甲基环己基二甲氧基硅烷的合成

在一定压力下,以甲基二氯硅烷(DCM S)和环己烯为原料,在四甲基二乙烯基硅氧烷铂配合物催化剂(简称催化剂)的作用下,采用硅氢加成法制得中间体甲基环己基二氯硅烷(CMCS),再与甲醇反应,制得终产物甲基环己基二甲氧基硅烷(CHMM S);考察了原料配比、反应温度、反应压力、催化剂用量、促进剂种类、反应时间等条件对中间体CMCS收率的影响,采用傅里叶变换红外光谱和气相色谱-质谱法对CHMM S的结构进行了表征。实验结果表明,合成CMCS的最佳工艺条件为:反应压力0.7~0.8M Pa,n(DCM S)∶n(环己烯)=1.12,反应温度85~90℃,1m ol环己烯的催化剂用量1.0g,促进剂苯甲醛用量2.0g,反应时间5~6h;在此条件下,CMCS的收率可达89.6%,CMCS的质量分数可达99.61%。CHMM S的合成条件为:第一阶段反应在室温下进行,n(甲醇)∶n(CMCS)=1.29;第二阶段反应在低于39℃下进行,n(甲醇)∶n(CMCS)=4.83。通过常压蒸馏及减压精馏,得无色透明液体产品CHMM S的收率为78.3%,CHMM S的质量分数为99.75%。

Synthesis of Cyclohexylmethyldimethoxysilane

Cyclohexylmethyl dimethoxysilane(CHMMS)was used as external electron donor in polypropylene catalyst system.Its preparation was studied by hydrosilylation of dichloromethylsilane(DCMS)with cyclohexene on platinum complex of 1,3-divinyl-1,1,3,3-tetramethyl disiloxane catalyst to produce an intermediate,namely cyclohexylmethyl dichlorosilane(CMCS).CMCS then further reacted with methanol to synthesize the end product CHMMS.Structure of CHMMS was characterized by means of FTIR and GC-MS.Effects of n(DCMS) ∶n(cyclohexene),reaction temperature,pressure,time,catalyst dosage and promoter type on CMCS yield were investigated.Optimal reaction conditions for preparation of CMCS were:n(DCMS) ∶n(cyclohexene)=1.12,reaction temperature 85-90℃,pressure 0.7-0.8MPa,time 5-6h,catalyst dosage 1.0g per mole cyclohexene and benzaldehyde dosage 2.0g.Under above optimal conditions,yield and mass fraction of CMCS could reach 89.6% and 99.61%,respectively.Optimal reaction conditions for preparation of CHMMS were:in first stage of reaction,n(methanol) ∶n(CMCS)=1.29 and reaction temperature:ambient;in second stage of reaction,n(methanol) ∶n(CMCS)=4.83,reaction temperature lower than 39℃.Under above optimal conditions,yield and mass fraction of CHMMS could be up to 78.3% and 99.75%,respectively.