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Shellac is a kind of ideal natural macromolecule membrane materials due to their good filming and easy-transform. Shellac membrane has been widely applied in various fields, especially in food because of their unique properties such as biocompatibility, biodegrad-ability, good viscidity and certain mechanical strength.Bleach shellac was preparation by several bleach agents base on shellac in this paper. Several effect factors of the bleaching reaction were investigated, including different solvent, react temperature, react time and mixture ratio on bleach reaction for bleaching. An simple and efficient solvent bleach method is achieved, which overcome the defect of the present condition. Based on the ultraviolet spectrophotometer technology,a quantitative token method for shellac was established. By orthogonal experiment and single factor experiment, the optimum technological conditions of bleached reaction was:the amount of bleach agent T is 0.04mol, reaction time is 2h, reaction temperature is 65℃, the concentration of oil of vitriol 5%, it’s B1(62.22)is better than the present Suwell technology (29.67)。The physicochemical characteristics of raw shellac, hypochlorite sodium bleached shellac were studied by the techniques of UV, FTIR, viscosity measurement. Results showed that the special viscosity number of bleached shellac(sample 2.12) is 0.07, the new method bleached shellac effect is better than the present condition and hadn’t changed the basic structure of shellac, the bleached shellac has better stability than traditional hypochl-orite sodium technology.The kinetic property of shellac bleach reaction was investigated by ultraviolet spectro-photometer and the structures of the product were identified by spectral analysis, Effects of react temperature, react time and mixture ratio on bleach reaction were investigated. Results showed that the reaction equation is Rp=0.0219[MA]0.2505[MB]0.1547, the activation energy is 10.25kJ/mol.In the raw shellac, the content of resin is 79.6%, the content of shellac wax is 6.00%, the content of pigment is 0.46%. Estimate the quantity and the quality of shellac wax, pigment from raw shellac with ultraviolet spectrophotometer and FTIR. The FTIR analysis discovers that the component of shellac wax and Suhua shellac wax is almost alike.
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