N-Vinylformamide as a route to amine-containing latexes and microgels

Abstract.Amine-containing poly(N-isopropylacrylamide) (PNIPAM) microgels and polystyrene-core-polyvinylamine-shell latexes were prepared by copolymerization with N-vinylformamide (NVF) followed by acid hydrolysis. Semi-batch methods were required to incorporate NVF into the gels or onto the latex. This requirement is in contrast to the behavior of acrylamide, which is an isomer of NVF and has similar polymerization rate constants in water. The highest yields of incorporated NVF were less than 50% for both microgels and latex. It is proposed that NVF does not partition as much as acrylamide in the PNIPAM particles during polymerizations. In the case of the PS latex, it is proposed that poly(N-vinylformamide) (PVNF) formed in solution is not very susceptible to hydrogen abstraction, which is necessary to form polystyrene grafted-PVNF.The formamide moieties in the microgels and latex shells were converted to amine groups by acid hydrolysis. However, we were unable to achieve more than 50% hydrolysis. Thus, NVF is a route to amine-containing gels and amine-coated polystyrene particles, however, the reactions are not efficient.