Abstracts Book - IMRC 2018

• SB1-O015
THE INFLUENCE OF CURE AGENT, TREATMENT AND FIBERS
CONTENT ON THE THERMAL BEHAVIOR OF A CURAUA/EPOXY
PREPREG
Vilson Dalla Libera Junior 1 , Rosineide Miranda Leão 1,2 , Sandra Maria Da Luz 1,3
1 Universidade de Brasília, Engineering Materials Integrity Program, Brazil. 2 Universidade
Paulista, Institute of Exact Sciences and Technology, Brazil. 3 University of Alberta, Department
of Chemical and Materials Engineering, Canada.
The number of researchers involved in the study of the natural fibers
prospective as load-bearing elements in composite materials has been growing
over the last few years. The plant fibers present advantages related to their
biodegradability and availability from renewable sources, contributing to a
healthier and sustainable ecosystem. In this perspective, curauá fibers are leaf
fibers extracted from an Amazon-forest plant (Ananas erectifolius) that
resembles a pineapple plant. Curauá fibers have low-cost of production and
offer a relatively high tensile strength level when applied in composites
materials. The main objective of this work is to determine the thermal behaviour
and cure parameters of a curauá fibers epoxy prepreg through Differential
Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TG-DTG). On the
way to produce the curauá/epoxy prepregs, the influence of the three main
variables of the prepreg obtainment methodology was evaluated from a
factorial design 2³. The curauá fibers were used in natura or with alkali treatment
based on the Oliveira and Luz methodology and by blanket technique. The
matrix solution was prepared at room temperature by mixing proper quantities
of DGEBA epoxy monomer and a specific hardener. The fibers blanket in a
specific weight fraction was impregnated with an epoxy matrix solution using a
manual rolling process. The prepreg cure behaviour and its glass transition
temperature (Tg) was investigated using heating heat of 5 °C/min, from room
temperature up to 300 °C under nitrogen flow. The prepreg Tg was lower with
the treated fibers than in natura. The samples with the higher portion of fibers
presented the largest degree of cure (94.05–115.8 J/g) and the peak temperature
remained constant at 119.4 °C. The neat matrix degree of cure was found to be
~58% and the weight loss of prepreg amounted to 4.68–6.67%. The
characterization of this composite is necessary to define the final prepreg
processing conditions and to evaluate the cure cycle used to manufacture
polymeric components.