Аннотация:A correlation was established between, on the one hand, the values of the molecular weight of UHMWPE synthesized using postmetallocene bis-phenoxyimine catalysts and the bulk density of synthesized nascent reactor powders of UHMWPE, and, on the other hand, the values of the elastic modulus, breaking strength and breaking elongation of oriented tapes obtained from reactor powders of UHMWPE by the method of solid-state processing below the melting temperature of the polymer without the use of solvents. It has been established that the application of UHMWPE reactor powders with a bulk density of no higher than 0.09 g/cm3 and, at the same time, a polymer molecular weight of not less than 4.5 × 106 g/mol allows one to obtain on their basis by a solid-state method, simultaneously, high-strength (breaking strength up to 3.6 GPa) and high-modulus (modulus of elasticity up to 150 GPa) materials, that is, having the maximum value of the deformation energy to break, which is important for practical applications. Reactor powders of UHMWPE with optimal for solid-state processing values of MM and bulk density, at the level of structural subunits of the nanometer size range had a morphology of the “stack of lamellas” type.
