Published Date 1 March 2012, Vol.87(4):2563–2568,doi:10.1016/j.carbpol.2011.11.041
Author
Andréia A. Morandim-Giannetti a
José Augusto M. Agnelli b
Bruno Z. Lanças a
Rodrigo Magnabosco c
Suzan A. Casarin b
Sílvia H.P. Bettini b,,
aDepartment of Chemical Engineering, Centro Universitário da FEI, Av. Humberto de Alencar Castelo Branco, 3972. São Bernardo do Campo, CEP: 09850-901 São Paulo, Brazil
bDepartment of Materials Engineering, Universidade Federal de São Carlos, Rod. Washington Luiz, km 235, São Carlos CEP: 13565-905, São Paulo, Brazil
cDepartament of Metallurgical and Materials Engineering, Centro Universitário da FEI, Av. Humberto de Alencar Castelo Branco, 3972. São Bernardo do Campo, CEP: 09850-901 São Paulo, Brazil
Received 8 October 2011. Revised 8 November 2011. Accepted 9 November 2011. Available online 22 November 2011.
Abstract
PP/CF composites were prepared and the effect of lignin incorporation in the presence and absence of compatibilizer (maleic anhydride grafted polypropylene, PP-g-MA) was investigated by means of mechanical, thermal and morphological properties. Lignin added to the composite was obtained by the Acetosolv process. The composites were prepared in a Haake torque rheometer and assessed by means of tensile testing, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The results showed that in the absence of PP-g-MA, incorporation of lignin did not affect tensile strength and in its presence this property was reduced. Thermal analysis revealed that incorporation of lignin in the composites resulted in increase in both the initial thermal decomposition temperatures and oxidation induction times.
Highlights
► Lignin as additive tends to coat fibers and protect against thermal degradation. ► Lignin can be used as primary antioxidant in PP/coir composites. ► Studies on the action of natural fiber constituents allow insight into NFRC behavior. ► Studies on possible uses of lignin may be important for the paper industry.
Published Date 15 February 2013, Vol.92(2):1477–1483,doi:10.1016/j.carbpol.2012.10.056
Eldho Abraham a,b,d
B. Deepa b
L.A. Pothen b,,
J. Cintil c
S. Thomas c
M.J. John d
R. Anandjiwala d
S.S. Narine a
aTrent Biomaterials Research Program, Trent University, Peterborough, Ontario, Canada
bDepartment of Chemistry, Bishop Moore College, Mavelikkara, Kerala, India
cSchool of Chemical Sciences, Mahatma Gandhi University, Kottayam 686 560, Kerala, India
dFibres and Textiles Competence Area, CSIR, Materials Science and Manufacturing, PE, South Africa
Received 19 June 2012. Revised 24 September 2012. Accepted 22 October 2012. Available online 30 October 2012.
Abstract
The objective of this work was to develop an environmental friendly method for the effective utilization of coir fibre by adopting steam pre-treatment. The retting of the coconut bunch makes strong environmental problems which can be avoided by this method. Chemical characterization of the fibre during each processing stages confirmed the increase of cellulose content from raw (40%) to final steam treated fibres (93%). Morphological and dynamic light scattering analyses of the fibres at different processing stages revealed that the isolation of cellulose nano fibres occur in the final step of the process as an aqueous suspension. FT-IR and XRD analysis demonstrated that the treatments lead to the gradual removal of lignin and hemicelluloses from the fibres. The existence of strong lignin–cellulose complex in the raw coir fibre is proved by its enhanced thermal stability. Steam explosion has been proved to be a green method to expand the application areas of coir fibre.
Graphical abstract
Highlights
► An environmental friendly method for the extraction of coir fibre. ► Enhancing the effective utilization of coir fibre and to avoid its retting process. ► Reveals the presence of lignin–cellulose complex in the raw coir fibre. ► Successfully isolated a homogenous dispersion of nanocellulose fibrils.
