二甲基二氯硅烷水解物裂解工艺探讨

Study on Cracking Process of Dimethyldichlorosilane Hydrolysate

以二甲基二氯硅烷水解物为原料,正十八醇为溶剂,在KOH催化作用下裂解得到二甲基环硅氧烷混合物(DMC)。研究了催化剂用量、溶剂油用量、反应温度、体系真空度对DMC产量和八甲基环四硅氧烷(D4)含量的影响。结果表明,随着催化剂用量的增加,DMC产量逐渐升高并趋于稳定,D4含量基本保持稳定;随着溶剂油用量增加,DMC产量降低,D4含量升高;随着反应温度的升高,DMC产量升高,D4含量下降;随着裂解釜压力升高,DMC产量急剧降低,D4含量逐渐升高。较佳的工艺条件为:催化剂用量0.33%,溶剂油用量为裂解釜容积20%,反应温度155℃,裂解釜压力6 k Pa(A)。

Dimethylcyclosiloxane(DMC)mixture was obtained from dimethyldichlorosilane hydrolysate with n-octadecyl as solvent and KOH as catalyst.The effects of catalyst content,solvent oil content,temperature and vacuum degree on DMC yield and D4 content were studied.Results showed that with the increase of catalyst,the output of DMC increased and tended to be stable,and the contents of D4 remained stable;with the increase of solvent oil,the output of DMC decreased and the contents of D4 increased;with the increase of temperature,the output of DMC increased and the content of D4 decreased;with the increase of cracking reactor pressure,the output of DMC decreased sharply and the content of D4 increased gradually.The optimum process conditions are as follows:catalyst of 3.33%,20%solvent oil of the cracking kettle volume,under temperature of 155℃and cracking kettle pressure of 6 kPa(A).