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

The hydrolysis and overall water‐crosslinking kinetics of vinyltrimethoxysilane‐grafted ethylene–propylene copolymer (EPR‐ g ‐VTMS) containing boron trifluoride monoethylamine complex (BF 3 –MEA), boron trifluoride methanol complex (BF 3 –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 BF 3 –MEA provided much lower activation energy for the hydrolysis reactions than that of DBTL; however, BF 3 –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 BF 3 –MEA results in the displacement of SiOCH 3 groups via an S N 2‐Si mechanism.