The present invention provides a polymer-based piezoelectric composite material from which a piezoelectric film capable of outputting a higher sound pressure is obtained in a case of using a piezoelectric speaker, a piezoelectric film formed of the polymer-based piezoelectric composite material, and a piezoelectric speaker and a flexible display which are formed of the piezoelectric film. The polymer-based piezoelectric composite material of the present invention is a polymer-based piezoelectric composite material including a polymer matrix which contains a polymer containing a group represented by Formula (1), and piezoelectric particles.

*-L.sup.1-CR.sup.1R.sup.2—CN  Formula (1) In Formula (1), L.sup.1 represents a divalent linking group excluding a divalent aliphatic hydrocarbon group. R.sup.1 and R.sup.2 each independently represent a hydrogen atom, an alkyl group, or an aryl group.

The invention relates to a curable fluoroelastomer composition having low swelling tendency, comprising: A) a curable fluoroelastomer; B) a curing system; and C) 0.1 wt.-% to 30 wt.-% of a nitrogen-containing polymer, selected from polyamide, polyimide, mixtures and/or copolymers thereof, each relative to the total weight of fluoroelastomer and nitrogen-containing polymer, the nitrogen-containing polymer being present in particulate form of an average particle size in the range of 0.15 to 70 μm and/or in fiber form having an average fiber diameter in the range of 0.15 to 70 μm.

The invention pertains to certain fluoroelastomer compositions including given amounts of certain aromatic polyamide-imide polymers, having ability to adhere upon curing to various substrates, to a process for their manufacture, to a method for fabricating shaped articles comprising curing the said compositions, to cured articles therefrom, and to assemblies including a substrate and said cured articles.

Flexible substrates including a polymer selected from a thermoplastic polymer, a thermoset polymer, and/or a polymer blend, and ferroelectric perovskite-type oxide particles dispersed in the polymer, where the ferroelectric perovskite-type oxide has a dielectric constant that varies with applied voltage. The flexible substrates can be used in tunable electronics.

The disclosure provides a composite for forming an insulating substrate. The composite includes 100 parts by weight of a modified liquid crystal polymer and 0.5-85 parts by weight of a dielectric additive. The modified liquid crystal polymer has a repeating unit represented by

##STR00001##

in which Ar is 1,4-phenylene, 1,3-phenylene, 2,6-naphthalene, or 4,4-biphenylene, Y is O or NH, and X is carboxamido, imido/imino, am idino, aminocarbonylamino, aminothiocarbonyl, aminocarbonyloxy, aminosulfonyl, aminosulfonyloxy, aminosulfonylamino, carboxyl ester, (carboxyl ester)amino, (alkoxycarbonyl)oxy, alkoxycarbonyl, hydroxyamino, alkoxyamino, cyanato, isocyanato, or a combination thereof.

The invention relates to a curable fluoroelastomer composition having low swelling tendency, comprising: A) a curable fluoroelastomer; B) a curing system; and C) 0.1 wt.-% to 30 wt.-% of a nitrogen-containing polymer, selected from polyimide, polyimide, mixtures and/or copolymers thereof, each relative to the total weight of fluoroelastomer and nitrogen-containing polymer, the nitrogen-containing polymer being present in particulate form of an average particle size in the range of 0.15 to 70 ?m and/or in fiber form having an average fiber diameter in the range of 0.15 to 70 ?m.

The present invention discloses a rubber composition. The rubber composition includes a rubber matrix and a crosslinking system. The rubber matrix includes, in parts by weight, the following components: a branched polyethylene with a content represented as A, in which 0<A100, an EPM with a content represented as B, in which 0B<100, and an EPDM with a content represented as C, in which 0C<100. Based on 100 parts by weight of said rubber matrix, the content of the crosslinking system is represented as D: 1D15 parts. The crosslinking system includes at least one of a crosslinking agent and an auxiliary crosslinking agent. The branched polyethylene has a degree of branching of not less than 50 branches/1000 carbon atoms, a weight average molecular weight of not less than 50,000, and a Mooney viscosity ML(1+4) at 125 C. of not less than 2. The rubber composition provided by the present invention can effectively solve the problems of low crosslinking efficiency and mechanical strength in the prior art, and simultaneously has good electrical insulation properties and mechanical strength.

Flexible substrates including a polymer selected from a thermoplastic polymer, a thermoset polymer, and/or a polymer blend, and ferroelectric perovskite-type oxide particles dispersed in the polymer, where the ferroelectric perovskite-type oxide has a dielectric constant that varies with applied voltage. The flexible substrates can be used in tunable electronics.

The present invention discloses a rubber composition. The rubber composition includes a rubber matrix and a crosslinking system. The rubber matrix includes, in parts by weight, the following components: a branched polyethylene with a content represented as A, in which 0<A100, an EPM with a content represented as B, in which 0B<100, and an EPDM with a content represented as C, in which 0C<100. Based on 100 parts by weight of said rubber matrix, the content of the crosslinking system is represented as D: 1D15 parts. The crosslinking system includes at least one of a crosslinking agent and an auxiliary crosslinking agent. The branched polyethylene has a degree of branching of not less than 50 branches/1000 carbon atoms, a weight average molecular weight of not less than 50,000, and a Mooney viscosity ML(1+4) at 125 C. of not less than 2. The rubber composition provided by the present invention can effectively solve the problems of low crosslinking efficiency and mechanical strength in the prior art, and simultaneously has good electrical insulation properties and mechanical strength.

Parts made by additive manufacturing are often structural in nature, rather than having functional properties conveyed by a polymer or other component present therein. Printed parts having piezoelectric properties may be formed using compositions comprising a plurality of piezoelectric particles dispersed in at least a portion of a polymer matrix comprising first polymer material and a sacrificial material, the sacrificial material being removable from the polymer matrix to define a plurality of pores in the polymer matrix. The piezoelectric particles may remain substantially non-agglomerated when combined with the polymer matrix. The sacrificial material may comprise a second polymer material. The compositions may define a composite having a form factor such as a composite filament, a composite pellet, a composite powder, or a composite paste. Additive manufacturing processes may comprise forming a printed part by depositing the compositions layer-by-layer and introducing porosity therein.