表面功能化SiO_2用于含油铸型尼龙的研究

Application of surface-functionalized SiO_2 in preparing oily monomer cast nylon

通过甲苯-2,4-二异氰酸酯(TDI)和十八烷醇(S)对纳米二氧化硅(SiO_2)进行表面功能化制得改性SiO_2(SiO_2-TDIS)。将含有SiO_2-TDIS的油料加入己内酰胺单体,通过阴离子开环聚合制得含SiO_2-TDIS/油铸型(OMC)尼龙复合材料,以提高复合材料的综合性能。通过傅里叶红外(FT-IR)、热重分析(TGA)、扫描电镜(SEM)和万能试验机等手段对复合材料的结构与性能进行表征。结果表明,SiO_2-TDIS的表面接枝率为17.3%;SiO_2-TDIS/OMC尼龙材料的热稳定性增强,晶型以α型为主,SiO_2-TDIS在油滴中的稳定性增强;当质量分数为0.125%的SiO_2-TDIS加入OMC复合材料时,拉伸强度、缺口冲击强度和弯曲强度分别提高17.5%、57.7%和32.4%。SiO_2-TDIS的加入使OMC尼龙拥有较好的力学性能和摩擦性能。

SiO2-TDIS is prepared through the surface functionalization of nano-SiO2 by toluene-2,4-diisocyanate（TDI） and stearyl alcohol（S）.SiO2-TDIS/oily monomer cast（OMC） nylon composites are gained through in situ anionic ring-opening polymerization by adding SiO2-TDIS-containing oil products into caprolactam monomer,which is aiming at improving the comprehensive properties of the composites.The thermal behavior,crystal behavior,mechanical properties and microstructure of SiO2-TDIS/OMC nylon composite are studied by means of FTIR,TGA,SEM,XRD and universal material testing system.The results show that the surface grafting rate of nano-SiO2 reaches 17.3 wt%,the thermal stability of SiO2-TDIS/OMC nylon material is enhanced,the crystalline form is dominated by α form and the stability of SiO2-TDIS in oil droplets rises.When the addition amount of SiO2-TDIS is 0.125 wt%,the tensile strength,notched impact strength and flexural strength of the composites increases by 17.5%,57.7% and 32.4%,respectively.The addition of SiO2-TDIS makes OMC nylon have better mechanical properties and friction properties.