BAB Type Research Articles

Microdomain structure of poly(styrene‐4‐vinylpyridine) diblock copolymers

AbstractA series of AB and BAB type poly(styrene‐4‐vinylpyridine) diblock copolymers with a sharp distribution of molecular weights were synthesized to study relationships between the molecular weight and domain size of lamellar and spherical microdomains. The domain sizes of diblock copolymer specimens cast from chloroform or 1,1,2‐trichloroethane were estimated from transmission electron micrographs. As a result, the lameller domain spacings, predicted from Halfand's theory, agree well with the experimental results. The radius of spherical domains is far below the theoretical values predicted from Helfand's theory, though.

Block Polymers Derived from Poly(ethylene Oxide) and Hydroxy-Terminated Polybutadiene

Abstract Block polymers of AB, BAB, and ABA type, derived from preformed poly(ethylene oxide) (PEO) of different molecular weight and hydroxy-terminated polybutadiene (HTPB) were prepared. Poly(ethylene oxide-b-butadiene) and poly(butadiene-b-ethylene oxide-b-butadiene) were prepared by reaction of PEO, which was previously endcapped with TDI, with HTPB at a 1:1 or 1:2 reactants molar ratio. Poly(ethylene-oxide-b-butadiene-b-ethylene oxide) were prepared by reaction of isocyanate-endcapped HTPB with PEO at a molar ratio of reactants of 2:1. High reaction yields were obtained. Correlation between tensile properties and water absorption with block polymer composition was found.