Olefin copolymerization via controlled radical polymerization : copolymerization of methyl methacrylate and 1-octene

The atom transfer radical (co)polymerization (ATRP) of methyl methacrylate (MMA) with 1-octene was investigated. Well controlled homopolymer of MMA was obtained with 2,2,2-trichoroethanol (TCE) and p-toluenesulfonyl chloride (pTsCl), although, uncontrolled copolymerization occurred when pTsCl was employed in the presence of higher mole percent of 1-octene in the monomer feed. Well-controlled copolymers constituting almost 20 mol % of 1-octene were obtained using TCE as initiator. Narrow molar mass distributions (MMDs) were obtained in the ATRP experiments. The comparable free radical (co)polymerizations (FRP) resulted in broad MMDs. Increasing the mol % of the olefin in the monomer feed, led to an increase in the level of incorporation of the olefin in the copolymer, at the expense of the overall percent conversion. The formation of the copolymer was established using matrix assisted laser desorption/ionization-time-of-flight-mass spectrometry (MALDI-TOF-MS). Evident from the MALDI-TOF-MS spectra was that most polymer chains contained at least one 1-octene unit. The glass transition temperature of the copolymer was 16 C lower than that for the homopolymer of MMA. Block copolymer was synthesized and further characterized using gradient polymer elution chromatography (GPEC). The shift in the retention time between the macroinitiator and the formed block, clearly indicated the existence of the block copolymer structure and also confirmed the high macroinitiator efficiency