Mechanical properties of polyurethane

Table 1. Dependence of the kinetic parameters of the reaction, the structural parameters of the network and the physico-mechanical properties of polyurethane elastomers on the molar fraction of OH groups in the monofunctional reagent21...

On the other hand, San Miguel and Duran (Ref 125) showed that the mechanical properties of polyurethane solid proplnt were degraded significantly by gamma irradiation dosages greater than 106 R. The tests used to determine the effects were by swelling, torsion, uniaxial tension and multiaxial tension... 

Table II. Thermal and Mechanical Properties of Polyurethanes Based on PTHF629 Diols, Monoglucosides, and Bisglucosides...

J Nakano, Y Izuta, T Orita, H Hatakeyama, K Kobashigawa, K Teruya, S Hirose. Thermal and mechanical properties of polyurethanes derived from fractionated kraft lignin. Sen-I Gakkaishi 53 416 22, 1997. 

The dynamic mechanical relaxations in the high temperature region are very weak and the glass transition was indistinguishable from the melting point (Fig. 4). However, the mechanical properties of polyurethanes with chemically crosslinked hard segments were quite different from uncrosslinked polyurethanes. In the linear adhesives (73-14 and 73-15), the rubbery plateau ends at the melting point of the... 

A novel nonisocyanate polyurethane binder for monolithic flooring and industrial paint compositions was produced on an industrial scale [34], The two component binders have unique properties that combine the best mechanical properties of polyurethane and the chemical resistance of epoxy binders [35,36], The polyurethane binders do not present health hazards because they do not consist of isocyanate... 

S.4.4 Physical and mechanical properties of polyurethane networks and surfactant additives. The cohesion and adhesion properties of the cured polymers were investigated to elucidate the influence of KEP-2 on the physicsd and mechanical properties of polyurethane networks based on PPG in the presence of individual ohgomers. 

TABLE 3.21 Physical and Mechanical Properties of Polyurethane Networks Based on Different Oligoglycols (ODA, PTMG), Trimethylolpropane, and TDI at (343 1) K... 

TABLE 3.29 Physical and Mechanical Properties of Polyurethane Nets Based on ODA and PPG Incompatible Oligoether Mixtures, Trimethylolpropane, and Toluylene Diisocyanate at 343 1 K... 

Physical and mechanical properties of polyurethane networks based on another incompatible oligoglycol pair, ODA and PTMG at their equimolar ratio, are presented in Table 3.30. As the table shows, polyurethane specimens were synthesized with various KEP-2 concentrations in the oligomer mixture, including those for which extrema were observed for the thermodynamic functions. This concentration is... 

Badri, K. H., Bin Othman, Z., and Razali, I. M. Mechanical properties of polyurethane composites from oil pahn resources. Iranian Polymer Journal, 14, 5 441 48 (2005). 

The presence of ionic groups in polyurethanes is known to drastically change the mechanical properties of polyurethanes (18), but the remarkable effects on adhesion have not been reported previously. The presence of such ionic bonds is consistent with the fact that adhesion in these systems is markedly reduced by soaking a few days in water, which would solvate the ionic clusters (18) and reduce their effectiveness in promoting adhesion. It is noteworthy that strong adhesive bonds reform on drying (19). ... 

C. Prisacariu, C.P. Buckley, Influence of the type of chain extender and urethane group content in the mechanical properties of polyurethanes based on 4,4- dibenzyl diisocyanate (2006), pp. 456 - 459. 13th International Conference on Deformation, Yield and Fracture of Polymers, Conf. Proceedings... 

The book covers aspects from the morphology to mechanical aspects focused on the elasticity and inelasticity of amorphous to crystalline polyurethane elastomers, in relation to their sensitivity to chemical and physical structure. In such polymers, resilience of the material is an important attribute. In many applications they are in commercial competition with other, relatively soft, elastomeric materials. The choice of material for any given application then hinges on a spectrum of key properties offered by relatively soft polymers—stiffness and strain recovery characterizing their elasticity, but also inelastic effects such as hysteresis and stress relaxation. In these respects the mechanical properties of polyurethane elastomers are similar to those of other elastomers. 

Cho JW, Lee SH (2004) Influence of silica on shape memory effect and mechanical properties of polyurethane-silica hybrids. Eur Polym J 40 1343-1348... 

Guo S, Zhang C, Peng H, Wang W, Liu T. Structural characterization, thermal and mechanical properties of polyurethane/CoAl layered double hydroxide nanocomposites prepared via in situ polymerization. Compos Sci Technol February 2011 71 791-6. 

Xiong J, Liu Y, Yang X, Wang X. Thermal and mechanical properties of polyurethane/ montmorillonite nanocomposites based on a novel reactive modifier. Polym Degrad Stab December 2004 86(3) 549-55. 

Saha MC, Kabir MdE, Jeelani S. Enhancement in thermal and mechanical properties of polyurethane foam infused with nanoparticles. Mater Sci Eng A April 2008 479 213-22. 

Heijkants RGJC, Van Calck RV, Van Tienen TG, De Groot JH, Buma P, Pennings AJ, et al. Uncatalyzed synthesis, thermal and mechanical properties of polyurethanes based on poly(E-caprolactone) and 1,4-butane diisocyanate with uniform hard segment. Biomaterials 2005 26 4219-28. 

J. L. Illinger, N. S. Schneider and F. E. Karasz, "Low Temperature Dynamic Mechanical Properties of Polyurethane-Polyether Block Copolymers", Poly. Eng. Sci. 1, 25 (1972). 

Effect of moisture absorption on the dynamic mechanical properties of polyurethane... 

Zetterlund P, Hirose S, Hatakeyama T, Hatakeyama H, Albertsson A-C (1997) Thermal and Mechanical properties of polyurethanes derived from mono- and disaccharides. Polym Int 42 1-8... 

Hatakeyama H, Nakayachi, Hatakeyama T (2005) Thermal and mechanical properties of polyurethane-based geocomposites derived from lignin and molasses. Comp Part A Appl Sci Manuf 36 698-704... 

An important point is that the percolation threshold, depends on the morphology of the percolating clustei-s, and thus on the incompatibility between the two phases. We postulate that = fgQ, so that once hard phase spheres aggregate into infinite cylinders, percolated hard phase is formed. This assumption is a crucial link that relates thermodynamic information about the hard segment (its cohesive energy density or solubility parameter) to mechanical properties of polyurethanes based on that hard segment. 

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