A Synergistic Compatibilization Strategy for NBR/PA6 Blends with Ethylene-Butadiene-Fluorostyrene Multiblock Terpolymer

Abstract

Nitrile rubber (NBR) offers exceptional oil resistance and high elasticity while polyamide 6 (PA6) provides outstanding mechanical strength and thermal stability, which allows to make high performance blends for advanced engineering applications but is frustrated by the inherent thermodynamic immiscibility and obvious phase separation. Herein, we reported the preparation of ethylene-butadiene-para-fluorostyrene (E-BD-S F ) multiblock terpolymers via coordination polymerization using thioanisole ligated lutetium complexes. The terpolymers strategically incorporate para-fluorostyrene (S F ) units capable of forming hydrogen bonds and dipole-dipole interactions with PA6, along with ethylene (E) units that enhance chain entanglement, while the consecutive butadiene (BD) segments are intrinsically compatible with BD-enriched NBR to co-form covalent sulfur-anchored bridges during vulcanization process. With the addition of 1.5 wt % E-BD-S F , the compatibilized NBR/PA6 blends show remarkable mechanical properties, where the elongation at break doubles to 235 ± 10.60%, tensile strength reaches 17.86 ± 0.45 MPa, and tear strength enhances to 66.06 ± 7.14 kN/m as well as improved thermal stability, while the excellent solvent resistance is maintained. This work presents a synergistic compatibilization approach based on multiblock terpolymers that integrate physical interactions with chemical bonding, providing a versatile platform for the development of high-performance polymer blends.