Improved Mechanical and Ablative Properties of PDMS Coatings Incorporating Epoxy as a Suspended Chain

Flexible thermal protection materials with excellent mechanical and ablative properties were one of the key components in promoting the development of a new generation of aircraft. In the present work, a robust, strongly adhesive, and ablation-resistant PDMS coating was prepared through the covalent connection between PDMS and vinyl-functionalized epoxy resin (EAP) by hydrosilylation. The EAP synthesized by molecular design was uniformly dispersed in the PDMS matrix as an island phase-separation structure. The tensile strength, elongation at break, and shear strength of EAP-modified PDMS (EAP@PDMS) were significantly increased by 575%, 155%, and 183%, respectively, when compared with pure PDMS. Besides, the linear ablation rate (LAR) of EAP@PDMS was greatly declined, which was 80.1% lower than that of pure PDMS, exhibiting excellent ablation resistance. This work opened an avenue toward developing flexible thermal protection coatings with excellent mechanical and ablative properties for aerospace applications.