Cross-linkable thermoplastics, and processes of making and using same

A cross-linkable thermoplastic having the following structure:

• wherein
• a) each X is independently O, CH2, or C═O;
• b) at least one of R1, R2, R3, and R4 is phenylethynyl, with the remainder of R1, R2, R3, and R4 each independently being H or phenylethynyl;
• c) each Y is independently selected from one of the following moieties:
• where each L is independently a bivalent linker selected from the one of following moieties:
• O, C═O, SO2, C(CF3)2, C(CF3)Ph, and —O—(pC6H4)—C(CF3)2—(pC6H4)—O—;
• d) each Ar is independently:
• and
• e) each a is from 0.01 to 1;
• and
• f) n is an integer from about 3 to about 200.