纳米碳酸钙复配对有机硅密封胶性能的影响

Effect of Nano-Calcium Carbonate Composite on the Properties of Silicone Sealant

采用α,ω-二羟基聚二甲基硅氧烷、二甲基硅油和纳米碳酸钙制得基料,再添加交联剂、催化剂等制得有机硅密封胶,考察了5种纳米碳酸钙和4种复配纳米碳酸钙对有机硅密封胶挤出性和拉伸性能的影响。结果表明,采用单一品种纳米碳酸钙制备有机硅密封胶时,随着纳米碳酸钙比表面积或吸油值的增大,有机硅密封胶浆料的稠度值变小,挤出性下降,硫化胶的拉伸强度、拉断伸长率提高。通过优选不同比表面积的纳米碳酸钙粉体进行复配,可制得综合性能优良的有机硅密封胶。

Calcium carbonate nanoparticles are important reinforcing fillers for silicone adhesives.α,ω-dihydroxypolydimethylsiloxane,dimethyl silicone oil,and nano calcium carbonate(CaCO 3),were used as base materials,followed by the addition of crosslinking agents,catalysts,to prepare silicone sealant.The effects of 5 types of nano CaCO 3 and 4 types of composite nano CaCO 3 on the extrusion and tensile properties of the silicone sealant were investigated.The results showed that when using one single nano CaCO 3 to prepare silicone sealant,with the increase of the specific surface areas or oil absorption value of nano CaCO 3,the consistency value and extrudability of the silicone sealing paste decreased;the tensile strength and elongation at break of the rubbers improved.By selecting nano CaCO 3 powders with different specific surface areas,the silicone sealant could be prepared with excellent comprehensive performance.