Morphology evolution of photoluminescent crosslinked copolymer of maleic anhydride and a-methyl styrene with nonsolvent-induced reaction media changes

Abstract

Monodisperse crosslinked polymer particles of maleic anhydride and a-methyl styrene with different morphology were prepared in different reaction media by the method of self-stabilized precipitation polymerization, and the obtained crosslinked polymer particles exhibited photoluminescence. The content of reaction media was tuned by addition of nonsolvent into isoamyl acetate, and the polymer exhibited proper morphology at proper reaction media composition. Smooth microspheres, dumbbell-like particles, pumpkin-like particles, aggregated particles and cluster of small polymer particles, aggregated cluster of polymer particles appeared with increasing in the addition of nonsolvent, and same tendency about morphology evolution was also observed with increasing in the absolute value of solubility parameter difference value between isoamyl acetate and used mixed solvent. Different nonsolvent owns different influence on the morphology of polymer. Polymer with different morphology prepared in different reaction media exhibits different photoluminecsent behavior. Polymers in proper reaction media in which polymer is single microsphere or particles with proper shape can exhibit strong emission excited by proper light, and polymers with morphology of aggregated particles prepared in mixed solvent containing high percentage (above 80 wt%) of nonsolvent show weak emission. In poorer reaction media, with the addition of DVB, much more repeating units derived from DVB and MAH result in the weakness of photoluminescence.