DIFFERENTIAL SCANNING CALORIMETRY OF THE FIBER MADE FROM CASEIN-ACRYLONITRILE GRAFT COPOLYMER

The thermal behavior of milk casein-acrylonitrile graft copolymer (PM fiber) was investigated above 140°C in air by means of a differential scanning calorimetry (DSC). The DSC curve showed a broad endothermic hump due to dehydration (ca. 60-130°C), a sharp (ca. 300°C) and small (ca. 450°C) exotherms. The shape and type (i.e. exotherm) of the main peak closely resembles to that of acrylic fiber. However, the endothermic peak which should result from the casein part was not seen in the thermogram. This absence may be explained by scant endotherm of casein itself and the small casein content in PM fiber.From this and the previous results, the crystalline region in the copolymer seems to be composed of polyacrylonitrile sequences.