Wheat gluten composites reinforced with coconut fiber

Published Date
July 2012, Vol.43(7):1160–1168, doi:10.1016/j.compositesa.2012.02.011

Author 

Sudsiri Hemsri ^a

Kasia Grieco ^a

Alexandru D. Asandei ^b,c

Richard S. Parnas ^a,b,,

• aDepartment of Chemical, Materials and Biomolecular Engineering, University of Connecticut, 191 Auditorium Road, Unit 3222, Storrs, CT 06269-3222, USA
• bInstitute of Materials Science, University of Connecticut, 97 North Eagleville Road, Storrs, CT 06269-3136, USA
• cDepartment of Chemistry, University of Connecticut, 55 North Eagleville Road, Unit 3060, Storrs, CT 06269-3060, USA

Received 5 December 2011. Revised 19 February 2012. Accepted 20 February 2012. Available online 28 February 2012.

Abstract

Coconut fiber-reinforced wheat gluten (WG) biocomposites were fabricated. The coconut fibers (CCFs) were chemically modified by either sodium hydroxide or silane treatment, as well as following the alkali surface treatment with a silane treatment. (3-triethoxysilylpropyl)-t-butylcarbamate (carbamate silane), which is a masked isocyanate functional silane, was used for the first time to improve interfacial adhesion between WG and natural fibers. X-ray photoelectron spectroscopy (XPS) and gas chromatography/mass spectroscopy (GC/MS) analyses were employed to prove the presence of the silane on silane-treated coconut fiber (SCCF) and alkali-followed by silane-treated fiber (ASCCF). It was found that ASCCF has more silane content on the fiber surface than SCCF. The mechanical properties of composites with 15 mass% fiber loading were assessed by three-point bending tests. Moreover, scanning electron microscopy (SEM) was used to investigate fracture surface characteristics of composites. The WG/ASCCF composite provided an 80% increase in strength, and showed superior fiber–matrix interfacial adhesion.

Keywords

A. Natural fibre composites

D. Surface analysis

A. Biopolymer composite

B. Mechanical properties

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• ⁎ 
  Corresponding author at: Institute of Materials Science, University of Connecticut, 97 North Eagleville Road, Storrs, CT 06269-3136, USA. Tel.: +1 860 486 9060; fax: +1 860 486 4745.
  
  

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Studies on lignocellulosic fibers of Brazil. Part II: Morphology and properties of Brazilian coconut fibers

Published Date
July 2007, Vol.38(7):1710–1721, doi:10.1016/j.compositesa.2007.02.004

Author 

Fábio Tomczak ^a

Thais Helena Demétrio Sydenstricker ^b

Kestur Gundappa Satyanarayana ^c,,

• aKlabin Papéis Monte Alegre, Fazenda Monte Alegre – Harmonia, Telêmaco Borba, Paraná, Brazil
• bDepartment of Mechanical Engineering, Federal University of Parana (UFPR), Centro Politecnico, Jardim das Americas, P.B. No. 19011, CEP: 81531-980, Curitiba, PR, Brazil
• cDepartment of Chemistry, Federal University of Parana (UFPR), Centro Politecnico, Jardim das Americas, P.B. No. 19081, CEP: 81531-990, Curitiba, PR, Brazil

Received 1 June 2006. Revised 12 February 2007. Accepted 13 February 2007. Available online 20 February 2007.

Abstract

Stress–strain curves for different diameters, tensile properties and thermal behaviour of Brazilian coir fibers are presented. The tensile strength (TS) and Young’s modulus (YM) of these coir fibers were found to decrease, while the percentage (%) strain at break remained constant as fiber diameter increased. With fibers (mean diameter of 0.225 mm), a decrease in TS and % strain at break but an increase in YM with increasing test length of the fiber, and a considerable increase in TS, constant YM and % strain at break with increasing strain rate were observed. The results are discussed in terms of X-ray diffraction and microscopic observations. Thermal behaviour of the fibers revealed degradation of different constituents in an N₂ or O₂atmosphere. Thermo-mechanical analysis of the fibers revealed increased modulus and decreased tan δ values.

Keywords

A. Coconut fiber

B. Tensile properties

B. Thermal analysis

D. Microstructure

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Tensile behaviours of the coir fibre and related composites after NaOH treatment

Published Date
October 2009, Vol.30(9):3931–3934, doi:10.1016/j.matdes.2009.01.035

Short Communication

Author 

Huang Gu ^,

• School of Textiles, Tianjin Polytechnic University, 63 Chenglin Road, Hedong District, Tianjin 300160, PR China

Received 7 November 2008. Accepted 30 January 2009. Available online 5 February 2009.

Abstract

Brown coir fibres were treated by NaOH solution with concentrations from 2% to 10% separately. Tensile strength of the alkali-treated fibres was measured. A decreased trend of the fibre tensile strength with increased NaOH density was found.

Laminated coir fibre net was used as the reinforcement and polypropylene as the matrix to fabricate the composites with a heat press. The tensile strength of the samples was shown.

In the case of NaOH density with 10%, lower tensile strength of the composite was noticed compared to the cases of 2%, 4%, 6% and 8%. This demonstrated that the fibre deterioration in the 10% case was serious.

No significant difference was revealed in the composite tensile strength among the cases of 2%, 4%, 6% and 8%. This implied that the improved adhesive ability of the coir fibre with the matrix after the alkali treatment had been outweighed by the strength loss of the fibre in these four cases.

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Effect of lignin removal on the properties of coconut coir fiber/wheat gluten biocomposite

Published Date
February 2011, Vol.42(2):173–179, doi:10.1016/j.compositesa.2010.11.002

Author 

Pakanita Muensri ^a

Thiranan Kunanopparat ^b,,

Paul Menut ^c

Suwit Siriwattanayotin ^a

• aDepartment of Food Engineering, Faculty of Engineering, King Mongkut’s University of Technology Thonburi, Tungkru, Bangkok 10140, Thailand
• bPilot Plant Development and Training Institute, King Mongkut’s University of Technology Thonburi, Tungkru, Bangkok 10140, Thailand
• cUMR 1208 Ingénierie des Agropolymères et Technologies Emergentes, INRA, CIRAD, Montpellier SupAgro, Université Montpellier 2, F-34000 Montpellier, France

Received 2 June 2010. Revised 17 September 2010. Accepted 3 November 2010. Available online 6 November 2010.

Abstract

The effect of fiber lignin content on biocomposite properties was investigated. Coconut fiber was treated with 0.7% sodium chlorite to selectively decrease amounts of lignin. The fiber lignin content was then reduced from 42 to 21 wt.%. The composition and mechanical properties of the individual modified fibers were characterized. Gluten-based materials reinforced with modified fibers were prepared by compression molding. Then, the mechanical properties, water sensibility, matrix glass transition and infrared spectra of biocomposites prepared with fibers containing various amounts of lignin were evaluated. This study showed that the addition of coconut coir fiber significantly improved properties of wheat gluten biomaterials. In addition, the variation of lignin content in the fibers, in the investigated range, had no significant effect neither on matrix deplasticization nor fiber/matrix adhesion, suggesting that a partial lignin removal is not an efficient way to improve the properties of natural fiber/plasticized protein biocomposites.

Keywords

• A. Fibers
• B. Adhesion
• B. Mechanical properties

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