Title : Processing–structure–rheology relationships in nanoclay-reinforced recycled EPDM/PA12 nanocomposites

The accumulation of end-of-life rubber waste necessitates sustainable recycling to create valuable engineering materials. This study explored the impact of processing strategy, residence time, nanoclay loading, and recycled ethylene propylene diene monomer (EPDM) on the properties of polyamide 12 (PA12)/Cloisite® 30B nanocomposites, produced via melt mixing at 200 °C. Three processing methods were tested: simultaneous melt mixing (M0), PA/clay masterbatch followed by EPDM incorporation (M1), and PA/EPDM masterbatch followed by clay addition (M2). A residence time of 6 minutes was critical for optimal EPDM dispersion and clay exfoliation. M0 achieved the best EPDM dispersion and clay exfoliation, while M2 exhibited inferior elastomer distribution. Nanoclay loadings up to 3 wt.% improved EPDM distribution, but 5 wt.% caused clustering due to steric hindrance. Rheological analyses indicated that the clay network and EPDM interactions defined the ternary composites' viscoelastic behavior, shifting from solid-like to elastomer-dominated as EPDM content increased, while maintaining good processability.

Engr. Dr. Friday Nwankwo Archibong is an engineer specializing in materials science research and environmental stability. He holds a PhD in envirnmental and materials science from Nnamdi Azikiwe University and Masters inengineering from University of Nigeria, Nsukka. Engr. Dr. Archibong has worked with INSA-CVL, France, EBSU in Nigeria and has published extensively on materials science, nanotechnology and environment. He is currently the Head of Department, Mechanical Engineering Program at the Alex Ekwueme Federal University Ndufu-Alike Ikwo, Ebonyi State, Nigeria.