Ablation and erosion characteristics of EPDM composites under SRM operating conditions

The current research discusses the properties of an elastomeric heat-shielding material, based on nano-silica (NS) filled ethylene propylene diene monomer (EPDM) rubber/Kevlar fiber (KF) hybrid composites. The developed elastomeric insulating material consists of an aromatic polyamide fiber (KF) and silica nanoparticles. An in-depth analysis of mechanical properties, density, coefficient of thermal expansion, thermal conductivity, thermogravimetric analysis, and heat release rate of the insulating materials-was performed. TEM micrograph represents an excellent distribution of nanoparticles in the EPDM matrix. The improvement in the mechanical and the flame retardancy of the NS filled EPDM/KF hybrid composite insulations is based on the fiber/ matrix adhesion. Maleic anhydride grafting confers polarity to the nonpolar rubber matrix. The char residues of the insulations inspected by scanning electron microscopy and energy dispersive spectroscopy are depicting a rigid and rough surface by the optimal composites, which can aid in better insulation. The optimal formulation of the hybrid composites exhibited a 220% enhancement in char residue with improved thermal stability and mechanical properties.

Section: Morphological Analysis Of the Char Residuementioning

confidence: 99%

Thermal insulation behaviour of Ethylene propylene diene monomer rubber/kevlar fiber based hybrid composites containing Nanosilica for solid rocket motor insulation

George

Mohanty

Biswal

et al. 2020

“…In general, aramid fiber is the most widely used material 14 . Li et al 15 has studied the effect on the combination of silica and aramid fiber. The results implied that both non‐silica and non‐fiber EPDM formulations exhibited poor ablation resistance.…”

Section: Introductionmentioning

confidence: 99%

Effect of hybrid cross‐linked polyphosphazene microspheres on ablative and mechanical properties of ethylene propylene diene monomer

Chen

He²,

Liu

et al. 2021

Polymeric ablative materials (PAMs) are widely used in spacecraft currently for thermal insulation. However, it is challenging to find a single filler that can improve both ablative and mechanical properties of PAMs. In this study, a new type of hybrid cross‐linked polyphosphazene microspheres (PHC) is added to ethylene propylene diene monomer (EPDM) composites as a filler for the first time and its influence on the ablation, mechanical, and thermal properties of EPDM is investigated. The results show that the addition of 3 phr PHC increases the ablation performance by about 10% and enhances the mechanical properties by 20% approximately. In addition, the ablation mechanism is studied in accordance with SEM, FTIR, and Raman spectroscopy. On the one hand, PHC has the effect of catalyzing carbonization, thus increasing the rate of residual carbon; on the other hand, PHC changes the morphology of the char layer, forming a cross‐linked structure containing P─O─Si bonds on the surface. The findings regarding catalyzing carbonization and the special char layer structure could guide the design of ablative materials.

“…Compared with traditional flexible substrates such as nitrile rubber 8 and EPDM rubber, [9][10][11][12] silicone rubber has a high char retention rate and it can form a high-temperature-resistant ceramic layer, thereby attracting sufficient research attention. The study on ablative resistant silicone rubber mainly focuses on two aspects, namely the modification of the silicone rubber matrix [13][14][15][16][17] and the interaction of silicone rubber with various fillers.…”

Section: Introductionmentioning

confidence: 99%

Ablation properties of zinc borate and aluminum hypophosphite filled silicone rubber composites

Zhang

Yan

Wang

et al. 2021

The ablative properties of epoxy modified silicone rubber composites filled with zinc borate (ZB) and aluminum hypophosphite (AHP) were studied. The decomposition of the added fillers and covering connection of residual on the substrate contribute to the improvement of heat insulation. The ablation test shows that the formation of a dense char layer with certain strength is key to improving the ablative properties. The optimal ablative performance is achieved when the concentration of ZB and AHP is 10 and 5 phr, respectively. Under such circumstances, the linear ablation rate is as low as 0.032 mm/s, which is about 61% lower than the pure silicone rubber. Furthermore, the structure and composition of the formed char layer were analyzed using X‐ray diffraction analysis, scanning electron microscopy, and Fourier transform infrared spectroscopy.