STRUCTURE DEVELOPMENT BY REACTION-INDUCED PHASE-SEPARATION IN POLYMER MIXTURES - COMPUTER-SIMULATION OF THE SPINODAL DECOMPOSITION UNDER THE NON-ISOQUENCH DEPTH

It has been shown that, in various thermoset/thermoplastic and monomer/polymer mixtures, demixing is induced by polymerization and it proceeds via the spinodal decomposition (SD) to yield the regularly phase-separated morphology. However, the SD is expected to take place under successive increases in quench depth. To evaluate the demixing process under the non-isoquench depth condition, we carried out computer simulations of the time dependent concentration fluctuations using the Cahn-Hilliard non-linear diffusion equation. The simulations revealed that the SD under successive increases in quench depth yields the regular two-phase structure as in the case of the SD under isoquench, the structure coarsening is suppressed by the increase in quench depth, and the final morphology is highly dependent on the quench rate. The results adequately describe the characteristic features of structure development in the reaction-induced SD.