固体火箭发动机外防热涂层用改性硅烷粘接剂性能研究

Study on performance of modified silicone adhesive for SRM external thermal protection coating

固体火箭发动机外防热涂层体系包括钢壳体/底漆/粘接剂/涂层/面漆,其中粘接剂用于底漆和涂层间的粘接。目前常用粘接剂为多种硅烷混合物,由于受环境温湿度的影响大,导致发动机外防热涂层在热考核中易发生界面脱粘。为了提高界面粘接的可靠性,以发动机钢壳体基材和硅橡胶基外防热涂层为研究对象,开展了硅烷粘接剂的研制工作。以多烷基硅烷和氨基化合物为原料,分别制备了氨基改性硅烷DTJ-1和酰胺基改性硅烷DTJ-2,采用红外光谱(FT-IR)、核磁共振(NMR)、X射线能谱(EDS)以及接触角(CA)等手段进行了表征分析,并开展了粘接性能和热考核试验。结果表明,DTJ-2的常温、高温粘接强度分别为1.221 MPa和0.48 MPa,均优于DTJ-X的1.069 MPa和0.34 MPa,且通过了石英灯加热考核和动态电弧风洞试验。

External thermal protection coating system of SRM includes case/primer/adhesive/coating/top-coat,and the adhe-sive is applied to bond primer and coating.Common adhesives are a mix of several kinds of silane,due to large effects by ambienttemperature and relative humidity,it is easy to occur motor external thermal protection coating debonding during the process of ther-mal test.With SRM case and silicone rubber coating as the object of the research, the research work of silicone adhesives was car-ried out to enhance reliable interface bonding. Respectively,Amino-modified silane called DTJ-1 and acylamino-modified silanecalled DTJ-2 were synthesized from multi-alkyl silane and amide.Synthesized adhesives were characterized by Fourier transform in-frared(FT-IR),nuclear magnetic resonance(NMR),energy dispersive spectrum analysis(EDS) and contact angle(CA).Then,bonding properties and thermal test were carried out.The results show that normal-temp and high-temp shear strengths of DTJ-2 canreach 1.221 MPa and 0.48 MPa,which are superior to 1.069 MPa and 0.34 MPa of DTJ-X,and DTJ-2 has passed static quartz lampradiation test and arc-heated wind tunnel test.