Research On The Blends Of Poly(L-lactic Acid)/Silk Fibroin

Poly(lactic acid) (PLA) was artificially synthesized with the starch of natural cereal as its raw material. It is linear aliphatic thermoplastic polyester and environmentally benign material, which attracts many researchers to widely research. The silk fibroin (SF) with the endophilicity to the human body cell which also came from natural protein fiber contained 18 types of amino acid can be used to modify PLA materials to enhance the biological compatibility of PLAs. So that it would enhance the application area of PLA materials.In this paper, four kinds of PLLA samples were used as the base constituents, add SF by the proportion PLA:SF=8:2,6:4,4:6,2:8 (w/w) in the PLLAs to be polymer blend. Rotational viscometer, Ubbelohde viscometer, Fourier transformed infrared(FT-IR), differential scanning calorimetry(DSC), polarizing microscope (PLM) and scanning electron microscope(SEM) were employed for the characterization of polymers obtained. Though the analysis of all the experimental data, we can discuss changes of dynamic viscosity, molecular structure, thermodynamic property and crystal morphology, in order to approach the property varieties after blending modification.The results demonstrated that there was some act on each other, so that the two components got a good compatibility. In the blends, as the increasing content of SF, crystallization of PLLA was becoming weaker. When the weight percent was 80%, the two were almost incompatible. So that the blend can be used to make the materials with cell compatibility and druggery delayed release functions in many application areas.