Published Date February 2014, Vol.42(1):76–82,doi:10.1016/j.geotexmem.2013.07.004
Technical note
Author
Andréa Rodrigues Marques a,,,
Patrícia Santiago de Oliveira Patrício b,
Fábio Soares dos Santos a,
Monisa Lopes Monteiro a,
Denise de Carvalho Urashima c,
Conrado de Souza Rodrigues c,
aDepartamento de Engenharia Ambiental, Centro Federal de Educação Tecnológica de Minas Gerais – CEFET/MG, Av. Amazonas, 5253, Nova Suíça, 30.421-169 Belo Horizonte, MG, Brazil
bDepartamento de Química Industrial, Centro Federal de Educação Tecnológica de Minas Gerais – CEFET/MG, Av. Amazonas, 5253, Nova Suíça, 30.421-169 Belo Horizonte, MG, Brazil
cDepartamento de Engenharia Civil, Centro Federal de Educação Tecnológica de Minas Gerais – CEFET/MG, 7675, Nova Gameleira, Nova Suíça, 30.421-169 Belo Horizonte, MG, Brazil
Received 31 October 2012. Revised 27 May 2013. Accepted 4 July 2013. Available online 12 November 2013.
Abstract
In tropical countries where rainfall rates are high, and especially in deforested areas in the Atlantic Rainforest and Cerrado in southeastern Brazil, water is the dominant driving force of erosion. The most common method used to restore degraded tropical lands is to plant nursery-raised tree seedlings, but this method is not always practical and a variety of newer reforestation techniques have become available. Biodegradable coir geotextiles combined with native seeds can be used to restore degraded forest areas. The effects of the climatic conditions during a seasonal cycle of rain and drought were evaluated on the structural and mechanical properties of coir geotextile fibers that were treated, or not, with lime. Analyses of the tensile strength of coir fibers showed that after 12 months of exposure untreated fiber had retained 23% and treated fiber 19% of their initial strength. Two principal factors were considered in evaluating the structural properties of the coir fibers after environmental exposure: (i) initial cellulose retention and its stability after lime-treatment; (ii) lignin degradation and/or its loss to the environment. The structural changes seen by thermogravimetry (TGA) and Fourier Transforms in Infrared spectroscopy (FTIR) analyses explained the changes seen in coir mechanical properties. The greater cellulose contents of fiber structures treated with lime explained their greater tensile strength and high Young's modulus measures after the first three months of exposure in local weather conditions. Considering that lime treatment improved coir fiber properties, lime applications are indicated when coir geotextiles are to be used in acidic Brazilian Cerrado soils.
Published Date February 2015, Vol.41:184–190,doi:10.1016/j.polymertesting.2014.12.002
Test method
Author
Dijan Vinicius Osti de Moraes a,
Rodrigo Magnabosco a,,
Gustavo Henrique Bolognesi Donato a,
Sílvia Helena Prado Bettini b,
Marcela Caroline Antunes b,
aFEI University, Brazil
bUFSCar, Brazil
Received 31 October 2014. Accepted 5 December 2014. Available online 13 December 2014.
Abstract
The influence of loading frequency on the fatigue behaviour of a coir fibre reinforced polypropylene (PP) composite was studied. The mechanical behaviour was assessed through monotonic tensile and flexural tests, followed by cyclic bending fatigue tests employing a new specimen geometry, with loading frequencies ranging from 5 to 35 Hz. Results revealed that higher strain rates during monotonic loading lead to higher flexural strength, and higher loading frequencies in cyclic tests promote reduction in fatigue life. Fractographic examination showed that one of the reasons for reduced fatigue life under higher loading frequencies might be related to increased heat generation by hysteresis, leading to a fatigue damage mechanism governed by temperature effects. The results, thus, encourage the development of good practices regarding test frequencies in order to be able to uncouple thermal and mechanical effects and provide relevant data for structural integrity assessments.
Corresponding author. FEI University, Av. H. A. C. Branco, 3972 – office K5-09, São Bernardo do Campo, SP 09850-901, Brazil. Fax: +55 11 43532900x2051.
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http://www.sciencedirect.com/science/article/pii/S1878029611006396
