Mass loss of P(BHET-EOP/TC, 80 : 20) discs after incubation in 0.1 M PBS at 37°C. Molecular weights of the sample tested are: P(BHET-EOP/TC, 80 : 20), Mw = 12 500; P(BHET-EOP/MOP/TC, 60 : 20 : 20), Mw = 9350; P(BHET-EOP/MOP/TC, 40 : 40 : 20), Mw = 7830. No Mw data were available for P(BHET-EOP/NaOP/TC, 60 : 20 : 20) and P(BHET-EOP/NaOP/TC, 40 : 40 : 20).