碳纤维/聚硅氧硼烷阻燃改性环氧复合材料的制备及性能

Preparation and Properties of Carbon Fiber/Poly(siloxane-borane)Flame Retardant Modified Epoxy Composite

以苯硼酸和含磷硅氧烷为主要原料,设计合成了一种以Si-O-B为主链,侧链含苯环和磷杂菲基团的聚硅氧硼烷(PTDOB),在此基础上,以PTDOB为阻燃剂,碳纤维(CF)为增强材料,通过手糊结合模压成型的工艺制备了一种碳纤维/聚硅氧硼烷阻燃改性环氧复合材料(CF/PTDOB-EP)。采用极限氧指数、垂直燃烧、冲击强度和弯曲强度探究了CF/PTDOB-EP的阻燃和力学性能。结果表明,PTDOB的引入有效改善了复合材料的阻燃性能,CF/PTDOB-EP的极限氧指数提高到36.7%,并且通过了UL-94测试的V-1等级,说明PTDOB结构的磷杂菲和Si,B等元素充分发挥了阻燃作用。同时,CF/PTDOB-EP的冲击强度和弯曲强度分别达到120.5kJ/m^(2)和524.3MPa,提高了66.7%和37.4%,这是因为PTDOB结构中刚性的苯环和柔性的Si-O-B结构协同作用,赋予了CF/PTDOB-EP良好的力学性能,从而拓宽了碳纤维增强环氧复合材料的应用范围。

Poly(siloxane-borane)(PTDOB)with Si-O-B as main chain and benzene ring and phosphaphenanthrene groups in side chain was designed and synthesized through the reaction between phenylboric acid and phosphorus-containing siloxane.Then,carbon fiber/poly(siloxane-borane)flame retardant modified epoxy composites(CF/PTDOB-EP)were prepared with PTDOB as flame retardant and carbon fiber(CF)as reinforced material by hand lay-up combined through hot press molding process.The flame retardancy and mechanical properties of CF/PTDOB-EP were investigated by limiting oxygen index,vertical combustion,impact strength and bending strength.The results show that the introduction of PTDOB effectively improves the flame retardancy of CF/PTDOB-EP with a limit oxygen index value of 36.7% and V-1 grade of UL-94 test,indicating that the phosphaphenanthrene and Si,B elements of PTDOB have excellent flame retardant effect.Meanwhile,the impact strength and bending strength of CF/PTDOB-EP reach 120.5 kJ/m^(2) and 524.3 MPa,increased by 66.7% and 37.4% respectively.This attributes to the synergistic effect of the rigid benzene rings and flexible Si-O-B structure in PTDOB endowed CF/PTDOB-EP with good mechanical properties,thus broadening the application ranges of carbon fiber reinforced epoxy composites.