Abstract
A new molecular mechanism for the healing phenomenon in semicrystalline linear polycondensates (healing resulting from chemical reactions between macromolecules located in the interfacial surface) is demonstrated. Strips of commercial poly(ethylene terephthalate) are annealed at 258°C in order to avoid melt sticking. Two such strips are partially overlapped, pressed, and heated in a vacuum at 240°C for 10, 20, 30, and 100 h. By measuring the stress at break outside the contact area and the debonding shear stress the critical overlapping length is computed. It is concluded that transreaction contributes more than solid‐state post‐condensation to chemical healing.