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Controlled release of urea encapsulated by Starch - g - poly (vinyl acetate) / Yongsheng Niu in Industrial & engineering chemistry research, Vol. 51 N° 38 (Septembre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12173–12177 Titre : Controlled release of urea encapsulated by Starch - g - poly (vinyl acetate) Type de document : texte imprimé Auteurs : Yongsheng Niu, Auteur ; Hongchun Li, Auteur Année de publication : 2012 Article en page(s) : pp. 12173–12177 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Membrane  encapsulated  urea Résumé : A new type of slow-release membrane-encapsulated urea fertilizer was prepared with starch-g-poly(vinyl acetate) (St-g-PVAc) as a biodegradable carrier material. By solution casting and washing rapidly with water the urea was individually encapsulated within the starch matrix modified by vinyl acetate through in situ graft-copolymerization. St-g-PVAc, which exhibits relatively low swellability, was synthesized by the reaction of starch and VAc in the presence of K2S2O8 as the initiator. The chemical structure of the St-g-PVAc and St-g-PVAc/urea composite film was confirmed by FTIR. The release behavior of urea encapsulated in the films was studied. The experimental results indicated that the introduction of hydrophobic PVAc reduced the swellability of the starch matrix; the urea nitrogen slow-release time can reach 28 h in water. The St-g-PVAc/urea composite films could biodegrade in the soil environment. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301684p [article] Controlled release of urea encapsulated by Starch - g - poly (vinyl acetate) [texte imprimé] / Yongsheng Niu, Auteur ; Hongchun Li, Auteur . - 2012 . - pp. 12173–12177. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12173–12177 Mots-clés : Membrane  encapsulated  urea Résumé : A new type of slow-release membrane-encapsulated urea fertilizer was prepared with starch-g-poly(vinyl acetate) (St-g-PVAc) as a biodegradable carrier material. By solution casting and washing rapidly with water the urea was individually encapsulated within the starch matrix modified by vinyl acetate through in situ graft-copolymerization. St-g-PVAc, which exhibits relatively low swellability, was synthesized by the reaction of starch and VAc in the presence of K2S2O8 as the initiator. The chemical structure of the St-g-PVAc and St-g-PVAc/urea composite film was confirmed by FTIR. The release behavior of urea encapsulated in the films was studied. The experimental results indicated that the introduction of hydrophobic PVAc reduced the swellability of the starch matrix; the urea nitrogen slow-release time can reach 28 h in water. The St-g-PVAc/urea composite films could biodegrade in the soil environment. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301684p