Alternating Crystalline‐Amorphous Layers in Hybrid Block Copolymers of Linear Poly(ethylene glycol) and Dendritic Poly(benzyl ether)

Abstract

Abstract Summary: In the present work, we have studied the crystalline morphology of hybrid di‐ and triblock copolymers consisting of linear poly(ethylene glycol) (PEG) and Fréchet‐type monodendrons of poly(benzyl ether). The linear blocks can crystallize to form spherulites under supercooling condition. Using atomic force microscopy and small‐angle X‐ray scattering method we found alternating crystalline and amorphous layers. The crystalline layers are formed by the PEG block, while the amorphous layers contain the miscible mixture of PEG and the monodendrons. Our analysis shows that the long period, d , of the layers scales as d ∝ M where $M_{\rm D}$ is the molecular weight of the monodendrons. As the radius of gyration of the monodendrons R g , also scales as R g ∝ M (B. M. Tande, et al. Macromolecules 2001 , 34 , 8580), we obtain d ∝ R g , implying a linear increase of the long period with the radius of gyration of the monodendrons. Model describing the crystalline morphology of the semicrystalline hybrid block copolymers. magnified image Model describing the crystalline morphology of the semicrystalline hybrid block copolymers.