Size dependence of crystallization within spherical microdomain structures

We have investigated the size dependence of crystallization within spherical microdomains formed in various poly(ε-caprolactone)-block-polybutadiene diblock copolymers (PCL-b-PB). The crystallinity (χ) and melting temperature (Tm) of the PCL block are considerably lower than those of PCL homopolymer, and χ decreases steadily and Tm decreases only slightly with decreasing radius of PCL spheres (R) for a series of PCL-b-PB with a same molecular weight (Mn). When PCL-b-PB is compared with the similar R but different Mn, χ is significantly different, suggesting that the sphere size is not the unique factor to control crystallization within spherical microdomains.