Elsevier

Materials & Design

Volume 32, Issue 1, January 2011, Pages 453-461
Materials & Design

Technical Report
Microstructural, physico-chemical and mechanical characterisation of Sansevieria cylindrica fibres – An exploratory investigation

https://doi.org/10.1016/j.matdes.2010.06.004Get rights and content

Abstract

The microstructural, physical, chemical and mechanical properties of Sansevieria cylindrica fibres are described for the first time in this work. A microstructural analysis of S. cylindrica leaves showed the presence of structural fibres and arch fibres. Polarised light microscopy and scanning electron microscopy of these fibres revealed a hierarchical cell structure that consisted of a primary wall, a secondary wall, a fibre lumen and middle lamellae. The cross-sectional area and porosity fraction of the fibre were estimated to be approximately 0.0245 mm2 and 37%, respectively. The fibre density and fineness were approximately 0.915 ± 0.005 g/cm3 and 9 Tex, respectively. An X-ray diffraction and Fourier transform infrared analysis of the fibres showed the presence of cellulose Iβ with a crystallinity index of 60%. Tensile tests showed that the corrected Young’s modulus was approximately 7 GPa, the tensile strength was 658 MPa, and the total elongation was between 10% and 12%.

Introduction

Environmental awareness groups all over the world have focused their attention on the use of cellulose fibres to reinforce polymer matrixes. The attractive features of natural fibres include their low cost, light-weight, moderate strength, high specific modulus, renewability, biodegradability, lack of health hazards and amenability to chemical modification. Therefore, natural fibre-based composites have good potential for use as building materials. Several authors have reported the use of natural fibres such as palmyra [1], sisal [2], banana [3], oil palm [4], henequen [5], jute [6], hemp [7] and wood pulp [8] as reinforcements in polymer matrixes.

The industrial use of natural fibres as reinforcements in composite materials started at the beginning of the 20th century with the manufacturing of large quantities of sheets, tubes and pipes for electronic purposes. For example, the seats and fuel tanks of aircraft were made of natural fibres with a small content of polymeric binders [9]. When cost-effective synthetic fibres that were less sensitive to temperature and moisture were brought onto the market, natural fibres were largely abandoned in these industries. More recently, stringent environmental regulations and an increased interest in the use of natural resources have led to a positive change among composite industries and end users. Efforts are being made to find alternate reinforcements and resin systems that are eco-friendly and provide the same performance as their synthetic counterparts [10].

Today, a revolution in the use of natural fibres as reinforcements in technical applications is taking place, primarily in the automotive industry. European renewable fibres such as flax and hemp are now used to manufacture door panels and the roofs of automobiles [10]. However, accelerating the substitution of synthetic fibres by natural fibres requires the greater availability of such fibres, and their current production level does not meet today’s demand. New plants must be found that enable easy and cost-effective extraction methods that do not impair the properties of the fibre. These new fibres must be analysed to determine their physical, chemical and mechanical properties. Microscopy (either optical or electron) is an invaluable tool to strengthen our knowledge of the morphology of fibres. This knowledge is essential to evaluate or efficiently simulate the properties of these fibres.

In this paper, the Sansevieria cylindrica and fibres extracted from it are described. The present study aims to investigate the potential use of S. cylindrica fibres (SCFs) as reinforcements in polymeric materials. The physical, chemical and mechanical properties of the SCFs were measured and compared with other natural fibres. A pycnometer was used to assess the density of the fibres, and a chemical analysis was performed to determine their lignin, cellulose, hemicellulose, wax and moisture content. The chemical analysis of the SCF was fine tuned using X-ray diffraction (XRD) and Fourier transform infrared (FTIR) analysis. A microscopic examination was carried out with a polarised light microscope and a scanning electron microscope (SEM). The tensile properties of the fibre were measured using an INSTRON universal testing machine.

Section snippets

Natural fibre material

Plants of S. cylindrica Wenceslas Bojer [11], belongs to Ruscaceae were collected from Papanasam in Western Ghats, Tamil Nadu, South India, and established in a home garden at Vickramasingapuram in Tamil Nadu, India. This plant was used to obtain the natural fibres.

Preparation of specimens and sectioning

Healthy S. cylindrica leaf was collected for microstructural analysis. For anatomical studies, the leaf was cut into small pieces (10 mm × 10 mm) and fixed in FAA (5 ml formaldehyde + 5 ml acetic acid + 90 ml 70% ethyl alcohol). After 24 h, the specimens were dehydrated through a graded tertiary-butyl alcohol series and embedded in paraffin [13]. Sections of 10–12 μm were cut on a rotary microtome, affixed to a glass slide and stained with a mixture of Toluidine blue, safranine, fast green and Lugo’s iodine

Microstructural analysis of S. cylindrica leaf and fibres

In the transverse sections, the leaf displayed a dermal tissue system, a ground tissue system and a vascular tissue system.

The dermal tissue consisted of a well-defined epidermis with radially oblong, fairly wide cells that have thick cuticles (see Fig. 6a). The epidermal layer had cuticles that were 70 μm thick. The ground tissue was homogeneous and parenchymatous. The cells were circular to polygonal, thin walled and compact. Fibre bundles were observed in the ground tissue (Fig. 6a). The

Conclusions

Four major conclusions were drawn from the test results. First, the polarised light micrograph and SEM investigations revealed that S. cylindrica leaves contain two types of fibres: structural fibres and arch fibres. The microstructural analysis of SCFs showed the presence of primary cell walls, secondary cell walls, fibre lumens and middle lamellae. Second, the average cross-sectional area of one of these fibres is 0.0245 mm2. The average density and porosity fraction of the SCF is 0.915 ± 0.005 

Acknowledgments

The authors thank the management of Dr. Sivanthi Aditanar College of Engineering, Tiruchendur 628 215, Tamil Nadu, India, for providing necessary assistance to carry out this research.

References (39)

  • R.G. Elenga et al.

    On the microstructure and physical properties of untreated raffia textilis fiber

    Compos Part A

    (2009)
  • K. Subramanian et al.

    Characterization of lignocellulosic seed fiber from Wrightia tinctoria plant for textile applications an exploratory investigation

    Eur Polymer J

    (2005)
  • A.M. Hindeleh et al.

    An empirical estimation of Scherrer parameters for the estimation of the crystallite size in fibrous polymers

    Polymer

    (1980)
  • A. Ishikawa et al.

    Fine structure and tensile properties of ramies in the crystalline form of cellulose I, II, III and IV

    Polymer

    (1997)
  • S.Y. Oh et al.

    Crystalline structure analysis of cellulose treated with sodium hydroxide and carbon dioxide by means of X-ray diffraction and FTIR spectroscopy

    Carbohydr Res

    (2005)
  • R.G. Zhbankov et al.

    Structural physico-chemistry of cellulose macromolecules. Vibrational spectra and structures of cellulose

    J Mol Struct

    (2002)
  • V. Manikandan et al.

    Mechanical properties of short and unidirectional aligned Palmyra fiber reinforced polyester composite

    Int J Plast Technol

    (2004)
  • A. Poothan Laley et al.

    Polarity parameters and dynamic mechanical behavior of chemically modified banana fiber polyester composites

    Compos Sci Technol

    (2003)
  • M.S. Sreekala et al.

    Utilization of short oil palm empty fruit bunch as reinforcement in phenol formaldehyde resin

    J Polym Eng

    (1996)
  • Cited by (284)

    View all citing articles on Scopus
    View full text