Crystallization of Double Crystalline Diblock Copolymer by Dynamic Monte Carlo Simulation

摘要

We report dynamic Monte Carlo simulation results on the crystallization of double crystalline A-B diblock copolymer, wherein the melting temperature of A-block is higher than B-block. Crystallization of A-block precedes the crystallization of B-block upon cooling from a homogeneous melt. The interaction between A-type and B-type units is modelled as the repulsive interaction to represent their mutual immiscibility. The morphological development is controlled by the interplay between crystallization and microphase separation. With increasing segregation strength, we observe a gradual decrease in crystallinity accompanying with smaller and thinner crystals. During crystallization, A-block crystallizes first and creates confinement for the crystallization of the B-block. Thus, crystallization of B-block slows down, infiuencing the overall crystal morphology. With changing block composition, we observe a non-monotonic trend in the crystallization behaviour (viz., crystallinity, lamellar thickness) of A-block when B-block composition is significantly higher than A-block. This non-monotonic trend is attributed to the dilution effect of the B-block.