Effects of compositional asymmetry in phase behavior of ABA triblock copolymer melts from Monte Carlo simulation.
We simulate ABA triblock copolymer melts using a lattice Monte Carlo method, known as cooperative motion algorithm, probing various degrees of compositional asymmetry. Selected order-disorder transition lines are determined in terms of the segment incompatibility, quantified by product χN , and the triblock asymmetry parameters, α and β. We correlate the results of the simulation with the self-consistent field theory and an experimental study of polyisoprene-polystyrene-polyisoprene triblock melt by Hamersky and coworkers. In particular, we confirm the mean-field prediction that for highly asymmetric triblocks the short A -block is localized in the middle of the B -domain due to an entropic advantage. This results in the middle block relaxation and is consistent with the experimental data indicating that as the relatively short A -blocks are grown into AB diblock, from the B -block side, the order-disorder transition temperature is considerably depressed.
Faculty of Physics, A. Mickiewicz University, ul. Umultowska 85, 61-614, Poznan, Poland.
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D000465:Algorithms; D003198:Computer Simulation; D045782:Hemiterpenes / Q000737:chemistry*; D007840:Latex / Q000737:chemistry*; D009010:Monte Carlo Method; D044367:Phase Transition; D011137:Polystyrenes / Q000737:chemistry*; D013696:Temperature
D045782:Hemiterpenes; D007840:Latex; D011137:Polystyrenes; C455100:1,4-polyisoprene