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Natural Rubber from Alternative Sources. the Key Role of Low Molecular MASS Components
Thursday, October 16, 2014: 8:00 AM
Session B-Rm #205 (Nashville Convention Center)
Maurizio Galimberti1, Sara Musto
2, Vincenzina Barbera
3, Valeria Cipolletti
1, Laura Tinč
2, Attilio Citterio
4, Gaetano Guerra
5 and Luca Castellani
6, (1)Chemistry, Materials and Chemical Engineering, Politecnico di Milano, Milano, Italy, (2)Politecnico Milano, Milano, Italy, (3)Chemistry, Materials and Chemical Engineering, Politecnico Milano, Milano, Italy, (4)Chemistry Materials and Chemical Engineering, Politecnico Milano, Milano, Italy, (5)Universitą Salerno, Fisciano, Italy, (6)Pirelli Tyre, Milano, Italy
Natural rubber (NR) is the most important rubber, with worldwide consumption of about 12 million tonn/year. Such a large commercial success is mainly due to NR outstanding properties: great strength and tack in the uncrosslinked state and very high tensile strength and crack growth resistance in the crosslinked state. More than 2000 species of plants produce poly(1,4-cis-isoprene), but only
hevea brasiliensis is used for large scale NR application, such as the one for tyre compounds. NR from the
Hevea tree has nowadays to face some major problems: plantations located in relatively small geografic areas, diseases and predicted shortage. Research is thus active on alternative sources, such as
partenium argentatum, known as guayule and
taraxacum kok-saghyz, known as the russian dandelion, for large scale NR production.
In this contribution, direct comparison between NR from the mentioned natural sources and from Ziegler-Natta catalysts is presented. Chemical composition of poly(1,4-cis-isoprene) samples was determined.1 In particular, amount and structure of low molecular mass components were assessed. Strain induced crystallization and reinforcement, kinetics of vulcanization, interaction with fillers2, structure, properties and mechanism for the formation of nanocomposites were studied. Reactivity of poly(isoprene) chain and low molecular mass chemicals with sulphur based ingredients of rubber compounds was investigated. Findings were correlated with polymer molecular features and with the chemical composition of rubber samples. The key role played by low molecular mass components is discussed.
1 S. Musto, M. Galimberti, L. Tinè, A. Citterio, L. Castellani, M. Mauro, Presentation at European Polymer Federation Congress, Pisa (Italy), June 16–21, 2013
2 S. Agnelli, V. Cipolletti, S. Musto, M. Coombs, L. Conzatti, S. Pandini, T. Riccò, M. Galimberti eXPRESS Polymer Letters Vol.8, No.6 (2014) 436–449
