以酸性白土为催化剂,八甲基环四硅氧烷、六甲基二硅氧烷为原料制备了低黏度?二甲基硅油,研究了温度对酸性白土催化活性的影响,酸性白土用量对转化率的影响以及六甲基二硅氧烷用量对产物黏度的影响,并对产物性能进行了表征.结果表明:酸性白土催化活性受温度影响较大,80℃时反应达到平衡的时间仅为70℃时的1/4,其催化活性好、用量少,且制得的二甲基硅油热稳定性更佳,透明性更好.但酸性白土细度小,难过滤,只适合于制备低黏度二甲基硅油.%Dimethyl silicone oil with low viscosity was preparared by octamethylcyclotetrasiloxane and hexamethyldisiloxane as the base materials, and acid activated bentonite as the catalyst.Effects of polymerization temperature on the catalytic activity of acid activated bentonite were discussed, and the content of acid activated bentonite on the conversion were discussed.Effect of the content of MM on the viscosity of the prepared products was also characterized as well.Results show that the catalytic activity of acid activated bentonite is affected by temperature, the equilibrium time of the reaction at 80℃ is only 1/4 of 70℃, the acid activated bentonite exhibites good catalytic activity, less addition amount, and the prepared dimethyl silicone oil has better thermal stability and transparency.The disadvantage of the acid activated bentonite is the small fineness makes it hard to filter, only suitable for preparation of low viscosity methyl silicone oil.
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