| Title: SELF REINFORCED COMPOSITE OF THERMOTROPIC LIQUID CRYSTAL
POLYMERS Inventor(s): A. Isayev, P. Subramanian
Disclosure 144 U.S. Patent 5,070,157
Blend of two or more thermotropic liquid crystal polymers and process for preparing
same. Blends of this invention contain at least two, preferably only two, thermotropic
liquid crystal polymers which are melt processable. These liquid crystal polymers are
wholly aromatic polyesters. At least two polymers in the blend are processable in the melt
phase and phase separated in the solid phase. Solid reinforcing agents may be present, but
are not necessary and, in any case, must be in the solid phase at temperatures at which
the blend is melt processable. Products of this invention are formed in the melt phase
under high strain conditions.
Products of the present invention exhibit exceptional mechanical properties, including
tensile modulus, tensile strength and notched Izod impact strength; high heat resistance
and good electrical properties which remain stable over a wide range of temperatures and
frequencies. Polymer composites may be pelletized and then formed into shaped articles,
tapes, films or fibers. Polymer composites of this invention are especially suitable for
injection molding.
Composites of this invention have tensile strength comparable to those of steel on a
volume basis, and to have strengths exceeding those of aluminum on a volume basis. On a
weight basis, the composite materials of this invention are much stronger than either
steel or aluminum since the density of the new materials is about 1.4 versus about 2.7-2.8
for aluminum and approximately 7.5 for steel. This means that the novel polymer composites
of blends give light weight strong materials.
This technology is ideally suited for high performance applications such as electrical,
electronics, aerospace and automotive. Potential applications include: automotive - fuel
lines and tanks, body panels, struts, under-the-hood parts, engine parts, under-the-hood
electronics; aerospace - luggage compartment panels, floors, seat structures, bulk heads,
helicopter blades, solar concentrators, solar panels; electronics and opticals - optical
fiber jackets, interconnect devices, circuit boards, interlayer dielectrics, wire
insulation, substrates for electronic packaging; marine - boat hulls and interior panels;
medical - barrier film for packaging.
In addition, polymer composites are useful as replacements for present composite
components which are produced by sheet molding compound (SMC) technology. Products of this
invention can be produced at faster rates and with less power consumption, resulting in
lower product costs, compared to conventional composites in which fibers are prepared in
advance. |
