The invention relates to a modified
gelatin gradient film prepared from mixed
glycidol and single-
epoxy-terminated polysiloxane. A method for preparing the modified
gelatin gradient film includes dissolving surfactants in water to prepare
aqueous solution; adding
gelatin into the
aqueous solution under the conditions of the temperatures of 40-60 DEG C and the pH (potential of
hydrogen) of 8-11; stirring the gelatin and the
aqueous solution for 4-8 h and then adding the single-
epoxy-terminated polysiloxane into the gelatin and the aqueous solution continuously or in batches to obtain mixtures; carrying out reaction for 12-30 h and then adding
glycidol into the mixtures; continuing to carry out reaction at the temperatures of 40-60 DEG C for 6-12 h to obtain milk white turbid liquid; adding ethyl
alcohol into the milk white turbid liquid and uniformly mixing the ethyl
alcohol with the milk white turbid liquid to obtain mixed liquid; dripping 0.5-0.8 ml of the measured mixed liquid on gelatin substrates; allowing the gelatin substrates to stand still for 12-18 h and then freezing the gelatin substrates by the aid of
liquid nitrogen;
drying the gelatin substrates by the aid of a freeze dryer to obtain the gradient film. The dosage of the gelatin is 1-10% of the
mass of the aqueous solution. The dosage of the single-
epoxy-terminated polysiloxane is 0.2-1.0 times the
molar weight of the gelatin. The dosage of the
glycidol is 0-1 times the
mass of the single-epoxy-terminated polysiloxane. A volume ratio of the ethyl
alcohol to reaction liquid is (3-5):1. The modified gelatin gradient film has the advantages that the concentration of components of the modified gelatin gradient film changes in longitudinal sections in a gradient manner, the modified gelatin gradient film is high in tensile strength and good in hydrophobic property and is soft, and the like.