Improved Self-Supporting and Ceramifiable Properties of Ceramifiable EPDM Composites by Adding Aramid Fiber.

Dong Zhao,Guodong Jiang,Yucai Shen,Tingwei Wang,Wei Liu

doi:10.3390/polym12071523

Dong Zhao, Guodong Jiang + Show 3 more

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https://doi.org/10.3390/polym12071523

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Journal: Polymers	Publication Date: Jul 9, 2020
Citations: 13	License type: CC BY 4.0

Affiliation: Nanjing Tech University

Abstract

Ceramifiable ethylene propylene diene monomer (EPDM) composites with fiber network structures were prepared by using aramid fiber (AF), ammonium polyphosphate (APP), and silicate glass frits (SGF). The effect of AF on the curing characteristic of the ceramifiable EPDM composites was studied. The morphology of AF in the composites system was observed by optical microscopy (OM) and scanning electron microscope (SEM). The effects of the observed AF network structures on the solvent resistance, mechanical properties, ablative resistance, self-supporting property, and ceramifiable properties of the composites were investigated. Results suggested that the existence of the AF network structure improved the vulcanization properties, solvent resistance, thermal stability, and ablative resistance of the EPDM composites. An excellent self-supporting property of the EPDM composites was obtained by combining the formation of the AF network and the formation of crystalline phases at higher temperature (above 600 °C). The thermal shrinkage performance of AF and the increased thermal stability of the EPDM composites improved the ceramifiable properties of the EPDM composites.

Highlights

Polymeric ablative materials are usually used for insulation and fire prevention in electric power and propulsion systems [1,2,3]
It was observed that ceramifiable ethylene propylene diene monomer (EPDM) has a different optimum cure time at different temperatures
Under the curing time of 900 s, EPDM was not in the plateau of vulcanizing curves at 160 and 170 ◦ C, while the state of vulcanized EPDM was in the plateau of vulcanizing curves at the temperature of 180 ◦ C

Summary

Introduction

Polymeric ablative materials are usually used for insulation and fire prevention in electric power and propulsion systems [1,2,3]. Ethylene-propylene-diene monomer (EPDM) represents one of the best matrices for polymeric ablative materials [4,5,6]; the thermal stability and electrical insulation of EPDM is comparable to or higher than that of other rubbers [7]. EPDM as a synthetic rubber is used in construction, electrical insulation, automobile manufacturing, and even propulsion systems of solid rocket motors [8,9,10,11]. EPDM composite has been often used in the thermal protection field because of its high char yield, which increases the ablation resistance and the thermal insulation performance [3,8,10,12]

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