Volume 10,
Issue 5, 2001
THE
EFFECT OF TRANSCRYSTALLINITY ON THE INTERFACE OF GREEN FLAX/polypropylene
COMPOSITE MATERIALS
N.
E. Zafeiropoulos1,2,* , C. A. Baillie1 and F.
L. Matthews1
1Centre
for Composite Materials and Materials Department, Imperial College of
Science, Technology and Medicine, Prince Consort Road, London SW7 2AZ, UK
2Current
address: Institut fόr Polymerforschung e.V., Hohe Straίe 6,
01069 Dresden, Germany, e-mail: zafeiropoulos@ipfdd.de
*Author to whom
correspondence should be addressed
(Received 8/01;
accepted 10/01)
Abstract
In recent years there has
been an increasing interest in using natural fibres as potential
reinforcements for polymers. The introduction of fibres such as flax in
a semicrystalline thermoplastic matrix such as iPP (isotactic
polypropylene) has been shown to lead to the development of
transcrystallinity. The presence of an anisotropic layer such as
transcrystallinity in the composite material may in turn have a profound
effect on the mechanical behaviour of the interface. In this study the
role of transcrystallinity has been investigated in green flax (that is
flax as received direct from the crops)/iPP by means of the
fragmentation test. The results are discussed in terms of previously
reported results for treated flax fibres (dew retted)/iPP.
Transcrystallinity leads to a stronger interface in green flax/iPP, and
its thickness affects the interfacial strength, with thinner
transcrystalline layers giving a stronger interface. An examination of
the mode of failure at the interface after the fragmentation test also
supports the conclusion that the transcrystalline interface is stronger
than the spherulitic interface in green flax/iPP composites.
|
