JEC COMPOSITES MAGAZINE - Issue #134 - May/June 2020 - 64

TECHNOLOGY biocomposites

Diss grass fibre:
a new reinforcement for biocomposites

Mustapha Nouri,
PhD student
Mahfoud Tahlaiti,
Researcher : Innovative materials
Icam Nantes & GeM-Centrale Nantes
Contact: mahfoud.tahlaiti@icam.fr

The Ampelodesmos mauritanicus plant, Mauritanian grass or
also called 'Diss', is a perennial abundant plant, having attractive
characteristics for ecofriendly materials. This work aims to highlight
the potential of the Diss fibers elements by assessing their use as
reinforcement for polymer matrices (bio-composite).

D

iss grass (Figure 1) is of plant of the Poaceae family [1]. This
perennial grass, also called Ampelodesmos mauritanicus or
Mauritanian grass, can reach 2-3 metres in height. Densely fibrous and very robust, it has acuminate (pointed) leaves and grows
in clumps, in more or less dry soil [1].
The aim of this study is to demonstrate the potential of diss fibres
for use as reinforcement for polymer matrices (biocomposites). An
extraction method has been developed for the purpose. The fibres
were treated both chemically with sodium carbonate (NTFD), silane
(STFD) and acetic acid (ATFD), and thermally (TTFD), then characterized using physicochemical and mechanical analyses.
Unlike plants that contain bast fibres (like hemp and flax), diss grass
resembles miscanthus, with a stem that includes long acuminate leaves
that roll up once the plants have been harvested. Each leaf is a few

Fig. 1: Diss plant

64

jec composites magazine / N°134 May - June 2020

hundred nanometres thick. The leaves are characterized by a smooth
outer surface and a prickly, undulating inner surface (see Figure 2.a).
Observations of these leaves under optical microscope showed them
to be fibre rich.
From the exterior to the interior, the diss leaf (See Figure 2.b) is composed of a thick layer of outer epidermis; vascular bundles at the leaf's
centre surrounded by chlorenchyma (parenchyma tissue with chlorophyll); and an inner, thinner epidermal layer with spines (trichomes).
The inner portion of the leaf is filled with parenchyma cells, or "elementary fibres".

The specific morphology of the plant responsible for
industrial-scale exploitation difficulties
There is currently no extraction method dedicated to this type of
plant (including miscanthus) that would take its specific morphology into account. In general, the extraction process is informed
mechanically at the industrial scale. The absence of an extraction
technique adapted to this type of plant makes industrial-scale exploitation difficult. Merzoud and Hatiba [4] ground up diss plant to
obtain what they call diss fibres. For his thesis research, Bourahli [5]
used retting in water and sodium carbonate as dissolution method.
Sarasini et al. [6] used an enzyme method. These extraction methods
had an influence on the mechanical properties of the fibres. Bourahli
[5] found an average tensile strength for the diss fibres of 149 ± 81
MPa, while Sarasini et al. [6] found a low strength at 19 MPa.

Figure 2: Observation of the cross-section
of the diss leaf with optical microscope a) X100, b) X200 [2].
JEC COMPOSITES MAGAZINE - Issue #134 - May/June 2020

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #134 - May/June 2020
