Synthesis and SANS characterization of poly(vinyl methyl ether)-block-polystyrene

A solid technique to synthesize genuine diblock copolymers of poly(vinyl methyl ether) (PVME) and polystyrene (PS) for the phase behavior study was developed by the coupling reaction between end-chlorinated PVME and living PS anions. The phase behavior of the block copolymer with deuterium-labeled PS (PVME-b-DPS) was investigated by the small-angle neutron scattering (SANS) technique. The existence of a single broad peak in the SANS profile strongly suggested the formation of PVME-b-DPS block copolymer. Although the block copolymer was totally in the disordered state within the temperature range between 34 and 206°C, an increase in the scattering intensity with temperature implying an increase in the amplitude of thermal concentration fluctuation was clearly observed, as expected from the LCST-type phase behavior of PVME/PS blends.