STRUCTURE DEVELOPMENT BY REACTION-INDUCED PHASE-SEPARATION IN POLYMERMIXTURES - 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 procee ds via the spinodal decomposition (SD) to yield the regularly phase-se parated morphology. However, the SD is expected to take place under su ccessive increases in quench depth. To evaluate the demixing process u nder the non-isoquench depth condition, we carried out computer simula tions 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 t wo-phase structure as in the case of the SD under isoquench, the struc ture 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 developme nt in the reaction-induced SD.