Dynamic mechanical properties of rubberlike materials

Effect of mixing conditions on the rheological and optical properties of chemically modified poly(ethylene terephthalate‐co‐ethylene isophthalate)

“…30 In this figure, the data located upper region demonstrate strong elasticity compared to viscosity. 30,31 Furthermore, the blade rotation speed drastically affected the drawdown force, as shown in Table I. In the case of the samples blended at high rotation speeds, stretching could not be carried out at a draw ratio of 20 because the extruded strand exhibited brittle rupture due to high elongational stress.…”

Multi-focus design of underwater noise control linings based on finite element analysis

“…Formulation of the finite element follows this discussion. (iii) The mass, stiffness and the damping matrices are formed by discretizing the weak formulation of the system differential equations of motion while taking into account the proper material properties [12][13][14] and their frequency dependence.…”

“…Though Easwaran and Munjal [10] have shown the linings to be very effective with respect to the echo reduction, the other aspect, that of transmission reduction, has not been taken care of. For use in such linings, certain class of materials (some special type of viscoelastic materials) have been developed [12][13][14] and are being used for the vibration as well as sound absorption. Their properties have also been studied and improved extensively to fit the exact requirements of these linings.…”

A simple calculation of dielectric loss from dielectric dispersion for polar polymers

“…The cut-off approximation [5,6,7] assuming the integrands in (la), (lb) to vanish for (tJr> 1 and to reduce to their numerators…”

“…Data obtained at frequen cies from 102 to 108 cycles per second for Butvar and for a copol ymer of styrene and methyl methacrylate are a nalyzed and it is fou nd that obse rved and calculated values of t he dielectric losses agree wi thi n 10 per cent or better .Equations r elating the real and the imaginary parts of the dielectric constant have been given , but are not in general use b ecause the equations involved are cumbersome [1 , 2, 3).1 ",;Yorker s mter ested in the mechanical behavior of high polymers h ave shown ho v the real and th e imaginary part of th e modulus of rigidity are r elated through a distribu tion function [4] and how this function can b e obtained by anapproximation m ethod from the r eal par t of th e modulu [5,6] and from both r eal and imaginary parts [7]. I t will be shown how the dielectric loss can b e calculated from dielectric con tant data by an analogous approximation m ethod.…”