Latex syntheses using novel tertiary amine methacrylate-based macromonomers prepared by oxyanionic polymerization

Recently, Nagasaki et al. [Macromol. Rapid Commun. 1997, 18, 827-835] repor ted that certain heteroatom methacrylate monomers such as 2-(diethylamino)e thyl methacrylate (DEAEMA) can be polymerized at room temperature using oxy anionic initiators such as potassium ethoxide. Furthermore, functional init iators such as potassium 4-vinylbenzyl alcoholate produced styrene-function alized macromonomers. We have utilized this chemistry to synthesize a range of novel, well-defined water-soluble macromonomers based on 2-(dimethylami no)ethyl methacrylate (DMAEMA) and other tertiary amine methacrylates. Thes e macromonomers were typically contaminated with small amounts of residual initiator, but this could be easily removed by precipitation into n-hexane. NMR and GPC studies confirmed that each poly(DMAEMA) chain had a polymeriz able styrene end group. Selected macromonomers were used to prepare submicr ometer-sized and micrometer-sized polystyrene latexes via aqueous emulsion and nonaqueous dispersion polymerization, respectively. The terminal functi onal group participates in the styrene polymerization, leading to chemical grafting of the macromonomer onto the outside of the latex particles. The p resence of the stabilizer in the latexes was confirmed by FTIR spectroscopy and nitrogen microanalyses. The adsorbed amount of macromonomer varied bet ween 0.5 and 4.6 mg m(-2) The first examples of well-defined, sulfobetaine- based macromonomers were obtained by derivatizing selected DMAEMA macromono mers with 1,3-propane sultone. One of these macromonomers proved to be an e ffective steric stabilizer for the synthesis of polystyrene latexes at high electrolyte concentration (1.0 M NaCl).