| Summary: | 碩士 === 國立臺北科技大學 === 化學工程系碩士班 === 89 === Nowadays, the development of flame retardants has to meet many requirements such as low smoke, non-corrosive, non-toxic and to be ecologically friendly. Because of cost/performance effectiveness, the halogen-containing flame retardant is the most popular choice. Hoeever, halogen-containing polymers generally evolve large amount of smoke and corrosive gases during combustion, and there is a great demand for low smoke and low toxic formulation.
In the study, an intumescent and ecologically friendly fire retardant was prepared from chitosan by phosphorylation reaction. Phosphorylated chitosan was combined with melamine or red phosphorus to improve its flame retardancy. FTIR and 13C NMR spectra of residue char, obtained from TGA analysis of phosphorylated chitosan under air at different temperatures, were used to propose the action mechanism of flame retardant.
The flammability and thermal stability of LDPE blended with phosphorylated chitosan have been investigated with TGA, OI and Cone calorimeter. The results reveal oxygen indices and major thermal degradation temperature of LDPE blends increased with increasing phosphorylated chitosan content. Data from heat release rate measurement and residual char yield analysis indicated that phosphorylated chitosan decompose to function as a condensed phase flame retardant. Plots of polymer surface temperature against time show that the expanded carbon formed in the combustion of phosphorylated chitosan provides a heat insulating effect toward the undecomposed bulk and improve the thermal stability of LDPE.
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