Synthesis and characterization of cationic copolymers of butylacrylate and[3-(methacryloylamino)-propyl]trimethylammonium chloride

Cationic copolymers of butylacrylate (BA) and [3-(methacryloylamino)-propyl ]trimethylammonium chloride (MAPTAC) were synthesized by free-radical-solut ion polymerization in methanol and ethanol. An FT-Raman Spectrometer and NM R were used to monitor the polymerization process. The copolymers were char acterized by light scattering, NMR, DSC, and thermogravimetric analysis. It was found that random copolymers could be prepared, and the molar fraction s of BA and cationic monomers in the copolymers were close to the feed rati os. The copolymer prepared in methanol had a higher molecular weight than t hat prepared in ethanol. As the cationic monomer content increased, the gla ss-transition temperature (T-g) of the copolymer also in creased, whereas t he thermal stability decreased. The reactivity ratios for the monomers were evaluated. The copolymerization of BA (M-1) with MAPTAC (M-2) gave reactiv ity ratios such as r(1) = 0.92 and r(2) = 2.61 in ethanol as well as r(1) = 0.79 and r(2) = 0.90 in methanol. This study indicated that a random copol ymer containing a hydrophobic monomer (BA) and a cationic hydrophilic monom er (MAPTAC) could be prepared in a proper polar solvent such as methanol or ethanol. (C) 2001 John Wiley & Sons, Inc.