Received: 5 October 2017 Revised: 6 December 2017 Accepted article published: 21 December 2017 Published online in Wiley Online Library: 22 February 2018
(wileyonlinelibrary.com) DOI 10.1002/pi.5522
The eﬀect of ﬁbre sizing and compatibilizer of
blends on the mechanical and interphase
properties of basalt ﬁbre reinforced
and Miroslawa El Fray
The eﬀect of basalt ﬁbre sizing on the mechanical and interphase properties of ﬁbre-reinforced composites was studied. Two
diﬀerent chemical preparations of the ﬁbre surface (PBT-compliant and PP-compliant) were used. The polymer matrix was
prepared from polypropylene/poly(butylene terephthalate) (PP/PBT) immiscible polymer blend and the eﬀect of diﬀerent
compatibilizers on the composite properties was evaluated. SEM hints at improved ﬁbre adhesion to the polymer matrix when a
PP-compliant sizing is applied. SEM also reveals improved compatibilization eﬀects when block copolymer instead of multiblock
copolymer is used for the PP/PBT blend preparation. The pull-out test was applied to quantitatively evaluate the interface
adhesion between the ﬁbres and matrices. It showed a high value of the interfacial shear strength between basalt ﬁbres modiﬁed
with PP-compliant sizing and polymer blend compatibilized by block copolymer, thus conﬁrming good adhesion. One possible
explanation of such good mechanical properties can be related to the chemical interactions between functional groups, mainly
maleic anhydride on basalt ﬁbres and the polyoleﬁn component (PP) of the polymer matrix.
© 2017 Society of Chemical Industry
Keywords: polymer composites; mechanical properties; reinforcements
Glass ﬁbre reinforced thermoplastic composites draw great atten-
tion in many ﬁelds due to their good thermal and mechanical
ical properties are often signiﬁcantly improved; however, diﬀerent
factors such as ﬁbre length and concentration as well as the level
of the ﬁbre−matrix interface adhesion
play key roles in achiev-
ing high performance. To obtain good ﬁbre−matrix adhesion,
ﬁbre sizings (coatings) and surface treatments are often applied.
This solution has been adopted for silane-treated glass ﬁbre and
the maleic anhydride modiﬁed polypropylene (PP) composites.
Over the years, a great deal of research has been dedicated to ﬁnd-
ing suitable and accurate techniques to assess the ﬁbre−matrix
adhesion. These methods have been thoroughly reviewed.
The combination of two or more polymers results in blend
systems oﬀering interesting and unique properties, also from a
composites science point of view.
However, the miscibility of
polymer blends is often non-trivial,
because blends prepared
from two immiscible polymers may demonstrate lack of inter-
facial interactions and in such a case the need arises for com-
patibilization between the polymers. Compatibilized polymeric
blends exhibit improved mechanical properties, such as impact
strength and modulus.
The compatibilization process requires
reactive molecules, such as maleic anhydride, vinyl monomers,
and itaconic and methacrylic copolymers containing reactive
Other systems include thermoplastic elas-
tomers, in which two thermodynamically immiscible phases result
in nanoscopic matrix-domain morphology with a discrete thermo-
plastic (rigid) phase embedded in a continuous (soft) amorphous
matrix. The degree of phase separation, phase mixing and crys-
tallinity can be tuned via changes in the rigid to soft segment ratio
of such thermoplastic elastomers, as well as the microchain archi-
tecture (block versus multiblock copolymers).
Interface properties play a key role in composite performance.
The interfacial shear strength (IFSS) is an important parameter
reﬂecting the degree of adhesion at the ﬁbre−matrix interface. In
general, a very strong and stiﬀ interface tends to reduce the tough-
ness of composites. On the other hand, a lack of interactions in
the interfacial region will reduce the composite interlaminar shear
shear and oﬀ-axis strength, compression strength,
and hygrothermal resistance.
Correspondence to: M El Fray, West Pomeranian University of Technology,
Szczecin, Faculty of Chemical Technology and Engineering, Polymer Institute,
Al. Piastow 45, 71-311 Szczecin, Poland. E-mail: firstname.lastname@example.org
a West Pomeranian University of Technology, Szczecin, Faculty of Chemical Tech-
nology and Engineering, Polymer Institute, Szczecin, Poland
b Department of Materials and Interfaces, Weizmann Institute of Science,
Polym Int 2018; 67: 414–421 www.soci.org © 2017 Society of Chemical Industry