Regioselectively substituted cellulose esters

A film comprising a regioselectively substituted cellulose ester comprising:

• (i) a plurality of R1—CO— substituents;
• (ii) a plurality of R4—CO— substituents;
• (iii) a plurality of hydroxyl substituents,
• wherein the degree of substitution of R1—CO— at the C2 position (“C2DSR1-CO”) is in the range of from about 0.2 to about 1.0,
• wherein the degree of substitution of R1—CO— at the C3 position (“C3DSR1-CO”) is in the range of from about 0.2 to about 1.0,
• wherein the degree of substitution of R1—CO— at the C6 position (“C6DSR1-CO”) is less than 0.1, wherein the degree of substitution of R4—CO— at the C6 position (“C6DSR4-CO”) is in the range of from about 0.1 to about 1.0,
• wherein the degree of substitution of hydroxyl is in the range of from about 0 to about 2.6,
• wherein R1 is (C6-20)aryl, wherein the aryl is unsubstituted or substituted by 1 to 6 R2 groups,
• wherein R2 is chosen from (C1-6)alkyl, halo(C1-6)alkyl, (C1-6)alkoxy, halo(Ci-6)alkoxy, halo, (C3-7)cycloalkyl, (C6-10)aryl, or nitro,
• wherein R4 is chosen from (C1-20)alkyl;
• halo(C1-5)alkyl;
• (C2-20)alkenyl, or (C3-7)cycloalkyl,
• wherein the film is a uniaxially, biaxially, or 45 degree stretched film.