Properties of polyurethane elastomers

A. T. Chen, and co-workers, "Comparison of the Dynamic Properties of Polyurethane Elastomers Based on Low Unsaturation Polyoxypropylene Glycols and Poly(tetramethylene oxide) Glycols," Polyurethanes World Congress 1993, Vancouver, B.C., Canada, Oct. 10—13,1993. 

Table 11. Properties of Polyurethane/Elastomer Block Copolymers...

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...

A. T. Chen, and co-workers, "Comparison of the Dynamic Properties of Polyurethane Elastomers Based on Low Unsaturation Polyoxypropylene... 

Table 4.5. Physical properties of polyurethane elastomers prepared from HTPB and 2,4-toluene diisocyanate (TDI) 205)...

Nasar, A. S., Jikei, M., Kakimoto, M.aki. (2003). Synthesis and properties of polyurethane elastomers crosslinked with amine-terminated AB2-type hyperbranched polyamides, Eur. Pnlvm. 1. 39,1201-1208. 

The book reviews aspects from the up-to-date literature focused on these topics including our research. In addition the book records selected results from an international NATO project collaboration between The Department of Engineering Science, University of Oxford and our Romanian laboratory at the Institute of Macro-molecular Chemistry Petru Poni , Iasi. This has made possible an unusually comprehensive study of the structure and important physical properties of polyurethane elastomers—a class of polymer of such great industrial importance. 

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. 

STRUCTURE EFFECTS OF AROMATIC AMINE EXTENDERS ON THE PROPERTIES OF POLYURETHANE ELASTOMERS ... 

The contribution which the different types of polar groups make to the properties of polyurethane elastomers depends in part upon their ability to enter into strong hydrogen-bonded associations. The substituted urea linkage, formed by the reaction of an isocyanate with an amine, is regarded as exceptional in its contribution to the physical properties, and it is therefore a preferred component in many bulk elastomers where the structural irregularity introduced by the use of a non-symmetrical diisocyanate or polyol is compensated by the strong urea interactions. 

The physical properties of polyurethane elastomers using these diamine curing agents/chain extenders are given in Tables 5.7(c)-(m). 

SYNTHESIS AND PROPERTIES OF POLYURETHANE ELASTOMERS BASED ON AROMATIC l/f/ S(7S ALIPHATIC... 

COMPARISON OF PHYSICAL PROPERTIES OF POLYURETHANE ELASTOMERS WITH COMMON RUBBERS AND PLASTICS... 

Low temperature Low temperature environments affect the properties of polyurethane elastomers, but no degradation occurs and the effect is completely reversible. An increase in Young s modulus occurs below with a corresponding increase in hardness, tensile strength, tear strength and torsional stiffness, and a decrease in resilience. 

So far, our discussion of the mechanical properties of polyurethane elastomers was predicated on the implicit assumption that the morphology of the microphase-separated material is at equilibrium or close to equilibrium. It is, therefore, important to understand the limitations of this assumption and to see how the preparation history might influence the properties. 

In this chapter, we reviewed some of the recent developments in modeling and predicting the mechanical properties of polyurethane elastomers as a function of their formulation. Based on the knowledge of the formulation and processing history, one can roughly predict the degree of the microphase separation between the hard and soft phases. That, in turn, enables the construction of constitutive micromechanical models for the calculation of elastic, viscoelastic, and nonlinear tensile and compressive properties. 

Table 3. Composition and some properties of polyurethane elastomers based on asymmetric dimethylhydrazine...

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