文档介绍：Controlled-release fertilizer encapsulated by starch/polyvinyl alcohol coating Xiaozhao Han a,b, Sensen Chen a, Xianguo Hu b * aSchool of Chemical Engineering, Hefei University of Technology, 230009 Hefei, People's Republic of China bSchool of Mechanical Engineering, Hefei University of Technology, 230009 Hefei, People's Republic of China Tel. +86 551 290 1359; Fax +86 551 290 2956; email: ******@hfut. Received 22 June 2007; revised 11 January 2008; accepted 18 January 2008 Abstract Encapsulation through polymeric membranes to control the release rate of fertilizers can reduce fertilizer ’ s losses and minimize environmental pollution. A biodegradable starch/polyvinyl alcohol (PVA) blend film for coating the soluble granular fertilizer has been prepared. The influence of the blending ratio of starch/PVA and the content of formaldehyde on the properties of the film has been investigated. The membrane (starch:PVA ? 7:3, crosslinked by formaldehyde content:10 wt%) structure was observed by X-ray diffraction (XRD), Fourier transform infrared absorption spectra (FTIR), and atomic force microscopy (AFM). The XRD results shows that the crystal structure of PVA was changed after being crosslinked with starch, whose vice-bond was broken and crystal was destroyed. The FTIR explores the starch was linked with PVA by chemical binding the crosslinking reaction results in an improvement pati