6533b85cfe1ef96bd12bd2d5

RESEARCH PRODUCT

Rapid small-angle and wide-angle x-ray studies of crystallization behavior in polymers

subject

description

Small-angle and wide-angle x-ray scattering measurements, using a position-sensitive detector, were made during melt-crystallization of linear polyethylenes and PEO–PS–PEO triblock copolymer. The scattering measurements indicated that the triblock copolymer grew by the enlargement of regions in which lamellae are regularly stacked. During primary crystallization at higher temperatures similar behavior is observed in two linear polyethylenes. At lower temperatures, changes in the shape of small-angle scattering curves during the primary stage of crystallization indicate that amorphous gaps within the lamellar stacking become filled in. During secondary crystallization at higher temperatures new crystallites appear to grow between those formed in the primary stage. Concurrent decrease of the overall scattered intensity leads to the conclusion that secondary crystallization has two components: crystallization of new lamellae behind the spherulite growth front and the thickening of existing lamellae.