Abstract

CACERES SANDOVAL, Angélica Patricia  and  GAUTHIER-MARADEI, Paola. Thermogravimetric analysis as a new method to determine of total solid content (TSC) and dry rubber content (DRC) of natural latex. Rev. ion [online]. 2012, vol.25, n.2, pp.57-65. ISSN 0120-100X.

Natural rubber latex is the raw material for the manufacture of various products used in the industry and the quality of them is associated to the composition of fresh latex preserved. ASTM D1076 presents a method for the determination of TSC, DRC and VFA, among other natural rubber latex properties. This method turns out to be long and tedious, therefore it is looking for a way to characterize the natural latex to save time and to easy operation. The aim of this study is to determine the TSC, DRC and VFA in the natural latex by thermogravimetry. In order to achieve this objective, latex samples were submitted to thermogravimetric analysis under an inert atmosphere and the results were compared with those obtained in the methods described by ASTM D1076, achieving a viable method of characterization for the determination of TSC and DRC with an variance between two methods of 0.45 from the values obtained for TSC and an variance between two methods of 0.13 for DRC compared with the obtained at ASTM conditions. In the other hand, it was not possible to determine the VFA content by thermogravimetry because the mass loss of these compounds occurs in the same temperature range than the water. Additionally, a qualitative characterization by FTIR of the dense phase and the aqueous natural rubber was performed, which allowed the identification of functional groups corresponding to polyisoprene, proteins and carbohydrates in the dense phase of the latex.

Keywords : TGA; ASTM D1076; Hevea Brasiliensis; natural rubber.

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