Periodicals of Engineering and Natural Scinces ISSN 2303-4521 Vol.6, No.1, Octobar 2018, pp. 154~160 Available online at: http://pen.ius.edu.ba DOI: 10.21533/pen.v6i1.167 154 A Review on Devulcanization of Waste Tire Rubber Ali Gursel 1 , Enes Akca 2 , Nuri Sen 1 1 Departement of Mechanical Engineering, Faculty of Engineering, Duzce University 2 Departement of Mechanical Engineering, Faculty of Engineering and Natural Sciences, International University of Sarajevo Article Info ABSTRACT Article history: Received Apr 17 th , 2018 Revised September 24 th , 2018 Accepted Octobar 15 th , 2018 Rubber has become an indispensable material for the technological development of civilization, including simple balloon and complex rocket propellant. Rubber Industry worldwide is using on an average 50% of raw materials. These materials were mostly petroleum-based, except natural rubber (NR), steel cord and bead wire. Using of these petroleum-based raw materials not only depletes natural resources, but also produces more extreme environmental hazards. The waste tire rubber problem is of great magnitude and has far reaching environmental and economic implications. There are some ways for recycling of rubber, such as reclaiming technology, surface treatment, grinding and pulverization technology, devulcanization technology. Methods of devulcanizing rubber (or elastomers) have been researched almost since the time of the discovery of the rubber/sulfur vulcanization process. By devulcanization process the cross-links in the structure of rubber are broken and devulcanized rubber can be revulcanized into a raw material for rubber industry, which is a highly valued form of waste rubber. This study provides a review of the recent advances in understanding of methods of recycling rubber and claims that the capacity of thermomechanical and mechanochemical devulcanization methods of recycling waste tire rubber can be improved in future studies. Keyword: Waste tire rubber Recycling Devulcanization Corresponding Author: Ali Gursel, Departement of Mechanical Engineering, Duzce University, Düzce Üniversitesi Konuralp Yerleşkesi, Konuralp Merkez/Düzce 81620, Turkey. Email: aligursel@duzce.edu.tr 1. Introduction The annual consumption of natural rubber is more than 15 million tons, and the output of rubber products is more than 31 million tons worldwide [1]. With the increasing demand for more rubber products, a lot of waste rubber is produced every year in the world. The main source of waste rubber products is discarded waste tires, rubber pipes, rubber belts, rubber shoes, edge scraps, and waste products that are produced in the rubber processes and others [2]. The handling of such large volumes of discarded elastomeric materials poses a serious environmental problem that must be faced by the scientific community. As the options of disposals such as landfills, stockpiling, and incineration become increasingly less viable due to cost and environmental concerns, a wide variety of reclaiming methods [3-5] have been investigated to recycle waste rubbers. The methodologies developed have enabled reutilization of waste rubber products especially tires only partially. The need for total recycling requires continuous development of alternative methods. The devulcanization and reutilization of cross-linked elastomers are very difficult because of the three- dimentional network. This network makes the material insoluble and nonmelting. The yearly global consumption of vulcanized elastomer is 17.2 million tons [6] of which approximately 39% is natural rubber and the remaining 61% consists of other synthetic rubbers. To improve the properties of rubber vulcanization is required [7].