A direct functionalization of polyolefins for blend compatibilization by an insertion of 1,1-bis(phenylsulfonyl)ethylene (BPSE)
Using recently developed C–H insertion chemistry, a mild post-modification of polyethylene (PE), hyperbranched polyethylene (HBPE) and isotactic polypropylene (iPP) to insert phenylsulfonyl groups was performed. The Michael-type radical addition applies 2-chloroanthroquinone (2-CIAQ) as a C–H bond-cleaving photocatalyst and 1,1-bis(phenylsulfonyl)ethylene (BPSE) as the olefinic substrate. The reactions were performed in solution with various feed ratios and the products were characterized by multi-instrumental analysis. The modification is a convenient one-step introduction of aromatic moieties along polyolefin chains. By optimization of the reaction conditions, as many as 18.5 graft units of BPSE were introduced per 100 ethylene repeating units. The modified samples were successfully demonstrated to act as a compatibilizer between blends of PE/iPP and polystyrene (PS) as verified by scanning electron microscopy (SEM).