Characterization Of Halogen-Free Core Material With Various Flame Retardants
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Date
2012-06
Authors
Lim, Patrick Wye Kheong
Journal Title
Journal ISSN
Volume Title
Publisher
Universiti Sains Malaysia
Abstract
The effect of three different types of halogen-free flame retardants, which are
the intumescent ammonium polyphosphates (APP), melamine cyanurate (MC) and
calcium borate (CaB) on epoxy/glass fiber composites was studied. The single and
hybrid flame retardant fillers were used to investigate the composites fire properties,
mechanical and thermal properties. In general, after decompose at 700oC, CaB leaves
behind the highest residual content, which mainly comprises of chars and glassy
substrates. This is followed by APP which decomposes and forms the chars, while
MC decomposes mainly into volatile gases. Among the three types, APP performed
the best in flame retardancy while CaB is not effective in this composite. As for the
mechanical properties of the composites, CaB gives the highest flexural strength
while MC provides the highest flexural modulus to the composites. In terms of
thermal properties, the flame retardants have lowered the thermal stability of the
composites but did not significantly affect the coefficient of thermal expansion
(CTE) and glass transition temperature (Tg). The second phase which studied on the
hybrid system, found that APP-MC and APP-CaB according to 80-20 ratio gave
synergistic effect on the fire properties to the composites. The hybrid compounds
remain at Vhigher
flexural strength, but was found not to affect the Tg and CTE. On the addition
of 0.5 vol. % metal chelates into hybrid-flame retardant system, the fire resistance
did not show any improvement in terms of their LOI values. The residual content of
the flame retardants after decomposition have also decreased. The flexural
properties, Tg and CTE were also not affected by the metal chelates.
Description
Keywords
The effect of three different types of , halogen-free flame retardants