Interrelationship between ultimate mechanical properties of variously structured polyurethanes and poly(urethane urea)s and stretching rate thereof

Abstract

The ultimate mechanical properties of polyurethane determine their possible applications under various conditions of mechanical action. The mechanical properties of nine polyurethane and polyurethane urea samples were investigated in a range of stretching rates 0.56÷0.002 s −1 . A part of experiments was performed at several temperature values under conditions of stepwise variable stretching rates. The interrelationship between rate dependence of strength-strain properties of polyurethane compositions and the structure thereof was ascertained. The influence of molecular structure's variations, of physical network density and of segmented polyurethane and polyurethane urea morphology on said interrelationship was examined on samples subjected to large strain values. The structure of some samples was radically distorted by plasticizers oppositely influencing micro-phase segregation of soft and hard segments. Multiple kinds of dependency (direct, inverse, moderate and strong) of elastomers' strength versus stretching rate were demonstrated. Produced data and ascertained regularities are useful to perceive reasons for diversity of mechanical behavior of polyurethane materials and to control properties thereof.

New diurethane plasticizers for polyurethane thermoplastics and perspective functional composites

“…FTIR spectra were recorded using a Vertex 80v spectrometer, with spectral resolution of 1 cm −1 . Samples of TPU films with thicknesses of 10–15 μm were prepared without volatile solvents, according to methods published elsewhere . FTIR spectra of the pure diurethanes were recorded under ambient conditions by preparing the samples with KBr pellets.…”

“…Experiments were performed at two ratios of NCO/OH = 0.95 (TPUW‐1) and 0.98 (TPUW‐2). The reaction mass was produced under the same conditions described elsewhere . The polyurethane binder contained 30 wt % plasticizer (BTU).…”

Stress–Strain Dependence of Segmented Polyurethanes and Polyurethane Ureas

“…Both of the synthesis stages were performed according to our methods given elsewhere. [28,32] Ratios of the components in the syntheses are listed in Tables 1-4.…”

“…The glass transition temperatures of the soft phase, T s g , in the investigated samples were in a range significantly lower than the testing temperature, 25 C. T s g was below ¡60 C for the samples based on the oligodienediol; [32] it was below ¡50 C for the samples based on PTMO. [28] These glass transition temperatures were determined for the polyurethanes and polyurethane ureas based on the oligoesterdiol OMA-2100 with the highest content of hard segments. They were ¡35 C for BTL-5, and ¡28 C for BPL-28.…”

Development and Evaluation of Anti-corrosion and Anti-bacterial Polymer Coatings for Circulation Coins

“…Polyurethane (PUR or PU) is a polymer composed of organic units jointed by urethane links. It is produced by the polyaddition reaction of either a diisocyanate or a polymeric isocyanate with a polyol in the presence of suitable catalysts and additives [76]. Polyurethane has various applications because its properties can be modified by catalysts, auxiliary compound, and raw material selection, but there are two limiting factors that restrict its applications: (1) instability at temperature above 90℃; and 2flammability [79].…”