低密度抗压防热涂层制备与性能

目的以硅橡胶为树脂基体,通过添加补强填料、空心微球、助剂、分散溶剂等,制备低密度抗压防热涂层。方法首先从低密度抗压涂层的特点分析了低密度抗压涂层的设计思路,然后从补强硅橡胶、填料及涂料的储存稳定性三方面对涂层配方进行了分析,最后对涂层物理、粘接、固化、抗压性能进行了分析。结果低密度抗压放热涂层需具备韧性好、强度高、孔隙率低等特点。通过补强填料比例优化和空心微球复配,兼顾了涂层低密度和高抗压的特点。通过防沉助剂的添加,大幅改善了低密度涂料的分层和结块现象。所制备低密度抗压防热涂层室温放置6 d后固化完全,涂层密度为0.457 g/cm~3,拉伸强度为1.51 MPa,涂层与基材具有良好的粘接性,在2 MPa的压力下放置20 d,厚度减少12%~13%。结论制备得到的低密度抗压涂层密度低于0.5 g/cm~3,且具有优良的抗压性能,未来可用于气动热防护。

Preparation and Performance of Low Density and Compression Resistance Thermal Protection Coating

The work aims to prepare low density and compression resistance thermal protection coating by taking silicone rubber as resin matric and adding reinforce fillers, hollow microspheres, agents, dispersion solvent, etc. The design idea was analyzed based on features of low density and compression resistance coating; then the ingredients of coating were studied according to storage stability of reinforced silicone rubber, filler and coating; finally the physical, adhesive, curing and compression properties were analyzed. The low density and compression resistance thermal protection coating had good flexibility, high strength and low porosity. Low density and high compression resistance were both obtained by optimizing the reinforced filler proportion and compounding the hollow microspheres. The layering and agglomeration phenomenon of the low density coating was improved dramatically by adding anti-settling agents. The prepared low density and compression resistance thermal protection coating was completely curried after 6 days at room temperature. The density of coating was 0.457 g/cm3, the tensible strength was 1.51 MPa and the coating and the base materials were bonded well. The coating thickness decreased by 12%~13% after 20 days at 2 MPa. The prepared low density and compression resistance coating can be used to protect aerodynamic heat in future due to the density below 0.5 g/cm3, and the good compression resistance.