As the most desirable consequence, the ultrasonically devulcanized rubber can be reprocessed and revulcanized in a manner similar to that employed with unvulcanized
Storage modulus (G') of the unvulcanized
rubber compound was measured and the difference in G' at low (0.56%) and high (100%) strains ([DELTA]G') was used to represent the magnitude of filler-filler interaction.
The DSC thermograms of the unvulcanized
samples based on the second heating scan performed between -80 and 20[degrees]C are shown on the left side of Figure 3 and the obtained [T.sub.g] values are summarized in Table 1.
The properties of unvulcanized
rubbers have been interpreted by considering how these materials are viscoelastic with low mechanical strength.
Costs associated with cleaning method development and validation are minimal relative to those required for other processes where unvulcanized
silicone-drug mixtures contact numerous surfaces of both mixing and fabrication equipment.
Among the topics are the basic concepts and behavior of rubber elasticity, characterizing structure in the science and technology of elastomers, the viscoelastic behavior of rubber and dynamics of blends, the rheological behavior and processing of unvulcanized
rubber, vulcanization, reinforcing elastomers by particulate fillers, the science of rubber compounding, the strength of elastomers, the chemical modification of polymers, tire engineering, and recycling rubbers.
(82) A second, smaller, company to make rubber shoes appeared, as well as a workshop specializing in recapping old tires with imported "camelback." (83) The latter was an unvulcanized
rubber compound, which was cemented onto the tire after the old tread had been buffed off and was then vulcanized onto the tire in a mold.
At around the same time Uniroyal was developing and launching its TPR, a host of competitive products began to appear, most of which were blends of unvulcanized
EPM or EPDM elastomers with PP and/or PE.
In general, TPOs are produced by blending a thermoplastic such as polypropylene with an unvulcanized
elastomer such as EPDM.
* RPA (rheology) is used to measure viscoelastic properties and process simulation of raw rubber, as well as unvulcanized