Segmented polyurethane ureas (SPUUs) were synthesized on the base of oligopropylene oxide (PPO), oligotetramethylene oxide (PTMO), 2,4-toluene diisocyanate, isophorone diisocyanate (IDI), and methylene- o-chloroaniline. Structure of polymer chains with thermodynamically compatible PTMO and PPO soft segments (SS) was identified using data from rheokinetic studies of reactionary mixes with different diisocyanates. The significant swelling value in low-polar solvent toluene and non-elevated softening temperature indicates the formation of loose (defect) structure of the hard phase in compositions, synthesized using IDI. Thermal, thermomechanical, and physicomechanical properties of SPUU with variable compositions of hard segment and SS (blocks) were investigated. An interrelation between structure and properties of block copolymers of new type was estimated. Investigation results showed a significant increase in the strength of polyurethane urea at the equimolar ration between various hard blocks and SS on the base of PPO and PTMO. High strength values were obtained for SPUU in a wide diapason of stretching rates (0.56–0.003 s−1). Structural factors contributing to stability of strength properties of tetrablock-copolymers, namely: stronger inter-chain interaction in the soft phase and a “loose” structure of the hard phase. were revealed. The data relating to elevation of thermostability of these materials were given. New materials can be applied for various conditions of mechanical loading.

Segmented poly(urethaneureas) (SPUUs) modified with low glass transition temperature chemically inert liquids are of interest due to their controllable properties and potential applications under various environmental conditions. Investigation into the influence of plasticizers on the properties of SPUUs based on oligotetramethyleneoxide diol (polytetramethyleneoxide), oligopropyleneoxide diol (polypropyleneoxide), 2,4toluenediisocyanate, Ethacure-300, and methylene-bis-o-chloroaniline was conducted. Partial crystallization of polytetramethyleneoxide segments was identified during cooling of some SPUU samples plasticized by di-(2-ethylhexyl)sebacate (DEHS) and tributyl phosphate. Polypropyleneoxide segments did not crystallize under the same conditions. A low crystallization temperature for the amorphous component of the polymer matrix in SPUU (À100 C to 103 C) was attained at a molecular mass (M n) of soft segments equal to 2000 g mol À1 and a DEHS concentration equal to 40-45%. A relationship between the mechanical properties of plasticized SPUU, microphase segregation, and dilution of the polymer matrix was found. For the first time, the effect of dilution with plasticizer on the strength of elastomers was considered. The plasticization effect on the mechanical properties of SPUU was investigated in the temperature diapason from 50 C to À70 C. The results of these investigations can be used in various technologies including the design of SPUUs with high elastic properties at temperatures as low as À70 C, typical of extreme conditions of the Arctic climate.