A comparison of ablative resistance properties of liquid silicone rubber composites filled with different fibers

Abstract

Flexible ablative materials play a key role in thermal protection systems to protect space vehicles during hypersonic flight missions. In this work, epoxy resin modified liquid silicone rubber was adopted as elastomeric matrix. Two inorganic fibers (carbon fibers (CF) and quartz fibers (QF)) and two organic fibers (aramid fibers (AF) and poly (p‐phenylene benzobisoxazole) fibers (PBO)) were chosen as functional fillers. The ablation resistance and thermal insulation properties were evaluated using oxyacetylene torch test. Microstructure and phase composition of the char layer was fully characterized to investigate the ablation mechanism. SEM observations revealed that the fibers are well dispersed and integrated in the matrix. TGA analysis indicated that the inorganic fibers possess significantly higher thermal stability than organic fibers. In addition, a molten silica film can be formed on the material surface, which can exert a better thermal protection effect on the matrix. Furthermore, the ablation test shows that the linear ablation rate decreases first and then increases with an increase of fiber content. This work provides basic data to guide optimal selection of fibrous ablatives to enhance ablation performance.

Ablation Response Behavior under Different Heat Flux Environments for Liquid Silicone Rubber Composites

“…Liquid silicone rubber-based ablative materials exhibit great development prospects in thermal protection fields due to their good properties and excellent designability. 19 Depending on the hyperthermal environment in which these materials must work, many types of formulations have been developed. Up to now, a wide range of fibers, 20,21 powdered fillers, 22−26 and nanosized reinforcements 27−29 resistance of these materials.…”

“…To date, the most widely used elastomeric matrices include nitrile butadiene rubber (NBR), ethylene propylene diene monomer rubber (EPDM), − and silicone rubber (SR). , Among them, SR, as an inorganic (semi-organic) material, has received more and more attention due to its excellent oxidation resistance and heat resistance, which is attributed to its special structure with Si–O–Si. Liquid silicone rubber-based ablative materials exhibit great development prospects in thermal protection fields due to their good properties and excellent designability …”

Electrical insulation properties of silicone rubber under accelerated corona and thermal aging

“…For FTIR identification, the wave numbers and their corresponding functional groups related to the studied material are deduced from references [25][26][27] and shown in Table 1. Relative intensities of each peak in Figure 8, normalized to the most intense peak (790 cm −1 Si (CH 3 ) 2 bond) at 1200 h are also given in Table 1.…”

Fatigue failure behavior of aramid fiber reinforced styrene butadiene rubber composite with different fiber coatings

“…As it is composed of finely crystalline regular rigid straight chains, it possesses excellent properties such as high modulus, high strength and fatigue resistance 20–22 . A small amount of AF has been used to reinforce SBR material, resulting in significantly improving the strength and fatigue performance 23–25 . Yin et al 26 proposed that AF with a well‐bonded flexible interface layer has an obvious attraction to fatigue cracks and can effectively slow down their growth.…”