Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE Cold plasma functionalization of EFB fibers using various alcohol precursors, with propanol achieving the optimal compatibility with rPE and improves composite performance through a short-time, low-chemical process.

ABSTRACT
Utilizing oil palm empty fruit bunch (EFB) waste as reinforcement in recycled polyethylene (rPE) offers a sustainable approach to composite development. However, the hydrophilic nature of EFB limits its compatibility with hydrophobic rPE, resulting in poor interfacial adhesion and reduced mechanical performance. Conventional chemical surface modification methods can improve compatibility but often raise environmental concerns. In this study, a greener alternative based on atmospheric cold plasma using alcohol-based precursors (ethanol, isopropanol, and isobutanol) was employed to enhance EFB–rPE compatibility. Surface characterization revealed a reduction in surface hydroxyl groups and the formation of ether bonds, leading to increased fiber hydrophobicity. Isopropanol exhibited the most effective modification, increasing the water contact angle from 67.66° to 85.59° and reducing the surface tension mismatch with rPE from 27.87% to 4.29%. The modified EFB fibers were incorporated into rPE/EFB composites by varying the proportion of modified to unmodified fibers at a constant total fiber content. Morphological analysis confirmed improved fiber–matrix adhesion and reduced interfacial gaps. Overall, mechanical performance was enhanced, particularly at 10%–50% modified EFB. Crystallization kinetics analysis further demonstrated that modified EFB also acts as a nucleating agent, influencing the crystallization and contributing to the improved mechanical properties of rPE-based biocomposites.