Preparation of Macromolecular Intumescent Flame Retardant Based on Modified Polyurethane
To modify and re-use the waste polyurethane (PU),the intumescent flame retardant based on modified polyurethane (MPU) was prepared.Firstly,the phosphonic dichloride of polyurethane (PDP) was synthesized by using PU and phosphorus oxychloride (POCl3) as materials; Secondly,PDP reacted with melamine (MEL).The products were characterized by FTIR,SEMEDS and TGA.And the epoxy resin/MPU (EP/MPU) samples were prepared and tested by limiting oxygen index (LOI) method and vertical burning test (VBT) to evaluate the flame retarding performance.The results show that,the content of phosphorus in the PDP is about 19.6％ under the optimum reaction conditions as follows:using 1,4-dioxane as solvent,the concentrations of PU and POCl3 are about 20 g/L and 400 g/L respectively; the reaction temperature is 80℃ and the reaction time is 13 h.The LOI of EP/MPU (30％ MPU) is about 28％,and the flame retardant grade reached UL 94V-0.
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万方数据
维普
