Silk fibers were chemically modified by grafting with polyethylene glycol dimethacrylate(PEGDMA)．The structure and thermal properties of these grafted silk fibers were investigated in relation to the graft yield by using DSC

TGA and dynamic viscoelastic measurements．The DSC and TGA results showed that the decomposition peak of grafted silk fibers shifted to higher temperatures

suggesting that grafting of silk fibers with PEGDMA can improve the thermal stability．Dynamic mechanical data showed that the major loss peak became broader and its temperature shifted to lower values following the increase of the graft yield．The cross-linkage between the molecules of silk fibers and PEGDMA may limit macromolecular motion in silk fibers

so

the peak of loss modulus (E″) determined by dynamic viscoelastic measurements became lower and the initial position of this peak shifted to higher temperature

when the graft yield increased.