Chain orientation resulting from the crystallization under strain of poly(ϵ‐caprolactone) in miscible blends with poly(styrene‐co‐maleic anhydride)

Abstract

AbstractAmorphous miscible blends of poly(ϵ‐caprolactone) (PCL) with a random copolymer of styrene–maleic anhydride (SMA) were stretched at room temperature and the crystallization of PCL was allowed to develop under strain. The crystallization of PCL, from oriented amorphous chains, leads to macroscopic crystalline chain orientation. Using infrared dichroism and wide‐angle X‐ray scattering techniques, it was found that the resultant crystalline orientation of PCL is always parallel to the strain direction, regardless of the experimental conditions, which is in contrast with the PCL/poly(vinyl chloride) blend, where both parallel and perpendicular chain orientations can be induced. Furthermore, the degree of crystalline orientation of PCL is influenced by the initial stretching‐induced amorphous chain orientation of the system. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1683–1690, 2001