A PRELIMINARY INVESTIGATION INTO THERMAL SPRAY AND OTHER METAL/POLYMER DEPOSITION PROCESSES AND THEIR POTENTIAL USE IN THE OIL INDUSTRY

Polymeric coatings are being used in a raising number of applications, contributing to protection against weather conditions and localized corrosion, also reducing erosion wear. The coatings may be deposited by various processes and thermal spray is being recently investigated as a new alternative. This paper reports an exploratory study into various polymer deposition processes and evaluates their influence on the quality of the produced coating, concerning dispersion, cohesiveness and adhesion onto steel substrates. Different content aluminum/MDPE (medium density polyethylene) mixtures and processing parameters were studied as an attempt to identify the most promising parameters regarding their future application to produce coatings for the oil industry. The material characterization was carried out via mechanical testing (ASTM D638). The coating adhesion was evaluated by bend and ASTM C633-79 tensile tests. A microscopy evaluation of the coatings was also carried out. The produced films showed low friction surfaces and adequate adhesion to steel substrates. The presence of MAN (maleic anhydride) in the composite was responsible for the MDPE to recover its ductility, with a small increase of strength and rigidity, as well as a significant enhancement of coating adhesion to substrate

STUDI ES ON NATURAL FI BERS OF BRAZI L AND GREEN COM POSI TES

Abstract: Natural resource of any country is one of the contributors for its GDP (gross domestic product). Brazil has a number of such resources, which are abundantly available and being not used to its full potential. Plant fibers belong to this category. This paper presents the data on the availability of some of the resources of such fibers, their production, structure and properties along with their present uses. It also briefly gives perspectives being used for their better utilization while giving a brief overview of the R&D carried out in the country in general and UFPR in particular in the synthesis of composites, to meet the ecological aspects and their increased use

IFSS, TG, FT-IR spectra of impregnated sugar palm (Arenga pinnata) fibres and mechanical properties of their composites.

This study aimed to investigate the effect of resin impregnation on the interfacial shear strength (IFSS), thermogravimetric (TG) and fourier transform infrared (FT-IR) of sugar palm (Arenga pinnata) fibres. In addition, the effect of resin impregnation on the mechanical properties of sugar palm fibre reinforced unsaturated polyester (UP) composites was also studied. The fibres were impregnated with UP via vacuum resin impregnation process at a pressure of 600 mmHg for 5 min. Composites of 10, 20, 30, 40 and 50 % fibre loadings were fabricated and tested for tensile and flexural properties. It was observed that the impregnation process caused the fibres to be enclosed by UP resin and this gave a strong influence to the increase of its interfacial bonding by the increase of its IFSS from single fibre pull-out test. It was also observed with TG and FT-IR spectra that the impregnated fibre had lower moisture uptake than the control and there was no significant increase in thermal stability of the impregnated fibre. The sequence of fibre decomposition started from the evaporation of moisture, hemicelluloses, cellulose, lignin and finally ash content and the presence of these components were proven by FT-IR spectra. For the composite specimens, due to the high interfacial bonding of the impregnated fibre and the matrix, the impregnated composites showed consistently higher tensile strength, tensile modulus, elongation at break, flexural strength, flexural modulus and toughness than the control samples. It was also observed that 30 % fibre loading gave optimum properties