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ARTICLE
Study of the Superficial Modification of Sisal Fibres with Lignin, and Its Use As a Reinforcement Agent in Cementitious Composites
Plínio B. Mundim1, Rondinele A. R. Ferreira1, Leila A. C. Motta1, Mariana A. Henrique2, Daniel Pasquini2,*
1 College of Civil Engineering, Federal University of Uberlândia, Uberlândia, 38400-902, Brazil
2 Chemistry Institute, Federal University of Uberlândia, Uberlândia, 38400-902, Brazil
* Corresponding Authors: Daniel Pasquini. Email: ;
(This article belongs to this Special Issue: 15th Brazilian Polymer Conference (15th CBPol))
Journal of Renewable Materials 2020, 8(8), 891-903. https://doi.org/10.32604/jrm.2020.010655
Received 03 February 2020; Accepted 25 March 2020; Issue published 10 July 2020
Abstract
The objective of this work was to evaluate different superficial treatments of sisal fibres employing lignin, and their use as a reinforcement agent
in cementitious composites. The treatments consisted of superficially impregnating sisal fibres (S) with organosolv lignin (LO), organosolv lignin and glutaraldehyde (LOG), Kraft lignin (LK) and Kraft lignin and glutaraldehyde (LKG). The
fibre modifications were verified by FTIR-ATR and SEM analyzes, and the presence of lignin on the surface of the fibres was evidenced, confirming the effectiveness of the treatments. The mechanical, thermal (by TGA) and water
absorption properties of the fibres before and after the modifications were also
investigated. After treatment, the modified fibres presented an expressive reduction of the water absorption and did not show significant changes in the mechanical properties when compared with the natural unmodified sisal fibre (SNAT). It
was verified an increase in the thermal stability of the treated fibres which can be
attributed to the insertion of lignin on the fibres. To evaluate the performance of
the fibres in the cementitious composites, cement plates (CP) were produced with
different treated fibres (CP-SLOG, CP-SLO, CP-SLKG, CP-SLK) and fibres
without treatment (CP-SNAT). The composites were evaluated concerning to
the water absorption, porosity and mechanical properties. The fractured regions
were also investigated by SEM. All composites prepared showed similar values
of absorption and porosity indexes. From the mechanical properties, the composites prepared with modified fibres showed a significant increase in the modulus
of rupture and modulus of elasticity compared with CP-SNAT, while toughness
was similar to all samples. From the SEM images, it was observed that the modified fibres immersed in the cementitious plates showed no degradation, indicating
that the impregnation of lignin acted as a protective agent of the fibres. Therefore,
the treatments of the fibres with lignin led to a significant improvement in the
properties of the composites generating a treatment with potential for industrial
application.
Keywords
Cite This Article
Mundim, P. B., A., R., A., L., Henrique, M. A., Pasquini, D. (2020). Study of the Superficial Modification of Sisal Fibres with Lignin, and Its Use As a Reinforcement Agent in Cementitious Composites.
Journal of Renewable Materials, 8(8), 891–903.