The Study On The Cross-linking & Curing Of Functionalized Vegetable Oils And The Slow/Controlled Release Coating Material

In this paper, the vegetable oils were functionalized with castor oil, linseed oil, soybean oil and tung oil as the raw materials. Its epoxides and maleinized products were prepared. Their composition and structures were investigated. The cross-linking & curing reaction of the functionalized vegetable oils were realized under thermal and microwave environment. The influencing factors of thermal and microwave cross-linking & curing reaction of functionalized vegetable oils and the process of thermal and microwave cross-linking & curing reaction were studied. The reaction rule and characteristic of dynamics of cross-linking & curing reaction of functionalized vegetable oils were also studied by gel content(g.c) determination, FTIR, solution viscosity measurement and DSC. Then the optimum condition and reaction activation energy were determined. At last, the functionalized vegetable oils were applied to coating onto the surface of urea and the characteristic of release was studied.By means of the all study mentioned above, it could be given the perfect conditions of the thermal and microwave cross-linking & curing reaction of functionalized vegetable oils as follow: the epoxides were CEh and LEh, the maleinized products were TMh and LMh, the mole ratio of epoxy group and anhydride was 1:2 to 2:1, thermal curing for 2.5h at 160 °C and microwave curing for 9min at 341W, the g.c of cured product would reached highest, the catalysts TB and BE were effective to the cross-linking & curing reaction, the active reagent was active to microwave cross-linking & curing reaction. It was also found that the viscosity under solution reaction in functionalized vegetable oils system were increased as the reaction time prolonged, solution concentration increased, reaction temperature increased. And the catalysts TB and BE were effective to the cross-linking reaction in solution. FTIR results of the curing process shown that characteristic absorbance of anhydride was disappeared along with the cross-linking reaction carried out. DSC results shown that the exothermic -AH was 127.4 kJ/g, the activation energy was 65.8 kJ/mol without catalyst in CEh+TM_h system and the exothermic -AH was 136.1 kJ/g, the activation energy was 32.6 kJ/mol with TB in CEh+TM_h system respectively. The exothermic -AH was 60.9 kJ/g, the activation energy was 11.5kJ/mol with TB in LEh+LMh system. The exothermic -AH was 6.7 kJ/g, the activation energy was 10.7kJ/mol without catalyst in SEh+SMh and the exothermic -AH was 142.1 kJ/g, the activation energy was 7.9 kJ/mol with TB in SEh+SMh system respectively. The result of characteristic of release indicated that the release rate slowed and the characteristic of slow release improved as the thickness of coating layer increased.