High efficiency thermal insulation material based on boron hybrid silicone rubber and hollow microspheres

In this study, a new type of thermal insulation protective material with good thermodynamic properties was successfully prepared. Using boron hybrid silicone rubber (B-SR) as matrix and hollow ceramic microsphere (HCM), hollow silica microsphere (HSM) and hydroxy silicone oil foaming agents (OH-3#) as thermal insulation phase, a single thermal insulation phase (HCM/B-SR, HSM/B-SR, OH-3#/B-SR) was prepared, and the influence of single thermal insulation function on the performance of thermal insulation material was studied. Based on the influence of single thermal insulation function phase on the performance of thermal insulation material, orthogonal experiment was designed to study the influence of composite thermal insulation function phase on the performance of thermal insulation material. The influence of single and composite thermal insulation function phase on thermal performance and mechanical properties of insulation materials were studied by scanning electron microscopy, thermogravimetric analysis plate thermal conductivity meter and universal testing machine, respectively. Through the orthogonal design experiment and further optimization, the final formula of boron hybrid silicone rubber-based thermal insulation protection material was obtained. When B-SR: HCM: HGM: OH-3# = 100: 15: 25: 18, the comprehensive performance of multiphase composite insulation materials was the best. The results showed that the thermal conductivity of the thermal insulation material under the formula is 0.064 W/(m K), T₁₀ is 549.9 °C, T_max is 621.3 °C, R₁₀₀₀ is 77.5%, tensile strength is 2.43 MPa, elongation at break is 73.6%, compression modulus is 11.7 MPa, hardness is 43°. The good synergistic effect of different thermal insulation function phases ensured the technical requirements of warhead thermal insulation protection materials for low thermal conductivity, high heat resistance and structural strength to the greatest extent. This study is of great significance for preparing highly efficient thermal insulation materials through the organic combination of HM filling and chemical foaming.