Giant Spherulite Formation in Amorphous Polyanion Membrane by Photopolymerization on Gelatin Matrix

In-bulk photopolymerization of 2-acylamido-2-methylpropanesulphonic acid (AMPS) on gelatin matrix was made by ultraviolet irradiation at room temperature to form the crystalline and flexible membranes with giant spherulites (maximal radius: 2.2 cm). Number- and weight-average molecular weights of PAMPS were 79,500 and 138,000, respectively. The melting point of the membrane was around 200 °C. The giant spherulite formation was discussed on the basis of the PAMPS chain formation and PAMPS/gelatin complexation.