Epitaxial crystallization of poly(butylene adipate) on highly oriented isotactic polypropylene thin film

The crystallization behaviors of PBA on highly oriented iPP substrate both from solution and isotropic melt were studied by means of optical microscopy, AFM, X-ray and electron diffractions. The results clearly indicate the occurrence of heteroepitaxy of PBA on the iPP substrate in its β-form with both molecular chains ±50° apart from. This is based on the existence of perfect matching between the interchain distance of β-PBA along [100] direction and the distance of the out-sticking methyl side group arrays along the [101] direction of the (010) iPP plane. Electron diffraction pattern further confirms that the (010) lattice plane of the β-PBA is in contact with the iPP substrate.