Synthesis and characterization of secondary amine functional microparticles

Secondary amine functional microparticles were prepared by the suspension polymerization of styrene (STY), divinylbenzene (DVB), and 2-(tert-butylamino)ethyl methacrylate (tBAEMA). Effects of polymerization parameters (such as polymerization time, stirring speed, temperature, STY, DVB, tBAEMA, initiator and stabilzer concentrations, etc.) on experimental amine content, average particle size, and particle size distribution were determined. The suspension polymerization experiments were carried out in three different systems. In the first one, conventional suspension polymerization system was used and the organic phase including monomers and initiator was dispersed in an aqueous medium by using sodium dodecylsulfate (SDS) as the stabilizer. In the second system, a similar experimental protocol was followed except a proper amount of Al2(SO4)3 was used to replace SDS in the dispersion medium. The third method used to prepare the secondary amine functional microparticles was again similar to first polymerization protocol, except a proper amount of Al2(SO4)3 was added to the aqueous dispersion medium as a co-stabilizer. When SDS was used alone as a stabilizer, polymerization product was agglomerated; individual and spherical microparticles were not obtained. Replacement of SDS with Al2(SO4)3 resulted spherical microparticles within the size range of 50 - 200 µm. When SDS and Al2(SO4)3 was used together, again individual and spherical microparticles were obtained within the size range of 130 - 250 µm.