ИСТИНА

Polymer networks are named hypercrosslinked when the total number of crosslinks is comparable with the total number of monomer units within. Such networks are capable to swell in any solvents, whether good or poor, and absorb almost any substances. In particular, hypercrosslinked polystyrene networks are routinely used for commercial, scientific and medical applications. To obtain such network, crosslinking is conducted rapidly in the whole volume of swollen macromolecules, quenching swollen conformation and preventing it from relaxation. In a dry state these networks bear significant inner stress, relieving which they absorb any liquid or gas. This phenomenological explanation [1] requires to be supported by theoretical studies and computer simulations. In this work, firstly the fully atomistic simulation of intermolecular crosslinking of polystyrene with chloromethylene substituted monomer units was performed using ReaxFF force field [2] which was modified by us in appropriate way. Nowadays ReaxFF is the only force field which allows for the continuous appearance and breaking of chemical bonds and enables the simulation of large reactive systems on atomistic level. The "synthesized" networks (Fig. 1) were investigated by calculation of the microscopic (apparent specific inner surface area, total pore volume and pore size distribution) and macroscopic (polymer density, volumetric thermal expansion coefficient) properties at different degree of crosslinking. Results were compared with real experiment dates. Computational resources were provided by Supercomputing Center of Moscow State University [3]. The reported study was funded by RFBR according to the research project No. 14-03-00073. References 1. Davankov V. A., Tsyurupa M. P. // React. Funct. Polym. 2006. V. 66. P. 181. 2. van Duin A. C. T., Dasgupta S., Lorant F., Goddard III W. A. // J. Phys. Chem. A. 2001. V. 105. P. 9396. 3. Sadovnichy V., Tikhonravov A., Voevodin Vl., Opanasenko V., in Contemporary High Performance Computing: From Petascale toward Exascale, ed. J. S. Vetter. Boca Raton: CRC Press, 2013.