Study on Modification of UFRA by Enzyme Hydrolysis Prepared Oxidized Starch
In this work, we concentrate on the preparation of oxidized starch modification reagent by enzymatic hydrolysis pretreatment, preparation of the urea-formaldehyde resin with low toxicity. The performance of modified urea-formaldehyde resin depend on the oxidation degree of oxidized starch and whether using enzymatic hydrolysis pretreatment or not. 100-PH9-HOS(the starch enzymatic hydrolysis then oxidized in 100°C with pH 9) synthetized modified urea-formaldehyde resin (100-PH9-HOS-UF) only with a free formaldehyde content of 0.14%, the lowest formaldehyde emission of 0.6078mg/L. Infrared spectroscopy test results show that samples at 3350cm-1 p-hydroxyl hydrogen bonds of association half-peak width minimum hefeng, amino-hydroxy hydrogen bond of association that samples are the weakest and with maximum cross-linking degrees; The modified urea-formaldehyde resin by oxidized starch curing properties of impact factors show that: the deeper drgree of oxidation, the higher curing temperature and the lower enthalpy.