Abstract: A process for preparing thermoplastic rubbers from blends of vulcanized rubber scrap materials and virgin Natural Rubbers is provided comprising blending the vulcanized rubber scrap materials with virgin Natural Rubbers (NR) on a two roll mill or an internal mixer to form a polymeric mixture, followed by passing the polymeric mixture with an olefinic plastic through a twin screw extruder along with devulcanizing additives at elevated temperatures. The plastic resin may be a virgin resin, a recycled resin or a mixture thereof. The process is termed “dynamic devulcanization” to denote that the rubber scrap material is being devulcanized and intimately homogenized with virgin NR while it is being blended with the plastic resin to form the said thermoplastic natural rubber. A compatibilizing agent such as phthalic anhydride is introduced at the tail end of the twin-screw extruder to enhance the interface adhesion between the devulcanized rubber, virgin NR and the plastic resin.

Abstract: This invention relates to an asphalt composition cured with non-free sulfur components that enhance its elastic properties and at the same time increases its resistance to degradation due to high heating for prolonged period as practiced in asphalt preparations for road pavement.

Abstract: This invention provides a novel composite of bitumen and recycled polymers from post consumer and pre consumer manufacturing scraps for use in asphalt to increase its viscosity at higher temperature, desirable in pavements of warmer regions. This additive also improves tackiness for use in asphalt sealant applications and roofing membrane. This invention meets federal government objective of increasing post consumer wastes in asphalt.