用超临界氮气发泡技术制备复合纳米粒子填充聚氨酯弹性体发泡材料及其性能

Preparation and properties of composite nanoparticle-filled polyurethane elastomer foams using supercritical nitrogen gas foaming technology

在热塑性聚氨酯(TPU)基体中添加了由石墨烯、碳纳米纤维和碳纳米管复配而成的三元复合纳米填料(GFT),并采用超临界氮气发泡技术制备了TPU/纳米填料复合泡沫材料,研究了GFT含量对复合泡沫的泡孔密度、流变行为、热性能、微观形貌及导电性能的影响。结果表明,随着GFT含量的增加,TPU复合泡沫材料的储能模量和复数黏度有所增大、热稳定性有所提高。少量的GFT可以作为异相成核剂助力发泡,但其含量过多阻碍泡孔的增长,降低了发泡性能。GFT质量分数增加到2%以上时形成了填料网络,降低了TPU复合泡沫材料的结晶度,改善了其热稳定性和导热、导电性能。

A ternary composite nano-particle filler(GFT),comprising of graphene,carbon nanofibres and carbon nanotubes,was added to thermoplastic polyurethane(TPU)matrix.TPU/nanofiller composite foams were prepared by supercritical nitrogen gas foaming process.The effects of content of GFT on the cell density,rheological behaviour,thermal properties,microstructure morphology and conductivity of the composite foams were investigated.The results showed that with increase of GFT content,the storage modulus and complex viscosity of the TPU composite foam increased,and its thermal stability improved.A small amount of GFT composite nano-particle fillers could serve as heterogeneous nucleating agents to assist in foaming,but excessive GFT hindered the expansion of foam pores and reduce foaming efficiency.When the mass fraction of GFT increased to more than 2%,a filler network was formed,which reduced the crystallinity of the TPU composite foams and improved its thermal stability,thermal conductivity and electrical conductivity.