摘要:
Curable fluoroelastomer compositions having improved compression set after curing are provided, as well as compositions that are of relatively high purity. These compositions include a hydrogen-containing fluoroelastomer having interpolymerized units derived from a cure-site monomer, a curative (optionally with a co-agent), and an organo-onium. When the fluoroelastomer contains units derived from vinylidene fluoride, the composition is essentially free from an inorganic acid acceptor. Methods of improving the compression of cured fluoroelastomer and cured fluoroelastomers having improved compression set are also provided.
摘要:
A fluoropolymer composition is provided. The polymer comprises interpolymerized units derived from (i) tetrafluoroethylene, (ii) vinylidene fluoride, (iii) at least one ethylenically unsaturated monomer of the formula CF2═CFRf where Rf is a perfluoroalkyl or a perfluoroalkoxy of 1 to 8 carbon atoms, and (iv) a perfluorovinyl ether of the formula CF2═CF—(OCF2CF(Rf))aOR′f where Rf is as described in (iii), R′f is a perfluoroaliphatic, preferably a perfluoroalkyl or a perfluoroalkoxy, of 1 to 8, preferably 1 to 3, carbon atoms, and a has a value of 0 to 3.
摘要:
A polymer processing aid composition, a melt processable polymer composition that uses the polymer processing aid, and a method of improving the melt processability of a thermoplastic polymer are provided. The polymer processing aid composition comprises a fluoropolymer that comprises interpolymerized units derived from a perfluorovinyl ether, preferably one having the formula CF2═CF—(OCF2CF(CF3))AORf where a has a value of 0 to 3 and Rf is a perfluoroaliphatic (preferably perfluoroalkyl or perfluoroalkoxy) having from 1 to 8 (preferably 1 to 3) carbon atoms.
摘要:
Non-free flowable, non-dusting molding powders with a bulk density of more than 450 g/l are obtained when a suspension polymer of tetrafluoroethylene with a content of 0.01 to 1% by weight of units of at least one perfluoro(alkyl-vinyl) ether is ground to a particle diameter of 10 to 50 .mu.m and agglomerated in water.
摘要:
Labile end groups in fluorinated thermoplastics, in particular carboxyl and acid fluoride groups, are converted into carboxamide groups when the polymer is treated with an aqueous, ammonia-containing solution. The after-treated products have a pale color, do not cause corrosion during processing and can easily be taken from the molds in transfer molding.
摘要:
A trifluoroacrylate has been prepared by reacting hexafluoropropene with halogen fluorosulfate (halogen X:Cl, Br or I), eliminating the fluorosulfate CF.sub.3 --CFX--CF.sub.2 --OSO.sub.2 F to give the acid fluoride CF.sub.3 --CFX--COF, esterifying the acid fluoride and dehalogenating the product using a metal component.
摘要:
Provided are a tetrafluoroethylene copolymers having a melting point of at least 317° C., a melt flow index (MFI) at 372° C. and a 5 kg load (MFI 372/5) of from about 0.60 g/10 min up to about 15 g/10 min. Also provided are methods of forming a shaped article using the copolymers described above, shaped articles made with those copolymers and compositions containing such copolymers.
摘要:
A composition comprising a first fluoropolymer and a second fluoropolymer. The first and second fluoropolymers are melt-processable, thermoplastic and have a melting point between 100° C. and 320° C. The first fluoropolymer has a relaxation exponent of from 0.93 to 1.0. The second fluoropolymer has a relaxation exponent of from 0.3 to 0.92. A composition comprising a first fluoropolymer having a long chain branching index of from 0 to 0.1 and a second fluoropolymer having a long chain branching index of at least 0.2. A composition comprising a core-shell polymer having a first polymer portion, wherein a polymer having an identical chemical structure as the first polymer portion has a relaxation exponent of from 0.93 to 1.0, and a second fluoropolymer portion, wherein a polymer having an identical chemical structure as the second fluoropolymer portion has a relaxation exponent of from 0.3 to 0.92. Methods for making compositions and methods of making articles from compositions.
摘要:
Provided are methods of bonding a fluoroelastomer to a metal substrate; fluoropolymer compounds comprising a fluoroelastomer, a curing agent and a bonding promoter; and composite materials obtained by curing the compound. Further provided is the use of bonding promoters for increasing the bond strength between a fluoroelastomer and a metal substrate.
摘要:
A composition including at least one first divalent unit represented by formula: Each Rf is independently selected from the group consisting of Rfa—(O)t—CHF—(CF2)n—; [Rfa—(O)t—C(L)H—CF2—O]m—W—; Rfb-O—(CF2)p-; F(CkF2k)—(O—CkF2k)P—O—CF2—; and CF3—O—(CF2)3—(OCF(CF3)—CF2)Z—O-L1-. Each Q is independently selected from the group consisting of a bond, —C(O)—N(R1)—, and —C(O)—O—. Each X is independently selected from the group consisting of alkylene and arylalkylene, wherein alkylene and arylalkylene are each optionally interrupted by at least one ether linkage and optionally terminated by —N(R1)—C(O)— or —O—C(O)—. R and R1 are each independently selected from the group consisting of hydrogen and alkyl having from 1 to 4 carbon atoms. Rfa represents a partially or fully fluorinated alkyl group having from 1 to 10 carbon atoms and optionally interrupted with at least one oxygen atom. Rfb is selected from the group consisting of CF3CFH— and F(CjF2j)-. Methods of reducing surface tension of a liquid, making foams, and treating a surface using the compositions are also disclosed.