Influence of cross-linking rate on the structure of hypercrosslinked networks: Multiscale computer simulation

- The hypercrosslinked polystyrene (HCP) was studied by multi-scale modeling.
- Cross-linking of HCP was simulated at different reaction rates.
- Cross-linking rate affects porosity and macroscopic properties of HCP networks.
- Fast cross-linked HCP have narrow pore size distribution and high specific surface.
- The lower is the cross-linking rate, the smaller is the specific surface.

A multi-scale molecular dynamics simulation was implied to study the formation of hypercrosslinked polystyrene networks at different rates of cross-linking. The rate of cross-linking reaction was controlled by wide-range variation of the probability of chemical bonding between the particles within the reaction distance on individual step of the simulation. The cross-linking was performed in the framework of the coarse-grained model, with the force fields derived from atomistic simulations. The macroscopic properties of network were studied using the atomistic samples restored from the coarse-grained configurations by a reverse mapping procedure. It was shown that the rate of cross-linking influences the structure of “synthesized” hypercrosslinked networks: Slowly cross-linked polymer networks have smaller total specific surface, lower average density, larger pores than those cross-linked at high rate.

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