Accelerated Silane Water‐Crosslinking Kinetics of Ethylene–Propylene Copolymer by Boron Trifluoride Complexes

Abstract

AbstractThe hydrolysis and overall water‐crosslinking kinetics of vinyltrimethoxysilane‐grafted ethylene–propylene copolymer (EPR‐g‐VTMS) containing boron trifluoride monoethylamine complex (BF3–MEA), boron trifluoride methanol complex (BF3–MeOH), or di‐n‐butyltin(II) dilaurate (DBTL) as a silane‐crosslinking catalyst was followed by ATR‐FT‐IR and measuring the gel fraction, respectively. Kinetics results by ATR‐FT‐IR technique showed that using BF3–MEA provided much lower activation energy for the hydrolysis reactions than that of DBTL; however, BF3–MeOH had little catalytic effect on both the hydrolysis and overall water‐crosslink reaction of EPR‐g‐VTMS. We propose that the actual catalytic effect of ethylamine molecule dissociated from BF3–MEA results in the displacement of SiOCH3 groups via an SN2‐Si mechanism.magnified image