Desenvolvimento e caracterização de compostos elastoméricos de poli (butadieno-co-estiremo) com componentes de fonte renovável

Abstract

Proposing an elastomeric composition becomes a complex development considering the need for synergy and compatibility of the components. The replacement of components traditionally used by others, from renewable sources, becomes a challenge for work in the area of elastomers. Silica and carbon black are the reinforcement fillers most used in elastomeric compositions, however, obtaining and using them, can result in damage to the environment and human health. The same happens in relation to the plasticizers used in elastomeric compounds, which contain a high content of polycyclic aromatics (PCA), being requested to decrease their use in tire industries. In order to use reinforcement and plasticizer loads from natural sources to replace elastomeric components, the performance of an elastomeric compound by partial replacement of carbon black with nanofibrillated cellulose (CNF) provided with Eucalyptus spp shavings, is evaluated in this work. such as the use of palm oil instead of aromatic oil. CNF was obtainedby grinding in a micronizer mill with a content of 2% by mass. As a characterization of the raw material, the thermal, chemical, morphological properties and particle size analysis of the cellulose suspension were evaluated by the particle size analyzer (DSL). From the nonvulcanized compound, rheometric properties were evaluated. From the vulcanized material, the physical, mechanical, dynamic-mechanical properties, cross-link density and the swelling index in solvents were evaluated. The mechanical properties are also evaluated, after accelerated heat aging after 7 and 14 days of exposure. The main results obtained are the presence of CNF clusters observed by scanning electron microscopy (SEM) with nanofibers with diameters from 100 - 85 nm. The DSL showed nanoparticles from 1 to 100 nm. The rheological properties showed lower values for the parameters ts1, t90 and MH, ML comparing the samples with the presence of nanofibrilates and those with carbon black. For tear resistance properties, samples with the presence of CNF obtained 48% more resistance than samples with NC, in the modulus of elasticity, cross-link density and swelling index, a better performance was also obtained for the samples. with CNF, in addition to presenting a similar behavior in the hardness property between samples with the presence of nanofibrilates and those with carbon black. In relation to plasticizer oils, palm oil, a substitute for aromatic oil, was found to be similar in the results of the evaluated properties, which can replace aromatic oil. In this way, the results converge in an improvement in the mechanical properties, be it in the properties of the compounds as proposed or by the use of products from renewable sources, which brings benefits for all. [resumo fornecido pelo autor]