THE CRYSTALLIZATION OF APERIODIC POLYMER CHAINS Alan Windle, Department of Materials Science and Metallurgy, Pembroke Street, Cambridge, UK CB2 3QZ

Polymers with aperiodic chains have a quite remarkable ability to crystallise. However, there are a number of distinctly different mechanisms which enable a chemically aperiodic chain to contribute to the three dimensional periodicity of a crystal lattice.

The paper will review several different systems as examples of mechanistic types, and in each case explore the diffraction consequences. The systems described will be:polyvinyl alchohol, polyvinyl chloride, branched polyethylene, PET/PEN random copolymers, and thermotropic random copolyesters. The issues addressed will include sequence rejection, defect inclusion, conformational adjectment and sequence matching in the crystalline phases.