Small‐angle neutron scattering studies of chain conformation in semicrystalline hydrogenated polybutadiene

Mixtures of model crystallizable copolymers, hydrogenated polybutadiene (HPB) and deuterated polybutadiene (DPB), were investigated by SANS in the intermediate q range (0.02 ≤ q ≤ 0.18 Å −1 ). Linear and three‐arm‐star polymers were crystallized by quenching and slow cooling at rates differing by 3000‐fold. Care was taken in subtracting the incoherent background scattering. The coherent cross section shows a q −2 dependence which results in a constant Kratky plateau. Absolute SANS intensity is slightly greater than predicted for amorphous chains and is very insensitive to crystallization conditions in these polymers, changing by less than 10%. These observations are interpreted in terms of the gambler's‐ruin model for chain configurations in semicrystalline polymers.