Behavior of Highly-Filled Rubber Vulcanizates

Abstract

Examination of the stress-strain curves of vuloanizates containing up to 60 per cent by volume of mineral filler of particle size greater than 1 µ has led to the discovery of a plateau at which the elongation increases several hundred-fold at constant stress. This has been demonstrated for a number of fillers with several rubbers, natural and synthetic. The effect of filler content, particle size, and degree of cure on the stress at which the plateau occurs, and its length, have been investigated. An explanation is suggested and the significance of the observations for the experimental verification of equations relating modulus to filler content is pointed out. The volume changes accompanying the elongation of these vulcanizates have also been investigated at varying filler contents, particle sizes, and degrees of cure, and shown to correlate with the stress-strain curves. The possible bearing of these results on the nature of the rubber-filler bonds, and hence on the reinforcing action of fillers, is briefly discussed.

Mechanical behavior and dilatation of particulate‐filled thermosets in the rubbery state

“…It was found that the second derivatives of the dilatation-strain curves (AVIVo vs. c) could be represented by the Gaussian function. A typical dilatation-strain curve represented by the second integral of the Gaussian function is shown in Equation (8) implies that a plot of (AV/Vo)I(sVfmax) vs. Table I1 along with moduli values. The shifted points lie very close to the theoretical line except for the low strain part of the 1Wo and 20% filled composites.…”

Study on volume change and scanning electron microscope observation of carbon black‐filled natural rubber upon stretching

“…[2] Since then, researchers have conducted systematic studies on the volume variation of vulcanizates and plastics during stretching. [3][4][5][6][7] The volume change of vulcanizates used to be measured mainly by dilatometer [8][9][10][11] and hydrostatic weighing methods. [12][13][14] The effects of rubber type, fillers, testing methods, and testing conditions on volume change have been investigated.…”

Silica masterbatches produced with liquid phase mixing Part IV. Volume variation and SEM observations upon stretching

“…A great deal of research has been done on the volume change of vulcanizates and plastics during the process of stretching. [4][5][6][7][8] Two major measuring methods, dilatometry [9][10][11][12] and hydrostatic weighing, [13][14][15] have been used. Many different kinds of vulcanizate and filler systems have been tested.…”