Preparation of Poly(t-butyl methacrylate)-Polyimide Particles by Dispersion Polymerization of t-Butyl Methacrylate Using Poly(amic acid) as a Stabilizer and Subsequent Imidization

Dispersion polymerization of t-butyl methacrylate (BMA) and a cationic comonomer, 4-(vinylbenzyl)trimethylammonium chloride (VBA) was conducted in alkaline aqueous ethanol using various aromatic poly(amic acid)s (PAA) as stabilizers. The monodisperse particles were obtained in high yield using the optimum composition of solvent mixture depending on the PAA structure. By using a cationic comonomer (VBA), PAA was quantitatively incorporated into the particles. The imidization of PAA on the particles proceeded with acetic anhydride and 4-(dimethylamino)pyridine to form PBMA-polyimide (PBMA-PI) particles. The PBMA-PI particles were maintained in spherical shape by the thermal treatment up to 280 degrees C.