Head-to-Head Polymers

Head-to-head polymers of α-olef ins, vinyl and acrylic monomers synthesized by indirect methods have shown similarities and differences in some of their behavior when compared to their counterparts of the common head to tail polymers. Head-to-head polyole-fins, such as polystyrene or polypropylene, were prepared by 1,4-polymerization of the corresponding 2,3-disubstituted butadienes-1,3 followed by hydrogenation of the remaining double bonds, polyacrylates by alternating copolymerization of ethylene and maleic anhydride, followed by esterification of the polymer. Head-to-head polyacrylates were reduced to poly(allyl alcohols) which were then acrylated to the acetates and benzoates. Head-to-head polyvinyl halides) were obtained from 1,4-polybutadiene by chlorination or bromination. The head-to-head polymers were characterized by spectroscopic analysis, some molecular weight characterization was done, and their thermal behavior was studied. The blending behavior with the corresponding head-to-tail polymers was studied in some cases; in others (head-to-head polystyrene), the blending with other polymers was investigated and the codegradation of the polymers was evaluated.