埃洛石-二氧化锆改性聚磷腈橡胶基复合材料高温烧蚀行为和原位陶瓷化反应OA北大核心CSTPCD

Poly(diaryloxyphosphazene)rubber is a potential matrix for the preparation of thermal insulation materials due to its excellent flame retardant,thermal stability and high carbon residue rate.In order to improve the ablative resistance of poly(diarylo-xyphosphazene)rubber composites,HAL-ZrO2 poly(diaryloxyphosphazene)rubber matrix composites were prepared by using Hal-loysite(HAL)and ZrO2 as ceramic fillers.The effects of the mixed ceramicizable system on the mechanical properties,thermal sta-bility and ablative properties of the composites were studied.The results show that HAL and ZrO2 have no effect on the tensile me-chanical properties and thermal stability of PDPP composites.The tensile strength of PDPP composites with 5 phr HAL and 15 phr ZrO2 mixed ceramic system is 4.57 MPa and the elongation at break is 104.4%,and the linear ablation rate of the compos-ites after oxyacetylyne ablation is 0.060 mm/s,which is 43.4%and 33.2%higher than that of HAL and ZrO2 alone.XRD and XPS show that the residual carbon after pyrolysis of the rubber matrix has in situ ceramic reaction with SiO2 and ZrO2 to form SiC and ZrC,respectively.During the ablation process,the low melting point ceramic filler bonded the carbon layer formed by the pyrolysis of the matrix with the high melting point ceramics,making it become a dense and strong ceramic-like layer containing the ceramic-glass-pyrolysis carbon composite structure,which plays a positive role in improving the ablation resistance of the composites.