Composite Materials Research Progress

In: Composite Materials Research Progress ISBN: 1-60021-994-2
Editor: Lucas P. Durand, pp. 129-164 © 2008 Nova Science Publishers, Inc.
Chapter 4
AN EXPERIMENTAL AND ANALYTICAL STUDY
OF UNIDIRECTIONAL CARBON FIBER REINFORCED
EPOXY MODIFIED BY SIC NANOPARTICLE
Yuanxin Zhou a , Hassan Mahfuz b , Vijaya Rangari a
and Shaik Jeelani a
a Center for Advanced Materials at Tuskegee University, Tuskegee, AL, 36088
b Department of Ocean Engineering, Florida Atlantic University, Boca Raton, FL 33431
Abstract
In the present investigation, an innovative manufacturing process was developed to
fabricate nanophased carbon prepregs used in the manufacturing of unidirectional composite
laminates. In this technique, prepregs were manufactured using solution impregnation and
filament winding methods and subsequently consolidated into laminates. Spherical silicon
carbide nanoparticles (β-SiC) were first infused in a high temperature epoxy through an
ultrasonic cavitation process. The loading of nanoparticles was 1.5% by weight of the resin.
After infusion, the nano-phased resin was used to impregnate a continuous strand of dry
carbon fiber tows in a filament winding set-up. In the next step, these nanophased prepregs
were wrapped over a cylindrical foam mandrel especially built for this purpose using a
filament winder. Once the desired thickness was achieved, the stacked prepregs were cut
along the length of the cylindrical mandrel, removed from the mandrel, and laid out open to
form a rectangular panel. The panel was then consolidated in a regular compression molding
machine. In parallel, control panels were also fabricated following similar routes without any
nanoparticle infusion. Extensive thermal and mechanical characterizations were performed to
evaluate the performances of the neat and nano-phased systems. Thermo Gravimetric Analysis
(TGA) results indicate that there is an increase in the degradation temperature (about 7 0 C) of
the nano-phased composites. Similar results from Differential Scanning Calorimetry (DSC)
and Dynamic Mechanical Analysis (DMA) tests were obtained. An improvement of about
5 0 C in glass transition temperature (T g) of nano-phased systems were also seen. Mechanical
tests on the laminates indicated improvement in flexural strength and stiffness by about 32%
and 20% respectively whereas in tensile properties there was a nominal improvement between
7-10%. Finally, micro numerical constitutive model and damage constitutive equations were
derived and an analytical approach combining the modified shear-lag model and Monte Carlo