Scholarlink

<p>Ethylene propylene diene monomer–polypropylene (EPDM–PP) thermoplastic vulcanizates (TPVs) are increasingly deployed as recyclable substitutes for conventional crosslinked EPDM in outdoor seals and gaskets. Yet, their long-term weathering degradation remains mechanistically unresolved. In this study, extended accelerated weathering (ASTM G154 Cycle 7; coupled UV–moisture–heat) is combined with controlled variations in exposure temperature and precipitation, and EPDM–PP is directly benchmarked against a hardness-matched EPDM. Results show that EPDM–PP does not follow the monotonic decay typical of EPDM; instead, performance evolves through a two-stage trajectory comprising (i) an extended “induction” regime with retention of tensile properties and minimal stiffening, followed by (ii) an abrupt property collapse once a critical threshold is reached at elevated temperature. SEM/EDS/FTIR analyses indicate that this transition is governed by phase-specific degradation: EPDM fragmentation is suppressed during the induction period by the TPV microstructure, whereas photo-oxidative degradation of the PP domain ultimately triggers crack growth, oxidation-driven mass loss, and rapid loss of load-bearing area. By identifying the PP phase as the durability-limiting component and delineating its “cliff-edge” failure mode, this work establishes a mechanistic framework for predicting EPDM–PP service reliability and for designing TPVs with extended outdoor lifetimes.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Phase-specific weathering degradation mechanisms in EPDM–PP thermoplastic vulcanizates

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年7月4日

查看全文
  • Felipe Basquiroto de Souza,
  • Sze Dai Pang

摘要

Ethylene propylene diene monomer–polypropylene (EPDM–PP) thermoplastic vulcanizates (TPVs) are increasingly deployed as recyclable substitutes for conventional crosslinked EPDM in outdoor seals and gaskets. Yet, their long-term weathering degradation remains mechanistically unresolved. In this study, extended accelerated weathering (ASTM G154 Cycle 7; coupled UV–moisture–heat) is combined with controlled variations in exposure temperature and precipitation, and EPDM–PP is directly benchmarked against a hardness-matched EPDM. Results show that EPDM–PP does not follow the monotonic decay typical of EPDM; instead, performance evolves through a two-stage trajectory comprising (i) an extended “induction” regime with retention of tensile properties and minimal stiffening, followed by (ii) an abrupt property collapse once a critical threshold is reached at elevated temperature. SEM/EDS/FTIR analyses indicate that this transition is governed by phase-specific degradation: EPDM fragmentation is suppressed during the induction period by the TPV microstructure, whereas photo-oxidative degradation of the PP domain ultimately triggers crack growth, oxidation-driven mass loss, and rapid loss of load-bearing area. By identifying the PP phase as the durability-limiting component and delineating its “cliff-edge” failure mode, this work establishes a mechanistic framework for predicting EPDM–PP service reliability and for designing TPVs with extended outdoor lifetimes.