摘要:
A low temperature curing polymeric adhesive composition may be made by reacting an amino alcohol having between 1 and 3 amino groups and between 2 and 5 hydroxyl groups with a stoichiometric amount of a carboxylic acid or derivative. Free radical catalysts and accelerators may be added to speed the cure of the adhesive. These adhesive resins can be cured at or near ambient room temperature and are highly desired for fabrication of bonded materials possessing long fatigue life because of reduced stresses that might be induced at higher cure temperatures. A generalized formula may be illustrated as follows: ##EQU1## WHERE R" may be hydrogen, alkyl, or cycloalkyl; R' may be hydrogen or alkyl; R is an alkyl; R.sub.1 may be hydrogen, an alkyl, or phenyl; m is an integer from 1 to 3; and n is an integer from 1 to 2.
摘要:
A compliant polyimide having superior thermal-mechanical properties can be produced by reacting an aromatic bis(furfurylimide) with an aliphatic ether bis(maleimide) via a Diels-Alder reaction. These polyimides display a long-term thermal-oxidative stability and a high percent recoverable elongation to break, and they are suitable for use as films, fibers, coatings, adhesives, structures, and sealants.
摘要:
Polyimide prepolymers formed by thermo-reactions of an aliphatic bismaleimide, where the aliphatic group is a polyaliphatic ether, with an aromatic bismaleimide and/or an aromatic diamine in combination with a trismaleimide which are curable upon addition of an acid catalyst and/or heating to about 65.degree. C.
摘要:
End-capping an aromatic diamine or a precursor formed by reaction of an aromatic diamine with an aromatic dianhydride with difluoromaleic anhydride yields prepolymers which thermally cure at temperatures from about 150.degree. to about 200.degree. C. to form polymers which display long-term thermal stability at temperatures up to 300.degree. C. and more.
摘要:
Polyimide prepolymers formed by thermo-reactions of an aliphatic bismaleimide, where the aliphatic group is a polyaliphatic ether, with an aromatic bismaleimide and/or an aromatic diamine in combination with a cross-linking agent having at least two vinyl groups provide compositions which are curable at low temperatures, i.e., 65.degree. C. or less.
摘要:
Vinyl polybutadiene maleimide prepolymers which are peroxide curable are provided. The prepolymers are formed from the reaction product of a vinyl polybutadiene providing pendant vinyl groups and a maleimide and, more particularly, a mixture of aliphatic maleimides with cycloaliphatic or aromatic maleimides in combination with a peroxide-free radical initiator. The prepolymer is a vinyl polybutadiene backbone structure having grafted maleimide polymers forming cross-linking between polybutadiene backbone segments. The resultant prepolymer can be subsequently cured to a hard resin by heating in the presence of a peroxide-free radical initiator to form cross-linking between vinyl polybutadiene structures through the pendant vinyl groups. The resultant hard resin provides strength retention at elevated temperatures and exhibits a flexibility and strength without being brittle.
摘要:
Structurally stronger titanium articles are produced by a weld-bonding technique comprising fastening at least two plates of titanium together using spot-welding and applying a bead of adhesive along the edge of the resistance spot-welded joint which, upon heating, flows and fills the separation between the joint components.
摘要:
A collapsible bulk material container apparatus, kit and method of assembly employ a forming member having a plurality of interconnected sidewalls, a locking mechanism that fixedly orients the sidewalls continuously about an internal bulk material receiving cavity, and a tubular open-ended woven fabric sleeve that supportively overlies the sidewalls. A connector system rapidly engageable during container assembly, fixedly secures the support sleeve of an unloaded container against subsequent upward movement along the sidewalls. Strategically located friction reducing surfaces of the forming member facilitates sliding assembly of the sleeve over the forming member sidewalls.
摘要:
An apparatus and method is provided relating to artificial discs. An artificial disc is provided that facilitates simultaneous and independent articulation of flexion/extension, lateral bending, anterior/posterior translation, and axial rotation. The artificial disc provides these four simultaneous and independent articulations by independently addressing each type of articulation in the design of the artificial disc. In one example, an artificial disc is comprised of a bearing disposed between first and second end plates. The bearing is movable relative to each end plate, independent of the other end plate. The end plates are affixed to adjacent vertebrae.
摘要:
An interbody fusion device for fusion of vertebrae, and methods thereof. The device includes a first piece made of titanium having upper and lower surfaces configured to engage the endplates of two opposing vertebrae. The upper and lower surfaces include a plurality of barbed teeth configured to engage an endplate. The first piece includes an inner void area configured to receive a second piece. The second piece is configured to engage the first piece to slide over inner surfaces of the first piece become seated and mated in the first piece. The first and second pieces mate to form an assembled interbody fusion device that fits between two vertebrae.