Effect of chitosan gelatinization temperature on water absorption and water retention of chitosan-based urea fertilizer

• Main Authors: Mohamad, Noraiham, Abdul Hamid, Nor Nadiah, Abdul Razak, Jeefferie, Dimin @ Mohd Amin, Mohd Fairuz
• Format: Article
• Language: English
• Published: Universiti Malaysia Pahang 2013
• Subjects: S Agriculture (General); TP Chemical technology; TJ Mechanical engineering and machinery
• Online Access: http://eprints.utem.edu.my/id/eprint/11002/2/23_Mohamad%20et%20al.pdf; http://eprints.utem.edu.my/id/eprint/11002/; https://ijame.ump.edu.my/images/Volume_8/23_Mohamad%20et%20al.pdf
• Institution: Universiti Teknikal Malaysia Melaka

Chitosan is highly potential to be blended together in urea fertilizer for slow release properties due to its unique polymeric cationic character and gel forming properties. In agriculture, the slow release properties are normally indicated by the ability of urea fertilizer to absorb and retain water since nitrogen is released to the environment once urea is in contact with water or enzyme. This paper investigates the effect of chitosan content and gelatinization temperature on physical properties of chitosan based urea fertilizer. The chitosan content was varied from 0, 3, 5, 7 and 10 pph. Chitosan based urea fertilizer was prepared through a direct wet mixing using laboratory set up consist of beaker, magnetic stirrer and hotplate. The properties of chitosan based urea fertilizer were compared at two different mixing temperatures which are 60oC and room temperature of 25 ± 3oC. The mixture was then dried in an oven at 60oC for 8 hours before fabricated into pellet using a hydraulic hand presser. Water absorption and water retention analysis were carried out to measure amount of water intakes and amount of water retain in fertilizer. It was observed that mixing temperature has negligible effect on water retention of the fertilizers. However, gelatinization at room temperature resulted in fertilizers with better water absorption and water retention properties than the one gelatinized at 60C. These results were supported by X-Ray Diffraction (XRD) analysis conducted on the fertilizers. As a conclusion, the gelatinization temperature plays important role to improve water retention and water absorption capability of chitosan based urea fertilizers. Furthermore, the presence of chitosan improved crystallinity of urea fertilizers as indicated by XRD analysis.