에틸렌 공중합체/테트라졸화니트릴부타디엔고무블렌드 기반에너지함유 열가소성탄성체의 제조 및 특성

Abstract

Nitrile butadiene rubber (AN 함량 41%)의 nitrile기를 click reaction을 통해 tetrazole기로 변환시킴으로써 새로운 energetic polymer인 tetrazole-rubber를 제조하였다. 제조된 tetrazole-rubber를 ethylene-vinyl acetate(EVA) 또는 ethylene-co-butyl acrylate-co-glycidyl methacrylate(E-BA-GMA)에 tetrazole rubber 함량이 각각 50, 70wt%가 되도록 내부혼합기에서용융혼합하여 EVA/tetrazole-rubber 및 E-BA-GMA/tetrazole-rubber 블렌드를 제조하였다. 모폴로지 분석 및 열적특성 분석으로부터 tetrazole-rubber는 이들 에틸렌 공중합체와 특정상호작용을 가지며 에틸렌 공중합체가 연속상을 이루고 tetrazole- rubber가 수십 미크론 크기의 분산상을 이루는 모폴로지를 갖는 것을 알 수 있었다. 인장시험 및 유변학적특성 분석 결과 제조된 블렌드는 우수한 고무탄성과 용융가공성을 가짐을 알 수 있었으며, E-BA-GMA/tetrazole-rubber 블렌드의 경우에는 소량의 (1.0 phr 이하) DCP를 첨가함으로써 기계적물성 및 고무탄성을 향상시킬 수 있었다. 연소실험으로부터 제조된 블렌드에서 tetrazole-rubber의 함량이 증가할수록 연소 시 더 큰 에너지를 발산시킬 수 있음을 알 수 있었다. 이로부터 tetrazole-rubber와 에틸렌 공중합체 블렌드로부터 제조될 수 있는 에너지함유 열가소성 탄성체는 추진제용 고 에너지 바인더로써 활용 가능할 것으로 판단되었다.|Tetrazole containing rubber(tetrazole-rubber), an energetic polymer, was synthesized via a one-step process involving click reaction of commercially available NBR with sodium azide(NaN3). Blends of tetrazole-rubber with ethylene-vinyl acetate(EVA) and ethylene-co-butyl acrylate-co-glycidyl methacrylate(E-BA-GMA) were prepared by melt blending in an internal mixer with tetrazole-rubber content of 50 and 70 wt% in the blends. In the case of E-BA-GMA/tetrazole- rubber blends, small amount of dicumylperoxide(DCP) (less than 1.0 phr) was added during the melt mixing process. The morphology, thermal, mechanical and rheological properties were investigated. The phase morphology of all the blends examined by SEM revealed that tetrazole-rubber was dispersed in continuous olefin copolymer matrix. FT-IR and DSC showed that the tetrazole-rubber is partially compatible with the olefin copolymers. Addition of DCP in E-BA-GMA/tetrazole-rubber blends improved the compatibility between the components in the blends. Tensile test revealed that tensile modulus and strength were decreased with increasing tetrazole-rubber content in all the blends and tension set of all the blends is less than 10%, revealing that the blends are elastomeric. Rheological analysis revealed a typical shear thinning behavior in the blends, confirming that the blends behave like a thermoplastic elastomer. Combustion test showed that with increasing tetrazole-rubber content in the blends the higher energy is released. All the results obtained in this study exhibit that the polymer blending is an effective way to fabricate an energetic thermoplastic elastomer.; Tetrazole containing rubber(tetrazole-rubber), an energetic polymer, was synthesized via a one-step process involving click reaction of commercially available NBR with sodium azide(NaN3). Blends of tetrazole-rubber with ethylene-vinyl acetate(EVA) and ethylene-co-butyl acrylate-co-glycidyl methacrylate(E-BA-GMA) were prepared by melt blending in an internal mixer with tetrazole-rubber content of 50 and 70 wt% in the blends. In the case of E-BA-GMA/tetrazole- rubber blends, small amount of dicumylperoxide(DCP) (less than 1.0 phr) was added during the melt mixing process. The morphology, thermal, mechanical and rheological properties were investigated. The phase morphology of all the blends examined by SEM revealed that tetrazole-rubber was dispersed in continuous olefin copolymer matrix. FT-IR and DSC showed that the tetrazole-rubber is partially compatible with the olefin copolymers. Addition of DCP in E-BA-GMA/tetrazole-rubber blends improved the compatibility between the components in the blends. Tensile test revealed that tensile modulus and strength were decreased with increasing tetrazole-rubber content in all the blends and tension set of all the blends is less than 10%, revealing that the blends are elastomeric. Rheological analysis revealed a typical shear thinning behavior in the blends, confirming that the blends behave like a thermoplastic elastomer. Combustion test showed that with increasing tetrazole-rubber content in the blends the higher energy is released. All the results obtained in this study exhibit that the polymer blending is an effective way to fabricate an energetic thermoplastic elastomer.