The Graft Reaction Of Polysiloxane Containing Epoxy Group And Collagen Peptide With Narrow Molecular Weight Distribution

Collagen peptides are widely used as a result of non-toxic, hypoallergenicadvantages, biocompatible, biodegradable and many other advantages. But the poormechanical properties, brittleness and water solubility limit its applications. Currently,glutaraldehyde, polyfunctional epoxy-modified and other Functional group-modifiedand radical polymerization method was used to improve the local mechanical strengthand hydrophobic of the polypeptide material, but inhibits its flexibility and breathability.The epoxy silicone grafted polypeptide not avoid the above problems, and improve itsflexibility, thermal stability, hydrophobicity. Collagen polypeptide, the hydrolyzate ofcollagen, made a difficult for controlling the material properties as a result of the broadmolecular weight distribution. In this paper, firstly the narrow molecular weightdistribution polypeptide was obtained for a raw material to prepar a silicone epoxysiloxane grafted reaction-peptide film (PDMS-peptide film), membrane performanceresearched.Dialysis is the principal method for preparing a collagen polypeptide with thenarrow molecular weight distribution. The selection of dialysis conditions wasdiscussed, the concentration of collagen polypeptide2%, the concentration of NaClwas0.9mol/L, dialysis temperature was at45oC. Molecular weight distribution of thecollagen peptide tested by SDS-gel electrophoresis was40-100thousands.The effect of ratio, molecular weight silicone epoxy, reaction temperature, collagenpeptide concentration, pH and reaction time on the reaction of PDMS-E and collagenpeptide were investigated. Primary amine conversion rate was determined by Van Slykemethod. The structure of gelatin and Gel-PDMS copolymer were studied by FT-IRanalysis and XPS. The optimal reaction condition of the experiment was got by the wayof the orthogonal. Experimental results show that: PH at10.5, temperuture was at48℃,mole ratio was0.8:1, the reaction time was12h. Primary amino group can achieve thehighest conversion rate was58.62%.PDMS-peptide film prepared with slow solvent evaporation method was tested byTGA, DSC, DMA and contact angle measurement. TG showed that the conversion ofprimary amine is proportional to the thermal stability of modified membranepolypeptide; DSC and DMA results show flexibility was greatly improved, the doubleTg of DSC indicated the presence of the microphase-separated structure in membrane; Contact angle measurements of gas/liquid and solid/surface further illustrated the Sienrichment on gas/liquid, the hydrophobic of membrane enhanced.