Novel Polyglycolic Acid and Preparation Method Thereof by Polycondensation

A polyglycolic acid comprising first repeating units of formula (I) and second repeating units of E-R2—F, wherein formula (I) is

• wherein:
• R1 and R2 are each an aliphatic or aromatic group;
• G1, G2 . . . Gi is
• respectively;
• i is greater than or equal to 3;
• X1, X2 . . . Xi, E and F are each —NH—C(O)—, —O—, —NH— or —C(O)— except:
• (a) when each of X1, X2 . . . Xi is —O— or —NH—, E and F are each —NH—C(O)— or —C(O)— and
• (b) when each of X1, X2 . . . Xi is —NH—C(O)— or —C(O)—, E and F are each —O— or —NH—.