An innovative material based on natural rubber and leather tannery waste to be applied as antistatic flooring

In recent decades, the production chain of beef and bovine leather has grown significantly because of an increase in the world's population and improved access to consumption. However, the generation of waste derived from this sector has grown simultaneously, and consequently, improved ways of adding value, reusing, and disposing these waste materials are being sought. In this article, we present a new and innovative composite material based on vulcanized natural rubber (NR), carbon black (CB), and leather waste (NR/CB/leather). The NR/CB/leather composites were prepared by thermal compression with 60 phr of CB and 60 or 80 phr of leather waste. In accordance with Brazilian sanitary laws, we exposed these composites for 24 h to bleach (B) and a disinfectant with the aim of simulating a true everyday cleaning use. The deconvolution of the impedance semicircles was carried out, and two relaxation phenomena around linear relaxation frequencies of about 10(5) and 10(6) Hz were found and associated mainly with charge carriers from CB and leather waste. With the addition of leather, the electrical conductivity of the composites increased two orders of magnitude from 5.70 x 10(-6) for the NR/CB to 7.97 x 10(-4) S/cm for NR/CB/leather-60 phr B. These results point to the possibility of using these composites as an antistatic flooring once they exhibit acceptable values of electrical conductivity and once they withstand, from the structural, morphological, and electrical point of view, exposure to sanitizing agents. Furthermore, the production of these composites will add value to and enable an environmentally acceptable disposal of leather waste. (c) 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41297.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Evaluation of the properties of natural rubber bio composite and guava residue (Psidium guajava L.) as sustainable application

In juice and pulp extraction, about 10% of fruit waste is generated, which often ends up in landfills that can cause environmental damage, serve as food for insects and rodents, and cause health problems for humans. In this work, micronized guava waste was used as a filler in vulcanized compounds in natural rubber. Mechanical properties such as hardness, tensile strength, tear resistance, and abrasion resistance were evaluated, as well as thermal properties such as thermogravimetric analysis, in addition to scanning electron microscopy, X-ray fluorescence, elemental analysis, and infrared spectroscopy. According to the results of the mechanical properties tests, the addition of up to 20 phr of the filler tends to improve the tensile strength of the composites, resulting in an increase in the density of cross-links obtained through the Flory-Rehner method. The thermal behavior analyzed by TGA and FTIR spectra were not affected by the incorporation of fillers