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Abstract:
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Block copolymers of unsaturated polyester
were prepared by condensation polymerization of hydroxyl
or carboxyl terminated liquid rubbers with maleic anhydride,
phthalic anhydride, and propylene glycol. The condensate
obtained was mixed with styrene monomer to get
an unsaturated polyester resin formulation. In this study,
copolymers of unsaturated polyesters with hydroxy terminated
polybutadiene, carboxy terminated nitrile rubber, and
hydroxy terminated natural rubber were prepared. Mechanical
properties such as tensile strength, tensile modulus,
elongation at break, toughness, impact strength, surface
hardness, abrasion resistance, and water absorption were
evaluated after the resin was cured in appropriate molds for
comparison with the control resin. The fracture toughness
and impact resistance of CTBN-modified unsaturated polyester
show substantial improvement by this copolymerization
without seriously affecting any other property |