功能型LED CeO_2/苯基硅橡胶封装材料

采用表面覆盖改性技术,利用硬脂酸改性纳米CeO_2,将改性后的纳米m-CeO_2与苯基含氢硅树脂(PH)通过化学接枝制得m-CeO_2-PH接枝物,通过氢化硅烷化法,以接枝物为交联剂,在铂催化剂作用下制备了一种发光二极管(LED)封装用透明m-CeO_2/苯基硅橡胶材料。结果表明:经硬脂酸改性后m-CeO_2表面产生硬脂酸盐,增加了界面的相容性,提高了纳米CeO_2在聚合物中的分散。通过化学方法将m-CeO_2接枝到PH体系中,与苯基乙烯基硅树脂(PV)按化学计量比在催化剂作用下高温固化合成了一种功能型m-CeO_2/苯基硅橡胶材料。研究表明:当m-CeO_2质量分数为0.02%时,m-CeO_2/苯基硅橡胶材料的透光率仍可达到85%以上。同时,耐紫外老化性能和力学性能有明显提高。苯基硅橡胶材料中引入质量分数为0.02%的m-CeO_2,当分解温度到达600℃时,m-CeO_2/苯基硅橡胶材料的热失重比例比纯苯基硅橡胶减少了8%,m-CeO_2/苯基硅橡胶材料的放热量明显低于纯苯基硅橡胶,这对于封装有很大优越性。

CeO2/phenyl-silicone rubber composites for functional LED packaging materials

By surface covering modification technology, nano CeO₂ was modified by stearic acid, the modified nano m-CeO₂ and phenyl hydrogen containing silicone resin (PH) were chemically graftinged to prepare m-CeO₂-PH grafting. Atransparent m-CeO₂/phenyl-silicone rubber materials used for light-emitting diode (LED) packaging materials were prepared by the method of hydrogenation with grafting as cross-linking agent under the platinum catalyst.The results show that stearic acid salt produces on surface of m-CeO₂ after modified by stearic acid, which increases the compatibility of the interface and improves the dispersion of nano CeO₂ in polymer. m-CeO₂ was grafted in PH system by chemical method, then reacted with phenyl vinyl silicone resin (PV) with stoichiometric ratio under catalyst, and functional m-CeO₂/phenyl-silicone rubber materials were prepared through high temperature curing. Research shows that the light transmission rate of m-CeO₂/phenyl-silicone rubber materials reaches above 85% with 0.02% mass fraction of m-CeO₂, and ultraviolet aging properties and mechanical properties increase obviously. In addition when 0.02% mass fraction m-CeO₂ was introduced in phenyl-silicone rubber materials and decomposition temperature of CeO₂/silicone rubber composites is 600℃, the thermel gravimetric loss rate of m-CeO₂/phenyl-silicone rubber materials will cut down 8% than pure phenyl-silicone rubber, heat release of m-CeO₂/phenyl-silicone rubber materials is obviously lower than that of pure phenyl-silicone rubber which has superiority for LED packaging materials.