Production of poly alpha-1,3-glucan films

1. A process for making a poly alpha-1,3-glucan film comprising:

(a) dissolving poly alpha-1,3-glucan in a solvent composition to provide a solution of poly alpha-1,3-glucan, wherein the solvent composition is selected from the group consisting of aqueous sodium hydroxide, aqueous potassium hydroxide, and aqueous tetraethyl ammonium hydroxide;

(b) contacting the solution of poly alpha-1,3-glucan with a surface;

(c) removing the solvent composition to form a poly alpha-1,3-glucan film; and

(d) determining the film to have at least one of:

(i) haze less than about 10%;

(ii) breaking stress from about 10 to about 80 MPa;

(iii) tear strength from about 250 to about 3000 gf/mm;

(iv) Gurley air permeability less than about 10 s; and

(v) oxygen permeation rate less than about 0.3 cc-mm/m 2 day at 23° C., 0% relative humidity (RH).

2. The process according to claim 1 , wherein the process further comprises the addition of a plasticizer additive to the solution of the poly alpha-1,3-glucan of step (a) and wherein the plasticizer additive is glycerol.

3. The process according to claim 1 , wherein the step (c) removing the solvent composition comprises evaporation and coagulation in water, acid or alcohol.

4. A poly alpha-1,3-glucan film made according to claim 1 .

5. The process of claim 1 , wherein the solvent composition is aqueous sodium hydroxide.

6. The process of claim 1 , wherein the solvent composition is aqueous potassium hydroxide.

7. The process of claim 1 , wherein the solvent composition is aqueous tetraethyl ammonium hydroxide.