Alternating ethylene–alkyl acrylate copolymers. I. polymer preparation

High molecular weight alternating ethylene–ethyl acrylate copolymers were prepared by using boron trifluoride to complex the acrylate ester. The polymerizations were run under mild conditions (25–50°C, 6–20 atm ethylene) in dichloromethane or dichloroethane solution with free-radical initiation. At lower ethylene pressures or at less than stoichiometric levels of BF₃, the polymers are acrylate-rich. This is due to ethyl acrylate homopolymerization competing with the copolymerization reaction. The effect of other polymerization variables is also discussed.