Microcapsules with compact membrane structure from gelatin and styrene–maleic anhydride copolymer by complex coacervation

Stable, uniform, and spherical microcapsules were prepared from gelatin and a hydrolyzed copolymer of styrene and maleic anhydride (SMA) by complex coacervation. The gelatin/SMA microcapsules were characterized in terms of microstructure, morphologies, thermal stability, and release behavior by scanning electron microscopy (SEM), optical microscopy, and thermogravimetric analysis (TGA). It is demonstrated that the membranes of the microcapsules are formed from nano-sized coacervate droplets resulting from gelatin and hydrolyzed SMA, which leads to a compact membrane structure.