Heats of Combustion of Rubber and of Rubber-Sulfur Compounds

Abstract

The work described in this paper is part of a series of investigations at the National Bureau of Standards to determine the properties of purified rubber and of compounds of purified rubber and sulfur. Values of the heat of combustion of rubber have been reported by a number of observers, and values of the heat of combination of rubber and sulfur, determined as the difference in the heats of combustion of vulcanized and unvulcanized rubber-sulfur mixtures, have been reported by several observers. The results obtained by the various investigators are not in satisfactory agreement. The values reported in the literature for the heat of combustion of rubber vary over a range of about 4.5 per cent, and the two recent sets of data on the heat of combination of rubber and sulfur differ radically, as may be seen from Fig. 2. It was thought that these differences might be due, in part at least, to differences in the composition of the rubber, and that more consistent results might be obtained by using purified rubber. The data presented in this paper were obtained on samples of purified rubber and on compounds of purified rubber and sulfur prepared in connection with an investigation of the electrical properties of rubber and rubber-sulfur compounds by Scott, McPherson, and Curtis.

High temperature and fire properties of sustainable syntactic foam reinforced by end‐of‐life tyre‐derived rubber particles

“…It is worth noting that this increase in THR for SYN (1:5) occurred with only a 7% increase in the total weight of combustible constituents, such as epoxy and rubber particles, relative to the baseline foam. This substantial enhancement in THR can be attributed to the significantly higher heat of combustion of tyre-derived rubber particles, which falls between 39 and 45 MJ/kg, 36,37 as opposed to bisphenol resins with a heat of combustion of 31 MJ/ kg. 38 Given the heat of combustion values ranging between 39 and 45 MJ/kg, it was expected that SYN (1:5) would generate between 17% and 25% more heat per unit mass compared to the baseline foam.…”

Rubber research and technology at the National Bureau of Standards/

“…The purified material contains about 99.5 percent of rubber hydrocarbon. Rubber purified in this manner was used in investigations of crystallization [24], specific heat [41], specific volume and expansivity [42] , heats of combustion [43] , electrical properties [48,4ST], refractive index [57], photoelasticity [58], and heats of reaction [70] A different method of purification, calling for digestion of the proteins in latex with the enzyme trypsin, has also been developed [12] . Rubber purified by this method has been used in investigations [11,12] of gel content, crystallization, and carbon-hydrogen ratio, as well as in studies of the stress-strain behavior of sol and gel rubbers [33], X-ray diffraction [59 to 61], crystallization [28], and molecular distillation [10].…”