Issue 31

E.M. Nurullaev et alii, Frattura ed Integrità Strutturale, 31 (2015) 120-126; DOI: 10.3221/IGF-ESIS.31.09 125 as well as the structural glass-transition temperature of the polymer binder. In this case, the decrease in ultimate tensile stress ( σ b ( MPa )), related to ( α b ( mm )) by the formula:    1 2 1 2 1 b b b b C C          with previously adopted notations applied to the Eq. (1), occurs to a lesser degree. This can probably explain the corresponding increase in the values of W ( J ), at increasing ε b (%). The theoretically derived dependence (5) of the mechanical fracture energy of a 3D cross-linked filled elastomer from the basic structural parameters of the composite can be recommended for solving direct and indirect problems when developing new PCMs as polymer composites for various purposes with the desired combination of performance characteristics [7]. In doing so, it is expedient to use computer programs, including mathematical optimization techniques [15, 16], which will help to reduce the development time and cost of raw materials, for example, when developing advanced PCMs. Figure 1 : Experimental dependence     0 3 % [ / ] b eff f mol cm    for various polymeric binders based on: : Poly(butyl formal sulfide), : Poly(ester urethane) hydroxide, : Polydiene epoxy urethane, : Carboxyl-terminated polybutadiene, : Polyisoprene butyl; The data are given for standard conditions: Т= 293 К and   =1.4·10 -3 c -1 . Figure 2 : Dependence of the mechanical fracture energy on ruptural deformation of a PCM at temperatures: 1 – 223 K ; 2 – 273 K; 3 – 323 K. : two-fraction composition; : three-fraction composition; : four-fraction composition;