SYNTHESIS AND CHARACTERIZATION OF COPOLYMERS OF STYRENE AND N-METHYLOLACRYLAMIDE

Copolymers of styrene (ST) and N-Methylolacrylamide (NMA) were synthes ized by emulsion polymerization for different initial weight ratios of ST/NMA. Fast reaction rates and high conversions are achieved regardl ess of the ST/NMA ratio. NMA content in copolymers, as deduced by DSC, FTIR and Kjeldhal analysis, is higher as the initial ST/NMA ratio dec reases. Glass transition temperature of copolymers increases as the ST /NMA ratio decreases and it decreases with reaction time for a fixed S T/NMA ratio. The latter results and FTIR spectra as well as Kjeldhal a nalysis as a function of reaction time indicate that NMA reacts initia lly in the aqueous phase, after which ST, because of its overall large r concentration, is incorporatated preferentially in the polymer.