The contact of diesel fuel with engine subsystems demands a good wear resistance. Lubricity is an important feature for integrity of injection system and the sulphur composites are primarily responsible for lubrication of the injector nozzle. Biodiesel is responsible for partially restoring the lubricity of diesel fuel that presents low levels of sulphur composites and, furthermore, it causes less pollution than diesel fuel. The lubricity is measured through the wear scar diameter following the ASTM D 975 standards. However, the friction and wear with light loads of micro/nanocomponents are highly dependent on surface interactions that can be evaluated by microscopy techniques. This study aimed to measure and to analyze the biodiesel lubricity and their blends (B5, B20) with diesel by observing the wear scars of discs using the scanning electronic microscopy (SEM), atomic force microscopy (AFM) and micro roughness techniques. The fuels performance was evaluated using HFRR tribometer. The tests conditions were based on standard ADTM D-6079-04. The coefficient of friction was measure during the test. After the test, the worn ball and disc were analyzed by SEM, AFM and profilometer. The results showed that the addition of biodiesel in diesel improve the tribological performance of fuel. Also, the just WSD value is not sufficient to evaluate the lubrication ability of a fuel. Analysis of the worn disc surfaces proved to be compatible with WSD number and also more sensitive to these kinds of fuels, showing mainly the form and intensity of the wear.

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PALAVRAS-CHAVE:Petróleo, riscos ambientais, perfuração, sonda, mapa de riscos. KEY-WORDS: petroleum, environmental risks, drilling rig, the risk maps. GREEN FUELS OF BRAZIL -EVALUATION OF LUBRICITY OF B5 BIODIESEL AND RICIN AND COCONUT OILS ABSTRACT

Nowadays, is expected that for most materials to be environmentally friendly. Besides, waste from end-of-life products may be considered a secondary source of materials with an energetic advantage due to its high energy content. This paper deals with the study of friction and wear characteristics of Glass fibre-reinforced polymer (GFRP) composites with polyester/glass fiber (P/GF) waste as filler, replacing the widely used calcium carbonate (CaCO 3 ). Polyester composites based on two or three components, using a combination of polyester, CaCO 3 , GF, and GF waste, were produced. Pin-ondisc sliding wear test was performed using a polished stainless steel counterface. Roughness, surface energy, and hardness of the composites were characterized before the tests. The GF content (15, 25, 35, and 50 wt.%), the sliding velocity (0.021 and 0.042 m/s), and the normal load (1, 5, and 10 N) were varied. Based on the experimental results, it was observed that the friction coefficient and wear rate were influenced by material composition, surface roughness and energy, adhesive, and abrasive contact mechanisms. P/GF composites having P/GF waste presented enhanced performance considering friction and wear in relation to those with CaCO 3 in their composition.

In this work, the performance of polyester (P)/glass fiber mats (G) and P/G/calcium carbonate (CaCO 3 ) composites was compared with that of P/G/ fiberglass waste composites. The residues used were conventional P/G postconsumer light resin-transfer-molding parts, obtained via knife or ball milling. Composites with up to 50 wt % reinforcement were prepared by hot compression molding and characterized via physical (density and water sorption), thermal (thermogravimetry and burnout), and mechanical (impact, Barcol hardness, and tensile) testing. The results show that the simple grinding and reincorporation of the composite residues yielded new composites with generally worse characteristics than the ones with calcium carbonate. Then, the waste was sorted by removing most of the pure resin particles from it. This yielded a resin-rich fraction, which could be better used for energy recovery and resin-covered fibers. The use of the latter as a filler yielded composites with better overall properties than those with calcium carbonate for a controlled amount of W; thus showing potential use as a replacement for the commonly used inorganic filler, maintaining the mechanical properties, decreasing the raw material cost, and reducing the amount of composite waste discarded in the environment.