On the microphase separation kinetics of symmetric diblock copolymers

Time-resolved small-angle x-ray scattering studies were performed on symmetric diblock copolymers of polystyrene and poly(methyl methacrylate), P(S-b-MMA). Freeze-dried powders of P(S-b-MMA) having a molecular weight of 8.4×10⁴ were rapidly heated to temperatures above the glass transition temperature to initiate the microphase separation. The microphase separation process was found to consist of a rapid, local microphase separation followed by a long-term coarsening process. The period characterizing the lamellar microphase separated structure was found to increase initiallv and then saturate at longer times. These results are discussed in light of recent theoretical developments.In celebration of his 65th birthday, this article is dedicated to Prof. E. W. Fischer whose methodic and thorough approach to research has been and continues to be a model for us to follow. Es freut mich, daß ich mit Herrn Fischer gearbeitet habe. Ich habe vieles von ihm gelernt. Ich hoffe, daß auch ich so fleißig sein werde, wenn ich so jung bin wie er.