微胶囊化硅藻土吸附改性矿用聚氨酯泡沫

Microcapsule diatomite adsorption modified mineral polyurethane foam

针对目前矿用聚氨酯泡沫(RPUF)易燃以及阻燃剂磷酸三(2-氯丙基)酯(TCPP)、甲基膦酸二甲酯(DMMP)的应用易引起材料“坍塌”和力学性能下降等问题,采用硅藻土吸附和仿贻贝材料表面包覆的方法对传统阻燃剂进行了改性,设计并制备了环境友好的微胶囊化硅藻土吸附阻燃剂(MDFR)。利用万能试验机研究了MDFR对RPUF力学性能的影响;采用极限氧指数、垂直燃烧、锥形量热的测试手段,研究MDFR对RPUF阻燃性能的影响;利用扫描电子显微镜和热重分析等表征,研究了MDFR对RPUF微观形貌以及热稳定性的影响,并探讨了阻燃机理。结果表明,阻燃剂MDFR的加入,相比于传统阻燃剂DMMP和TCPP,RPUF的力学性能得到能明显改善,微观泡孔结构完整,并且其热解活化能升高,热稳定性增加;同时,MDFR在抑制RPUF燃烧时的烟气释放和CO释放方面效果明显,降低了有毒有害气体的释放。机理分析显示,MDFR的加入使阻燃RPUF燃烧后炭层厚度和致密性增加,有效阻止了材料燃烧过程中的热交换和可燃性气体、有毒气体的释放,使之在使用过程中更加安全。对比两种改性阻燃剂MDFR-1和MDFR-2,以TCPP为原料改性的MDFR-2阻燃剂效果更优。

Aiming at the flammability of mining polyurethane foam(RPUF),the material collapse and the decline of mechanical properties because of the application of flame retardants tris(2-chloropropyl)phosphate(TCPP)and dimethyl methylphosphonate(DMMP)Traditional flame retardants were modified by diatomite adsorption and mussel-like material surface coating,and environmentally friendly microencapsulated diatomite adsorption flame retardant(MDFR)was designed and prepared.The influence of MDFR on the mechanics,the flame retardancy,the microscopic morphology and thermal stability of RPUF was studied by the universal test machine,the methods of limiting oxygen index,vertical combustion,cone calorimetry,scanning electron microscopy and thermogravimetric analysis.The results show that the mechanical properties of RPUF are significantly improved compared with traditional flame retardant DMMP and TCPP,the microcosmic vesicle structure is intact,the pyrolysis activation energy is elevated,and the thermal stability is increased;at the same time,the effect of MDFR in inhibiting the release of smoke and CO during the combustion of RPUF is obvious,and it reduces the release of toxic and hazardous gases.Mechanism analysis shows that the addition of MDFR increases the thickness and densification of the charcoal layer after combustion of flame retardant RPUF,effectively preventing the heat exchange and the release of combustible and toxic gases during the combustion process of the material,making it safer to use.Comparing the two modified flame retardants MDFR-1 and MDFR-2,the modified MDFR-2 flame retardant with TCPP as raw material is more effective.