Synthesis and Characterization of Carboxylic Acid and Iodine End Functional Polymers By Reverse Iodine Transfer Polymerization

Carboxyl-functional (co)polymers of styrene and acrylonitrile were synthesized via reverse iodine transfer (co)polymerization (ritp) in the presence of iodine and 4,4’-azobis(isocyanovaleric acid) (acva) as in situ chain transfer agent and initiator, respectively# the average molecular weight, molecular weight distribution (ɖ) and (co)polymer structure (e#g# copolymer composition and polymer chain end group) were characterized using gel permeation chromatography (gpc), fourier transform infrared (ft-ir) spectroscopy, proton nuclear magnetic resonance (1h-nmr) spectroscopy and acid-base titration# the results showed that the (co)polymerizations were successfully performed by ritp with the characteristics of controlled radical polymerization (crp) such as predetermined number average molecular weight, relatively narrow molecular distribution (ɖ<1#5) and carboxyl- and iodine- functionality (fcooh and fi ) of about one for every polystyrene and polystyrene-acrylonitrile chain#