Nonisothermal Crystallization Kinetics and Dynamic Rheological Behavior of Concentrated Thermoplastic Vulcanizates ( TPVC )

ABSTRACT Soft‐grade ethylene propylene diene monomer/polypropylene (EPDM/PP) thermoplastic vulcanizates (TPVs) suffer from compromised processability and unstable phase morphology due to high rubber loading and oil extension. Herein, we report a concentrated thermoplastic vulcanizate (TPVC) masterbatch strategy via peroxide‐mediated dynamic vulcanization of highly oil‐extended EPDM and PP, enabling flexible hardness tuning via PP dilution. The nonisothermal crystallization kinetics of the PP matrix in TPVC was systematically quantified via the Jeziorny‐modified Avrami model, Mo model, and Kissinger method, revealing a dual effect of dispersed EPDM phase: accelerating PP crystallization via heterogeneous nucleation (crystallization activation energy reduced by 22.36 kJ/mol vs. pure PP) while restricting chain mobility. Dynamic rheological tests combined with time–temperature superposition (TTS) analysis (Han and van Gurp‐Palmen curves) confirmed that the T80P20 system fully conforms to the TTS principle with a broad processability window, and all formulations exhibit elasticity‐dominated viscoelastic behavior (phase angle ≤ 20°). This work provides quantitative kinetic and rheological guidance for industrial processing optimization of soft TPVs.