In this work phenolics pre-polymer (resol type) and pre-polymer lignin-phenol (40% w/w sugar cane bagasse lignin) were synthesized. These pre-polymers were used to prepare matrice of several composites reinforced with bagasse fibers, sisal fibers and curaua fibers. The bagasse and sisal fibers were extracted with cyclohexane/ethanol. The improvement in impact strength was small for sugar cane bagasse reinforced composites and it was very significant for sisal reinforced composites. The curaua fibers were submitted to the same extration above mentioned and then treated with a 10% solution of NaOH. The composites containing treated curaua fibers also presented improvement in the impact strength.
Lignin was employed in rubberwood-polypropylene (RW-PP) composites to serve as a bridging agent between polar wood filler and non-polar PP. Incorporation of lignin in the composites was able to improve the flexural and tensile properties of the composites. SEM showed evidence of improved adhesion as the result of the addition of lignin. Activation of the wood surface with sodium hydroxide (NaOH) improved the flexural and impact properties of the composites. The tensile modulus was improved, espe...
Abstract The mechanical properties of sisal fibre composites (randomly oriented) of several thermoset resin matrices, [polyester, epoxy, phenol-formaldehyde] and a thermoplastic matrix [low density polyethylene (LDPE)] were evaluated with respect to fibre length and fibre loading. All the composites showed a general trend of increase in properties with fibre loading. However, the optimum length of the fibre required to obtain an increase in properties varied with the type of matrix. Among polyes...
#1Chien-Ping Ju(NCKU: National Cheng Kung University)H-Index: 25
#2N. Murdie(SIU: Southern Illinois University Carbondale)H-Index: 1
Abstract Conventional and polarized light microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) are used to examine the microstructure of a two-dimensional mesophase pitch fiber, phenolic resin char plus chemical vapor infiltrated (CVI) matrix carbon-carbon composite. Optical and SEM results indicate that the pitch fiber bundles are bonded by interbundle resin char. Each individual fiber within a bundle is surrounded by two distinctive CVI carbon layers. The m...
#1E.T.N. Bisanda(UDSM: University of Dar es Salaam)H-Index: 1
Abstract Sisal fibre is a vegetable fibre having a specific strength and stiffness that compare well with those of glass fibre. The fibre surface can be modified by chemical treatment to create an interface that is fairly compatible with most thermosetting resin matrices. Most synthetic resins are, however, more expensive than the sisal fibre, making these composites less attractive for low -technology applications. Cashew nut shell liquid (CNSL) has been identified as a cheap naturally occurrin...
Rotomolding is a versatile process used in the manufacture of thermoplastic polymeric materials to produce large hollow plastic parts. The aim of this review article was to discuss the rotomolding ...
O EPS (poliestireno expandido) e um polimero resultante da polimerizacao do estireno em agua e e imensamente utilizado para a confeccao de embalagens. Em vista disso, e produzido em grandes proporcoes. Por outro lado, outro importante residuo produzido e o bagaco de cana-de-acucar, por conta da grande producao de acucar e etanol no Brasil. Deste modo, este trabalho propoe o uso destes dois residuos, combinando as suas propriedades em um unico material, um composito. Para a obtencao das fibras ce...
: Nowadays, there is growing worldwide interest in the use of natural renewable materials to replace synthetic polymers or improve the properties of current materials. Natural fibers seem to offer a great opportunity in this respect, and among them curaua (Ananas erectifolius L. B. Smith) fiber has unique properties, such as high strength, low density, a fine structure and high cellulose content. Due to its mechanical properties and recyclability, it is of great interest for developing composite...
We obtained polymer films from corn starch with lignin incorporation as lignosulfonate. The motivation is the use of starch in obtaining films, due to their potential for biodegradation, and the use of lignosulfonate waste from the pulp and paper industry. To obtain films of lignosulfonates various powders of lignosulfonate were used, varying type and proportion (1% to 4%). Analyses were performed on polymer films to compare thermal properties by Differential Scanning Calorimetry, and tensile pr...
Abstract This research proposes the development of polymeric composites reinforced with natural fibres to become stronger the damaged timber structures and proposes thermal and mechanical characterization of these composites. Fibres with larger structural applications are glass and carbon fibres but the use of natural fibres is an economical alternative and possesses many advantages such as biodegradability, low cost and is a renewable source. Woven sisal fabric was submitted to heat treatment b...
Glyoxal, which can be obtained from biomass (as by lipids oxidation), is non-toxic and non-volatile. It was used as a substitute of formaldehyde, which does not have these properties, in the synthesis of a novolac-type phenolic resin, using oxalic acid as a catalyst, which can also be obtained from renewable sources. The glyoxal-phenol resin was used in the preparation of composites reinforced with microcrystalline cellulose (MCC 30, 50, and 70% w/w). Scanning electron microscopy (SEM) images of...
Last. Antonio Donato Nobre(INPE: National Institute for Space Research)H-Index: 39
view all 6 authors...
The Amazon Rain Forest has attracted worldwide attention due its large scale services to climate and also due to the green house gas emissions arising from deforestation. Contributing to the later and detrimental to the former, timber logging in the region has very low efficiency (only 16% in the production chain). Such timber extraction, often referred to as selective logging, has been claimed as a sustainable extractive industry, because the forest is said to restore itself through regenerativ...