Poly(methylmethacrylate) microspheres with matting characteristic prepared by dispersion polymerization

Herein, poly(methyl methacrylate) (PMMA) microspheres with different size and distribution were synthesized via one-step dispersion polymerization, using methyl methacrylate (MMA), polyvinylpyrrolidone (PVP), and sodium styrene sulfonate (NaSS) as monomer, stabilizer, and co-monomer, respectively. The influence of MMA, PVP, and NaSS concentrations on the particle size and distribution of PMMA was investigated. The results showed that an increase of NaSS or PVP concentrations; the size of PMMA microspheres tended to decrease while increasing the MMA concentration led to large particle size and wide distribution. In order to evaluate matting effect of PMMA microspheres, artificial leather was used as the base, which was coated by waterborne polyurethane (WPU) mixture with PMMA microspheres. The matting effect was significantly determined by the size scale of PMMA microspheres. With increasing the particle size of microspheres, the gloss of coatings surface gradually decreased. Further mechanism study indicated that PMMA microspheres mounted on the surface of WPU coatings thus making the coating surface rough and bumpy was the reason for obtaining coatings with matting effect. Rough surface leads incident light to scatter rather than reflecting, which was the nature for matting effect of present PMMA microspheres.