摘要
以α,ω-二羟基聚二甲基硅氧烷(107硅橡胶)为基础聚合物,添加硅微粉、纳米二氧化铈、气相法二氧化硅、交联剂、硅烷偶联剂和催化剂,制得单组分室温硫化脱丙酮型有机硅密封胶。探讨了配方中交联剂用量、不同粒径硅微粉配比及用量、不同黏度107硅橡胶配比对有机硅密封胶性能的影响。结果表明:较佳的制备条件为交联剂用量为配方总质量的4%,平均粒径2μm和5μm硅微粉用量分别为75份和50份,纳米二氧化铈用量为4份,黏度20000 mPa·s和5000 mPa·s的107硅橡胶按质量比25∶75复配作基础聚合物。该条件下所得脱丙酮型有机硅密封胶的拉伸强度为4.52 MPa、拉断伸长率为172%、邵尔A硬度为52度,350℃老化30 min后的拉伸强度保持率为42.2%,拉断伸长率保持率为108.7%,硬度保持率为71.2%。该脱丙酮型有机硅密封胶适用于高温场合,如电磁炉、电熨斗、微波炉、烘箱等电器的粘接密封。
One-component room temperature vulcanization deacetonized silicone sealant has been prepared with α,ω -dihydroxy polydimethylsiloxane (107 silicone rubber ) as the basic polymer, nano ceria, fumed silica , crosslinking agent, silane coupling agent and catalyst. The effects of the amount of crosslinking agent, the proportion and amounts of different particle size, and the proportion of 107 silicone rubber with different viscosity on the performance of silicone sealants have been discussed. The results show that the optimal preparation conditions are: the cross-linking agent is 4% of the total mass, the amount is 75 phr and 50 phr respectively, with an average particle size of 2 μm and 5 μm, and the amount of nano-cerium oxide is 4 phr. 107 silicone rubber with a viscosity of 20 000 mPa · s and 5 000 mPa · s is compounded as base polymer at a mass ratio of 25∶ 75. The deacetonized silicone sealant has the tensile strength of 4.52 MPa, the elongation at break of 172%, Shore hardness of 52 A, and the tensile strength retention rate of 42.2 % after aging at 350 ℃ for 30 min, the retention rate of elongation at break of 108.7%, and the retention rate of hardness of 71.2%. The sealant can be used in the bonding and sealing occasions at high temperature, such as electric heating appliances, induction cookers, electric irons, microwave ovens, and ovens, etc.
作者
刘桂恒
李吉明
欧静
邓伟伟
LIU Gui-heng;LI Ji-ming;OU Jing;DENG Wei-wei(Guangzhou Mechanical Engineering Research Institute Co.Ltd.,Guangzhou 510700,Guangdong)
出处
《有机硅材料》
CAS
2021年第5期33-38,共6页
Silicone Material
关键词
脱丙酮
耐高温
有机硅密封胶
硅微粉
α
ω-二羟基聚二甲基硅氧烷
deacetonized
high temperature resistance
silicone sealant
microsilica
α
ω-dihydroxy polydimethylsiloxane