Summary: High‐quality synthetic polymer extended‐chain single crystals with c‐axis thickness exceeding 100 µm are obtained in a polyethylene terephthalate/polycarbonate (PET/PC) blend rapidly. Some crystals comprise of PET, while others are made up by the copolymers with PET and PC blocks. The fast growth of large crystals is attributed to the mechanisms including transesterification, segment nucleation, and chain‐sliding diffusion, which is a self‐assembling process induced by chemical reactions in multiphase polymer system at high pressure. Similar to the role of enzyme in biosystem, the PC plays as a macromolecular catalyst. This process provides a new direction to grow large polymer single crystals and suggests that self‐assembly under high pressure is a promising method to create materials with new structures and properties.
SEI for a wedge‐shaped extended‐chain single crystal grown in a PET/PC blend at 200 MPa, 623 K for 6 h.
