EFFECT OF ADDED HOMOPOLYMER ON THE MICROPHASE SEPARATION TRANSITION-TEMPERATURE OF BLOCK-COPOLYMER

The change in the microphase separation transition temperature (T-mst) of a diblock copolymer (AB), induced by the addition of homopolymer ( HA), is theoretically studied. The calculations based on the modified Meier's theory show that T-mst is dependent on both the volume fractio n of added homopolymer and the molecular volume ratio of HA to AB, whi ch is the same as the previous theoretical results and qualitatively i n agreement with the experimental results. This theory also predicts t hat the molecular weight ratio at the crossover of T-mst from elevatio n to depression is affected by the molecular weight of AB.