聚氨酯/甲基二苯基氧化膦的冷结晶及阻燃性能研究

Cold crystallization and flame retardancy of polyurethane/methyldiphenylphosphine compounds

将新型阻燃剂甲基二苯基氧化膦(DPMP)与聚氨酯(PU)复合,并采用片状黏土为协效剂,通过极限氧指数(LOI)测试、垂直燃烧测试(UL 94)和微型量热分析(MCC)研究了DPMP和黏土对复合材料阻燃性能的影响,并采用示差扫描量热仪(DSC)、热失重分析仪(TG)分析了复合材料的结晶性能及热降解行为。结果表明,DPMP能促进PU冷结晶,从而提高其模量和力学性能。当PU复合材料中DPMP含量(质量分数,下同)为10%时,PU的LOI值从23%增加到28.3%。PU/10%DPMP的模量、断裂伸长率和拉伸强度分别为1.37 MPa、1042%和13.84 MPa,纯PU的相应分别为1.17 MPa、811%和11.32 MPa。当体系进一步加入黏土,1%的黏土即可使PU/DPMP的滴落现象消失,UL 94达到V-0级。

A novel flame retardant,methyl diphenyl phosphine oxide(DPMP),was compounded with polyurethane(PU)to obtain flame-retardant PU composites by using flake clay as a synergist.The effects of DPMP and clay on the flame retardancy of the composites were investigated through ultimate oxygen index(LOI),vertical combustion(UL 94),and micro calorimetry.The crystallization properties and thermal degradation behaviors of the composites were analyzed by using differential scanning calorimetry and thermogravimetric analyzer.The results indicated that DPMP could promote the cold crystallization of PU,thus improving its modulus and mechanical properties.The addition of 10 wt%DPMP increased the LOI value of PU from 23 to 28.3 vol%,and the resultant composite obtained a modulus,elongation at break,and tensile strength of 1.37 MPa,1042%and 13.84 MPa,respectively,while the corresponding values for pure PU were 1.17 MPa,811%and 11.32 MPa,respectively.With a further addition of 1 wt%clay,the dripping phenomenon of the composites could be eliminated,enabling the composites to achieve a UL 94 V-0 classification in the vertical burning test.