Synthesis of Diacetone Acrylamide Monomer and the Film Properties of Its Copolymers

Diacetone acrylamide (DAAM) was derived from alkaline hydrolysis of 2-methyl-4-oxo-N-[(1Z)-1(sulphooxy)prop-2-ene-1-ylidene]pentan-2-aminium as a precursorwhich the latter was prepared by condensation of acrylonitrile and acetonein sulphuric acid. Diacetone acrylamide was characterized by 1H NMR, FTIR and massspectrometry for structural conformation. The DAAM copolymer emulsions wereprepared by a two-stage seed batch emulsion polymerization of methyl methacrylate,butyl acrylate and DAAM using ammonium persulphate as an initiator, sodium laurylsulphate and nonyl phenol as emulsifiers. Diacetone acrylamide was used as afunctional monomer. Further, the DAAM copolymer emulsions were characterized andstudied as a function of DAAM concentration by laser light scattering, viscometry anddifferential scanning calorimetry. The results have shown that with increasedconcentration of DAAM in the emulsions there are increases in particle size, particlesize distribution and viscosity of the emulsions, whereas the glass transitiontemperature (Tg) of DAAM emulsions is reduced. These emulsions comprising differentconcentrations of DAAM were cross-linked with 1,3-diaminopropane and werecharacterized by FTIR. The cross-linking reaction was carried out at ambienttemperature resulting in formation of one-component thermoset acrylic emulsions.These emulsions which were used as coatings were evaluated for mechanical andchemical resistance properties. The results obtained showed that the coatingcomprised of 4 wt% of DAAM in copolymer emulsion exhibited improved chemicalresistance and mechanical properties.