苯基MDQ硅树脂的合成与性能

Synthesis and Properties of Phenyl-Substituted MDQ Silicon Resins

以正硅酸乙酯（TEOS）、二苯基二甲氧基硅烷（DMDPS）和六甲基二硅氧烷（MM）为原料,通过水解-缩合法制备苯基MDQ硅树脂.采用傅里叶红外光谱（FT-IR）和核磁共振氢谱（1H-NMR）对硅树脂的结构进行表征;利用热重分析仪（TG）、阿贝折射仪和凝胶渗透色谱仪（GPC）对产物热性能、折光率和相对分子质量及其分布进行测试.结果表明：随着DMDPS用量的增加,其折光率有所提高,相对分子质量略有降低,相对分子质量分布变宽,在氮气中的耐热性呈先增后减的趋势;空气中灼烧试验结果显示,在300℃以下,硅树脂的结构基本不变,导致其出现较大失质量的温度范围为300～500℃.

Phenyl-substituted MDQ silicon resins based on tetraethoxysilane （TEOS）, hexamethyldisiloxane（MM） and dimethoxydiphenylsilane （DMDPS） were synthesized by co- hydrolysis-condensation method. The structure of silicon resins was characterized by FT-IR and 1H-NMR. The thermal stability, refractive index, molecular weight and molecular weight distribution（MWD） of the synthesized resins were also investigated by thermal gravimetric a- nalysis （TGA） , Abbe refractometer and gel permeation chromatography（GPC）. The results in- dicated that the increase of DMDPS content could increase the refractive index of silicon res- ins, decrease the molecular weight slightly, broaden the MWD, and improve firstly and then affect negatively the thermal stability of silicon resins in nitrogen and air respectively. Further- more, the result of ignition test indicated that the silicon resins kept unchanged substantially in terms of the structure under a condition of temperature below 300 ℃ while showed an obvi- ous weight loss under the temperature range of 300 to 500 ℃.