Effect of Protein-like Copolymers Composition on the Phase Separation Dynamics of a Polymer Blend: A Monte Carlo Simulation

We use kinetic Monte Carlo simulation based on the bond fluctuation model to investigate the dynamics of phase separation in immiscible 80/20 A/B binary polymer blends, comprising 80% and 20% of A and B components, respectively, in the presence of ≈4.92% 30-mer protein-like copolymer (PLC) made of C and D segments. The molecular interactions are chosen such that there is an attraction between A and C and between B and D segments and no interaction between like segments; all other interaction energies have been chosen to be repulsive. The PLC migration to and presence at the A/B interface effectively slow down the process of phase separation in binary blends, thereby minimizing the unfavorable A/B contacts and reducing the A/B interfacial tension. The ability of PLCs to effectively retard the process of phase separation depends sensitively on the PLC composition. PLCs with 0.3 ≤ <i>x</i>_C ≤ 0.5, where <i>x</i>_C is the mole fraction of C, are most effective in compatibilizing the 80/20 A/B binary blend. The growth of phase-separated domains follows a dynamical scaling law for both the binary and ternary blends compatibilized by PLCs in the late stage of phase separation with universal scaling functions that are nearly independent of PLC composition