Synthesis and characterization of novel polymers containing sulfur from 3-mercaptopropionic acid

Three new monomers, 2-hydroxyethoxycarbonylethyl methoxycarbonylethyl sulfide (HEMS), 2-hydroxyethoxycarbonyl (2'-methyl) ethyl methoxycarbonylethyl sulfide (HMMS), and 3,3'-dithiodiethylcarboxy allyl (DTCA) were synthesized from 3-mercaptopropionic acid (3-MPA) or methyl 3-mercaptopropionate (M3-MP). Polycondensations of HEMS and HMMS were performed with several metal acetates as catalysts to obtain the corresponding polythioethers with number average molecular weights (M-n) of up to 6.4x10(3). Radical polymerizations of DTCA were carried out in bulk at 110 degrees C to obtain polymers having allyl groups in the side chain. Polymerizations of DTCA with ethylene diamine (EDA) or hexamethylene diamine (HDA) were performed under various conditions to obtain the corresponding polymers. Decomposition temperatures (T-d) and glass transition temperatures (T-g) of the polymers were 146-252 degrees C and -54 - 1 degrees C, respectively. Crystallinity of the polymers obtained by polymerizations of DTCA with EDA and HDA was 25 - 49%.