The invention discloses a method for preparing a high-
toughness cottonseed protein based
composite membrane. The method comprises the following steps: (1) refining
cottonseed protein; (2) preparing acottonseed
protein solution and a water-soluble
high polymer solution; (3) adding the
cottonseed protein solution into the water-soluble
high polymer solution, and carrying out uniform stirring at a certain temperature, so as to obtain a solution A; (4) adding a
tertiary amine based alcoholic
reagent into the solution A, and carrying out stirring for 1 to 5 hours in a thermostatic water bath withthe temperature of 40 DEG C to 60 DEG C, so as to obtain a solution B; and (5) after the solution B is cooled, preparing the cottonseed protein based
composite membrane with relatively good toughnessby a
casting method. Water-soluble high polymers include, but not limited to,
polyvinyl alcohol,
polyethylene oxide and
gelatin; the addition level of the
tertiary amine based alcoholic
reagent is 5%to 30% the total
mass of the cottonseed protein and the water-soluble high polymers; and a
mass ratio of the cottonseed protein to the water-soluble high polymers is (9: 1) to (1: 9). According to themethod, on one hand, the
tertiary amine based alcoholic
reagent serves as a
plasticizer, and thus, the elongation at break of the protein membrane is increased; and on the other hand, the
tertiary amine based alcoholic reagent serves as a physical cross-
linker, cross-linked bridges are formed between molecular chains of the cottonseed protein and the high polymers through
hydrogen bonds under theaction of
tertiary amine groups with relatively high
electronegativity, a novel cross-linked network is formed, and thus, the tensile strength of the protein membrane is enhanced. Thereby, the high-
toughness cottonseed protein based
composite membrane is prepared.