改性纳米二氧化硅在环氧树脂膨胀阻燃体系中的协效作用研究

Synergist effect of the graft modifying nano-silica on intumescent flame retardant epoxy resin system

以膨胀阻燃剂(IFR)为主要阻燃剂,以纳米二氧化硅(Nano-SiO_(2))及KH570改性纳米二氧化硅(SiO_(2)-g-KH570)为协效剂制备阻燃环氧树脂(EP)材料,对比研究了2种EP/IFR/SiO_(2)及EP/IFR/SiO_(2)-g-KH570体系材料的阻燃性能、力学性能、热量释放、烟气释放、热降解行为及炭层表面形貌。结果表明,当阻燃剂的总添加量为环氧树脂基体质量分数的30%(SiO_(2)为IFR质量的10%)时,SiO_(2)与IFR具有阻燃协同效应,在同样的添加比例下,改性的SiO_(2)会增强这种协同作用。EP/IFR/SiO_(2)-g-KH570体系与EP/IFR/SiO_(2)体系相比,两者氧指数(LOI)分别为30.2%和28.6%,UL-94测试分别通过V-0和V-1级;EP/IFR/SiO_(2)-g-KH570的力学性能较EP/IFR/SiO_(2)也有所提高,弯曲强度和抗冲击强度分别提高了10.2MPa和0.6KJ·m^(-2);锥形量热及热分析结果表明,EP/IFR/SiO_(2)-g-KH570体系在热释放、CO和CO_(2)释放指标上数值明显降低,热稳定性增加;残炭的电镜形貌分析表明,EP/IFR/SiO_(2)-g-KH570体系能形成更加致密和连续的炭层,能起到很好的物理屏障作用,显示出较好的阻燃效果。

The Flame-retardant epoxy resin(EP)composites were prepared with intumescent flame retardant(IFR)as the main flame retardant,nano-SiO_(2) and nano-SiO_(2)-g-KH570(SiO_(2) modified by KH570)as synergistic agent.The flame retardancy performance,mechanical properties,heat release,smoke emission,the morphological of char residue and thermal decomposition of EP/IFR/SiO_(2) and EP/IFR/SiO_(2)-g-KH570 systems were investigated comparatively.The results indicated that SiO_(2) and IFR have good coordinated effect when 30%the total loading amount of IFR which is along with 10%SiO_(2) corresponding to the IFR was added to epoxy resin matrix.Moreover,on the basis of same mass ratio,The modified SiO_(2) can enhancen the coordinated effect compared to SiO_(2).The LOI value of EP/IFR/SiO_(2)-g-KH570 and EP/IFR/SiO_(2) system was 30.2%and 28.6%,which achieved the verticla burning(UL-94)V-0 and V-1,respectively;The EP/IFR/SiO_(2)-g-KH570 system had better mechanical properties compared with EP/IFR/SiO_(2),The flexural strength and impact strength are increased by 10.2MPa and 0.6KJ·m^(-2),respectively.The EP/IFR/SiO_(2)-g-KH570 in contrast with EP/IFR/SiO_(2),It showed the release of heat,smoke gas much decreased,the thermal stability increased,and CO and CO_(2) gas release was lower;The morphological analysis of char residue of EP/IFR/SiO_(2)-g-KH570 system showed that a more compact and continuous charring layer can be formed,which played a good physical barrier role,and showed a better flame retardant effect.