脱酮肟型低模量硅酮密封胶的研制

Development of deketoxime type low modulus silicone sealant

试验选用α,ω-羟基聚二甲基硅氧烷为107基胶,以纳米碳酸钙和重质碳酸钙复配补强,通过加入一定量增塑剂、扩链剂与催化剂等功能类原料,研制了一款拉伸模量低、弹性好的脱酮肟密封胶,分别考察了107基胶黏度、填料类型、增塑剂与扩链剂用量对密封胶拉伸粘接性能的影响。试验结果发现,向100 g黏度为80 000 m Pa·s的基胶中,投入50 g二甲基硅油、80~120 g(按m(纳米碳酸钙)∶m(重质碳酸钙)=3∶1复配而成)补强填料、0.6 g扩链剂和0.8 g催化剂制成的硅酮密封胶,各项综合性能基本达到国标GB/T 22083-2008《建筑密封胶分级和要求》中低模量性能的要求。

In the test,α,ω-hydroxypolydimethylsiloxane was used as the 107 base glue,reinforced with nano-calci⁃um carbonate and heavy calcium carbonate,and a certain amount of functional raw materials such as plasticizers,chain extenders and catalysts were added to develope a deketoxime sealant with low tensile modulus and good elas⁃ticity.The effects of 107-base adhesive viscosity,filler type,plasticizer and chain extender dosage on the tensile ad⁃hesion performance of sealant were investigated.The test results found that,the comprehensive properties of the sili⁃cone sealant,which was made of 100 g of base rubber with a viscosity of 80000 mPa·s,50 g of dimethicone oil,80~120 g reinforcing filler(according to m(nano calcium carbonate)∶m(heavy calcium carbonate)=3∶1 compound),0.6 g chain extender and 0.8 g catalyst,basically met the requirements of low modulus performance in the national standard GB/T 22083-2008“Classification and Requirements for Building Sealants”.