Yasushi Ichikawa

Strain-induced crystal modification in poly(tetramethylene succinate)

Abstract A new crystal modification induced by strain was found in uniaxially oriented fibres of poly(tetramethylene succinate). This new modification (β form) had a planar zigzag conformation of T10 (all trans) and a fibre identity period of 11.90 A, while the conventional α form had a T7GTḠ conformation and fibre identity period of 10.90 A. The solid-state crystal transition between α and β forms was reversible with respect to the successive application and release of strain.

1,6,11,16-Tetraoxacycloeicosane-2,5,12,15-tetraone.

The 20-membered ring of the title compound, C 16 H 24 O 8 , adopts an approximately flat rectangular structure with three-and seven-bond sides and lies across a crystallographic center of inversion. The corners of the ring occur at both ends of one of the planar ester segments. All of the carbonyl O atoms are involved in intermolecular C-H···O hydrogen bonds.