Using Sodium Salt of Partially Hydrolyzed Poly(t-butyl acrylate) of Specific Molecular Weights as a Component or a Single Surfactant in Emulsion Polymerization

Poly(t-butyl acrylate) (PtBA) samples with fixed number average molecular weights (Mn) were prepared by anionic polymerization. The PtBA samples were further hydrolyzed in DMF solvent in the presence of p-toluenesulfonic acid (PTSA) to have a 15% of hydrolysis, and neutralized to sodium salt; the products are termed as PANa. The PANaT was neutralized from PAA, which was made from a solution polymerization of acrylic acid. It was found possible to perform the miniemulsion polymerization of styrene using either PANa12 (Mn =12.0 × 10^4) or PANaT (Mv= 2.4 × 10^5) as the sole emulsifier. In the absence of sodium dodecyl sulfate (SDS), the product latexes have average diameters of 364 and 395 nm, almost tenfold larger as those products in the presence of SDS. The particle diameters affect the radical number to coexist in the particles, and therefore, affect the average molecular weights of polymer.