State of the Art: Recycling of EPDM Rubber Vulcanizates

Abstract

Since the past few decades, environmental issues have become a serious concern in society. It is a requisite for the industry to minimize waste, in order to protect the environment from being polluted. The term waste here comprises processing waste and post-consumer waste. The amount of processing waste should not be underestimated since it might consist of approximately 10% of the total production. The recycling of EPDM rubber is an interesting topic, especially if considered in connection with the continuous market growth of EPDM. This paper is a summary of efforts that have been taken so far on this subject. Studies done on EPDM recycling include reusing EPDM as filler in new rubber products and chemical, thermal, and mechanical devulcanization of EPDM in order to achieve a material that resembles the virgin one and could be revulcanized. Such studies on EPDM recycling are discussed extensively and in the conceptual frame of more general rubber recycling processes.

Relationship among Vulcanization, Mechanical Properties and Morphology of Blends Containing Recycled EPDM

“…Finally, the residue was ground in a knife mill (Marconi, model MA 580, Piracicaba, SP, Brazil). The distribution of particle size was determined by granulometric analysis, according to American Society for Testing and Materials (ASTM) D5644-01, using the sieves with 20,25,28,35,48, and 65 mesh.…”

“…Although there is a loss of mechanical properties during the process, since the interaction between the vulcanized elastomer and the raw one is generally weak, its recovery may be advantageous when incorporated into new formulations, given the reduction in the cost of the final product, lower consumption of energy and raw materials, and the non-generation of hazardous residues [9][10][11][12][13]. In this way, some authors have studied blends containing at least one phase composed of a recycled elastomer [14][15][16][17][18][19][20] as a viable economic alternative and as an environmentally friendly solution to solid residues, obtaining satisfactory results. Some authors have shown that the vulcanization of blends containing a ground recycled phase is complex [14].…”

Comparative study of the presence of latex and polychloroprene in the behavior of sintered powder EPDMCR, ethylene-propylene- diene-monomer crumb rubber

“…Scanning electron microscopy was applied in order to analyse the polymer fractures, using a FEI 6 QUANTA 200 (FEI COMPANY, Hillsboro, USA). The micrographs were obtained in the microscope in ambiental mode (ESEM), which does not require the coating of gold or any other material for a correct visualisation.…”

“…They represent 7% of the world's rubber consumption, and their various applications represent the second most used rubber product, coming second only to natural rubber for pneumatic tyres [6].…”

“…Respect to the research concerning the recycling of EPDM would include the following references [6,8,[10][11][12][13][14][15][16]. 3 Once EPDM has finished its useful life in the application for which it was originally designed, the material is available as a waste product.…”