Table of Contents
ISRN Polymer Science
Volume 2013, Article ID 340426, 9 pages
Research Article

Biodiesel as a Plasticizer of a SBR-Based Tire Tread Formulation

1Dipartimento di Scienze Ecologiche e Biologiche, Università della Tuscia, Largo Università snc, 01100 Viterbo, Italy
2Soc Lupi Chemical Research srl, Via Casilina 1626A, 00133 Rome, Italy
3University of Rome Tor Vergata, Via della Ricerca Scientifica, 00133 Rome, Italy
4Istituto di Metodologie Chimiche, CNR, Via Salaria Km 29,300, Monterotondo Stazione, 00016 Rome, Italy

Received 25 January 2013; Accepted 17 February 2013

Academic Editors: T. R. Chantara, S.-H. Jafari, G.-H. Kim, B. Kiskan, and G. Lapienis

Copyright © 2013 Franco Cataldo et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The solubility parameter of a series of methyl esters of fatty acids, the components of biodiesel, was calculated using the group incremental method proposed by Van Krevelen. The solubility parameter of biodiesel was compared with that of a series of rubbers like EPDM, butyl rubber, polyisoprene, polybutadiene, SBR (with different content of styrene), and nitrile rubber (with different content of acrylonitrile) showing that biodiesel is an effective solvent of all the above mentioned rubbers with the exclusion of nitrile rubber. Indeed, it was experimentally verified that polyisoprene, polybutadiene and SBR are easily soluble in biodiesel while polystyrene gives a cloudy solution. Considerations on the solubility parameter of the biodiesel and of a series of rubbers have led to the conclusion that biodiesel behaves essentially as an internal lubricant in a diene rubber matrix, the same situation occurs with the common aromatic mineral oil plasticizer known as T-RAE. The experimental evaluation of biodiesel as plasticizer in an SBR-based rubber compound in comparison to an aromatic mineral oil have led to the primary conclusion that biodiesel is reactive with the sulphur curing agent subtracting sulphur to the crosslinking polymer chains and leading to a vulcanizatewith lower moduli, tensile and hardness and higher elongationsin comparison to a reference compound fully plasticized with an aromatic mineral oil. However, biodiesel seems a good low temperature plasticizer because the low elastic modulus observed is desired in a winter tire tread for a good grip on snow and ice. The present work is only an exploratory work, and the tire tread formulation with biodiesel was not optimized.