Reciclagem de borrachas: uma abordagem sobre processos e impactos ambientais

Abstract

Rubber wastes represent a growing and important environmental issue. Despite the existence of legislation, the increasing demand for rubber products, combined with their improper postconsumer disposal, have caused several environmental, social, and economic impacts. Due to the three-dimensional structure formed by cross-links during vulcanization, elastomeric materials undergo limited reuse pathways. To overcome this limitation, different recycling routes have been applied, such as grinding, energy recovery and, more recently, the devulcanization technique, in which the cross-links are selectively broken, allowing the rubber to be reprocessed and remolded for different applications. This work aims to describe different routes for rubber waste recycling, depicting different applications to reinsert these materials into the production chain. Furthermore, the life cycle assessment (LCA) methodology was applied to compare the eco-impacts resulting from the energy recycling of different rubber materials (natural rubber, SBR, BR and silicone) in terms of the following categories: global warming, human toxicity (carcinogenic effects), and scarcity of fossil resources. Natural rubber presented the smallest eco-impacts when subjected to energy recycling. SBR and BR presented intermediate impacts, also presenting equivalent results, in view of their similar composition. On the other hand, silicone rubber presented the greatest impacts in all analyzed eco-impact categories.