Lamellar ethylene oxide-butadiene block copolymer films as model systems for confined crystallisation

Semicrystalline poly(ethylene oxide-b-butadiene) diblock copolymers in uniform lamellar films axe discussed as a model system for confined crystallisation. At low supercooling crystn.of the PEO block leads to an increase in the lamellar thickness of both blocks, which is accompanied by a contraction in the lateral direction resulting in cracking of the films. A tentative model is discussed with an integer or half-integer number of folds in the vertically oriented crystalline stems. However, emphasis is also on aspects still not understood.