Polycarbonate-based block copolymers and devices

A block copolymer consisting essentially of at least one crystalline of semi-crystalline rigid "A" block, and at least one flexible, amorphous "B" block,

• said "A" block formed from at least one type of recurring monomeric unit of the following General Structures I and II:
• ##STR15## wherein:
• ##STR16## --O-- or a combination thereof, where Z is selected such that there are no adjacent heteroatoms;
• n and m are the same or different at each occurrence and are integers from about 1 to 8;
• R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are the same or different at each occurrence and are hydrogen, alkoxyaryl, aryloxyaryl, arylalkyl, alkylarylalkyl, arylalkylaryl, alkylaryl, arylcarbonylalkyl, aryloxyalkyl, alkyl, aryl, alkylcarbonylalkyl, alkoxyalkyl, or aryl or alkyl substituted with one or more alkyl, aryl, alkoxy, aryloxy, dialkylamino, diarylamino, or alkylarylamino substituents;
• R.sub.5 and R.sub.6 are the same or different and are R.sub.1, R.sub.2, R.sub.3, R.sub.4, dialkylamino, diarylamino, alkylarylamino, alkoxy, aryloxy, alkanoyl, or arylcarbonyl, or any two of R.sub.5 and R.sub.6 substituents together may form an alkylene chain completing a 3, 4, 5, 6, 7, 8 or 9 membered alicyclic, fused, spiro, bicyclic or tricyclic ring system or a combination thereof, which system may optionally include one or more non-adjacent carbonyl, oxa, alkylaza or arylaza groups;
• and
• said "B" block formed from recurring units derived from monomers selected from the group formed from lactones, carbonates, anhydrides, hydroxycarboxylic acids, lactides, dioxepanones other than carbonates, dioxanones other than carbonates, orthoesters, and epoxides/CO.sub.2, with the proviso that at least one of R.sub.1 to R.sub.6 is other than hydrogen.