Preparation And Properties Of Silicone Rubber Adhesive For Solar Cells

With the rapid development of science and technology in China and the continuous breakthroughs in the aerospace field,technological innovation in related fields has higher requirements for spacecraft.Industrial technicians will use efficient,convenient and other means to optimize China’s facilities and equipment in the aerospace field.The use of excellent adhesive and matching bonding technology is an indispensable part of the development of national defense and military industry in China.Adhesives are mainly used in space shuttles,space detectors,manned spacecraft and other aerospace technology fields.In the field of aerospace,as an important component of spacecraft,solar panels need to be able to cope with extremely severe and harsh space environment,such as resistance to high and low temperature alternation,high intensity radiation and so on.Silicone rubber adhesive has excellent properties such as chemical stability and high and low temperature resistance,so it is mainly used in high-tech fields.According to the actual demands in related fields,a two-component room temperature curing silicone rubber adhesive for spacecraft was prepared by usingα,ω-dihydroxy polydimethylsiloxane as base adhesive,and the heat resistance of the adhesive was further improved.the main conclusions are as follows:（1）First of all,the commonly used adhesive catalysts and coupling agents were selected for compounding.According to the actual requirements of surface drying time and curing,ethyl orthosilicate was used as cross-linking agent,dibutyltin dilaurate as catalyst,and KH550 and KH560 as coupling agent,respectively,in order to further explore the basic formula of adhesive.（2）By using the analysis method of orthogonal test,the effects of different factors in different coupling agent systems on the main properties of the adhesive were studied,and therefore the best formula of for KH550 and KH560 system was obtained respectively.By comparison,it is found that the adhesive with KH550 as coupling agent had more excellent low temperature resistance and adhesion properties,and its light transmittance could reach 97.9%.The lowest service temperature,that is,glass transition temperature（T_g）,reached-123.1℃,while the weight loss rate was less than 1.5%after heat treatment at 160^oC for 1 h,showing good thermal stability.（3）In order to further improve the heat resistance of silicone rubber adhesive with KH550 as coupling agent,polysilazane（PSZ）with different content（0.1～0.5 wt%）was added.The effects of polysilazane content on surface drying time,light transmittance and heat resistance of silicone rubber adhesive were studied.The results showed that with the increase of polysilazane content,the surface drying time of the adhesive increased significantly.Even though the light transmittance decreased gradually owing to the addition of polysilazane,it could still meet the essential requirements of more than 92%.At the same time,the addition of polysilazane had little effects on the Shore hardness and low temperature resistance of the adhesive.More importantly,thermogravimetric analysis showed that the T_5%and T_10%of the adhesive with 0.5 wt%polysilazane increased,indicating that the heat resistance of the adhesive was improved to some extent.According to the analysis of the reaction mechanism,it is believed that the introduction of polysilazane could react with the hydroxyl groups and residual water in the adhesive and therefore inhibit the degradation of the molecular chain.