This search aims to study the effect of additive materials ( Ethyl Methyl Keton
Peroxide MEKP , Cobalt Naphthenate ) at the important values of (stress-strain) curves
( stress and elongation at break ) for the preparing specimens from reinforced an
d nonreinforced
with fiber glass unsaturated polyester resin.
The result showed that the investigated parameters are clearly affected with using
additive materials and the optimum concentration for non-reinforced specimens which was
curing in room temperature was (1% MEKP + 1% Cobalt Naphthenate) and (0.8% MEKP
+ 1% Cobalt Naphthenate), and for reinforced specimens with fiber glass was:( 1% MEKP
+ 0.8% Cobalt Naphthenate) and ((0.2-0.4) % MEKP + 1% Cobalt Naphthenate).
The results showed also that it is possible to get the better values of tensile stress at
break when the specimens was curing in oven at 100 Cº and treated at this temperature for
15 min.