SPIN CONTRAST MEASUREMENT OF INTERFERENCE IN POLYMER MIXTURES

The intra and intermolecular structure functions of polymers in soluti on have been measured by small angle scattering using spin contrast va riation by dynamic nuclear polarization. For a block-copolymer (PSH-PS D) in 50% deuterated ortho-terphenyl, the results agree with earlier t heories for polymers in a good solvent. In a mixture of two polymers, polydichlorophosphazene and PSH in partially deuterated toluene, the c onformation of each polymer and their interference could be obtained s eparately from measurements at positive, negative and zero nuclear pol arization respectively, using a single sample. Both polymers have incr eased radii of gyration and the interference term is negative.