Isobornyl Methacrylate as a Reactive Solvent of Polyethylene

Abstract

Solutions containing 15 wt % of a low-molar-mass polyethylene (PE) in isobornyl methacrylate (IBoMA), containing 0, 5 or 10 wt % of 1,4 butanediol dimethacrylate (BDDMA) as crosslinker, were polymerized using either benzoyl peroxide (BPO), at 80 ºC, or dicumyl peroxide (DCPO), with a thermal cycle attaining 150 ºC, as initiators. Phase separation of an amorphous PE-rich phase took place when carrying out the reaction at temperatures higher than the PE melting temperature. Partial crystallization of PE was observed when cooling to room temperature. Depending on the initial amount of BDDMA, the fraction of PE that was phase separated varied between 57 % and 66 % of the initial amount, with crystalline fractions in the range of 15 % to 42 %. The use of IBoMA as a reactive solvent of PE has two main advantages over other reactive solvents reported in the literature: a) it has a very low vapor pressure, and b) its free-radical polymerization gives a polymer with a relatively high glass transition temperature.