5、the cyclic voltammetry curves shown that there were grate number of free radicals at the electrochemical polymerization system under the effects of both cerium Ce4+and electrochemical method. The oxidation peak was appeared at1.6V. And in this process, Ce4+was cycling use.6、It was concluded that the anodic and the cathodic apparent transport coefficient were both one. The reaction order of Ce4+was one. The determining step in the electrochemical synthesis process was obtained. It was the third process, that is:...