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Extensional rheology of raw natural rubber from new clones of Hevea brasiliensis
Author(s) -
Lotti Cybele,
Moreno Rogério M.B.,
Gonçalves Paulo de S.,
Bhattacharya Satinath,
Mattoso Luiz H.C.
Publication year - 2012
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.22056
Subject(s) - hevea brasiliensis , natural rubber , extensional definition , rheology , polymer science , hevea , viscosity , materials science , clone (java method) , biopolymer , polymer , composite material , biology , paleontology , tectonics , dna , genetics
Natural rubber (NR) is a biopolymer whose properties depend on the molecular structure of the 1,4‐ cis polyisoprene chains, nonrubber constituents, environmental conditions, etc. NR has been characterized by Mooney viscosity, Wallace plasticity, nitrogen content (% N ). However, these cannot effectively account for clone's differences. The aim of this work is to use extensional rheology to characterize and differentiate NR samples as for clone type and the season of the year in comparison to the traditional characterizations. Three IAC 300 series and RRIM 600 clones of Hevea brasiliensis tapped between October 2006 (Oct_06) and August 2008 (Aug_08) were investigated. IAC 329 clones showed the least susceptibility to seasonal changes, whereas RRIM 600 was the most influenced. An opposite trend between extensional viscosity (η E ) and % N was established. The former was very sensitive to changes in the molecular structure of NR, being fundamental for monitoring purposes and strategic development of new rubber tree clones. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers