Abstract
Studies were made on the structural analysis of the silk thread, modified by the potassium persulfate initiated graft copolymerization of methacrylamide (MAA), by means of differential scanning calorimetry (DSC), thermogravimetry (TG), X-ray diffraction measurement and scanning microscopic observation. By examining the DSC curves of modified silk thread by MAA grafting, the compatibility of MAA grafting-polymer against to the silk fibroin was found to be very low. The percentage of grafting could be estimated roughly from the enthalpic changes appeared on the DSC curves at about 270°C. X-ray diffraction patten of chemically modified silk by graft polymer was masked by the Debye-Scherrer ring from the diffraction of graft polymer, when the percentage of grafting exceeded the limit by about 40%. Polymethacrylamide appeared to be chemically bonded to the surface of the silk thread, when the percentage of grafting exceed 40%. The decompositional temperature of the modified silk thread decreased as the grafting reaction underwent, while the crystal structure stayed unchanged.
