GALIANI, P. D.

GONÇALVES, P. de S.

MATTOSO, L. H. C.

MORENO, R. M. B.

RCAAP - Repositório Científico de Acesso Aberto de Portugal

Dynamic-mechanical analysis of natural rubber from new clones (IAC 300 series).

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Dynamic-mechanical analysis of natural rubber from new clones (IAC 300 series)  Rogério M. B. Moreno1, Patrini Danielle Galiani2, Paulo de S. Gonçalves3, Luiz H. C. Mattoso4 1,4 Embrapa Instrumentação Agropecuária, São Carlos, SP, Brazil 2Departamento de Química, Universidade Federal de São Carlos, São Carlos, SP, Brazil 3Programa Seringueira, Instituto Agronômico, Campinas, SP, Brazil  There is a deficit between consumption and production of natural rubber (NR) in Brazil, where the country has imported must of NR from Asia to supply internal market. Nowadays the country needs to import nearly 60% of the consumed NR1. To change this situation, it is important to invest in research in this area. In this sense, this work is a part of a project devoted to the development of NR in the São Paulo State, which is already the largest NR producer of the country. In this work, it is presented the results of an evaluation of the dynamic-mechanical properties of raw NR from new IAC 300 series clones, namely: IAC 328-333, IAC 335, IAC 337 (GT 1 – witness). In relation to the witness (GT 1), the new IAC 300 series clones (328, 329 and 330) presented significantly higher values of the storage modulus [E’max (Mpa)] and lower variation in values of the E’max between other IAC 300 clones and the witness (Figure 1). The glass transition temperatures (Tg), measured at the maximum of the tan δ curves as a function of the temperature, without varying in relation to the type of clone (Figure 2).  The IAC 333 had the lower Tg value and IAC 328 the highest. The tan δ values which were obtained are inside the range of the values usually displayed for viscoelastic materials (0.001 < tanδ < 3)2. Keyword: natural rubber, clones, rubber tree, dynamic-mechanical properties. The authors acknowledge the financial support provided by FAPESP, CNPq and CAPES. -60 -40 -20 0 20 40 60 80 100 120-0.50.00.51.01.52.02.53.03.5logE' (MPa)Temperatura ( oC ) E 'IAC328 E 'IAC329 E 'IAC330 E 'IAC331 E 'IAC332 E 'IAC333 E 'IAC335 E 'IAC337 E 'GT1 -60 -40 -20 0 20 40 60 80 100 1200.00.20.40.60.81.01.21.41.61.82.0tan δTemperatura ( o C )                              Tg ( oC ) IAC 328          -46,76    IAC 329          -49,54 IAC 330          -49,13 IAC 331          -49,31 IAC 332          -49,28 IAC 333          -50,49 IAC 335          -49,80 IAC 337          -49,43 G T1               -49,26   Figure 1 – Log(E’) versus temperature for NR from new clones IAC 300 series. Figure 2 – tan δ versus temperature for NR from new clones IAC 300 series.  [1] International Rubber Study Group, Rub. Stat. Bull. 60, 9 (2006). [2] S. V., Canevarolo - Parte 1: O amortecimento (tanδ). Seção tecno-científica, Associação Brasileira de Polímeros, 36 (1991). rogerio@cnpdia.embrapa.br, Rua XV de Novembro, 1452, C.P.741, CEP: 13. 560-970, São Carlos-SP, Brazil.  

Dynamic-mechanical analysis of natural rubber from new clones (IAC 300 series).

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RCAAP - Repositório Científico de Acesso Aberto de Portugal

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