摘要:
The present invention describes a novel process for the preparation of perfluoro allyl ethers. The process involves providing a hydrogen-containing precursor comprising at least one 1,2-dichloro alkyl ether moiety, fluorinating the precursor to provide a perfluorinated intermediate, and dechlorinating the perfluorinated intermediate to the corresponding perfluorinated ether. A reaction product of a perfluorinated olefin and an allyl ether may also be used as a precursor. Such a reaction product is chlorinated before the fluorination step. Perfluoro vinyl or allyl ethers may be used in place of the perfluorinated olefin. Novel perfluoro alkoxy compounds are also described.
摘要:
The present invention describes a novel process for the preparation of perfluorovinyl ethers. The process involves providing a hydrocarbon precursor that may be partially halogenated, fluorinating the precursor to provide a perfluorinated intermediate, and converting the perfluorinated intermediate to the desired perfluorinated ether. Novel perfluorovinyl ethers are also provided.
摘要:
A method of making a curable fluoroelastomer is disclosed. The method comprises the steps of preemulsifying at least one perfluorovinylether in water, and copolymerizing the preemulsified perfluorovinylether with a gaseous fluorinated monomer in the presence of a cure site monomer. The method provides a fluoroelastomer having a glass transition temperature of less than −10° C. Also disclosed is a fluoroelastomer that consists essentially of a perfluorovinylether of formula (I) as defined below, a cure site component, perfluoromethylvinylether, and tetrafluoroethylene and/or chlorotrifluoroethylene.
摘要:
Compositions and techniques useful to effectively recycle crosslinked (i.e., vulcanized or cured) fluoroelastomers are disclosed. The invention utilizes an additive system that includes a cure-enhancing additive, a crosslinking agent, and an accelerator.
摘要:
A compound is prepared, suitable for forming fluoroelastomers, having the unique features of a low glass transition temperature and desirable permeation resistance. The compound generally comprises two primary components. The first component is an amorphous copolymer including interpolymerized units derived from one or more perfluorinated ethers. The second component is a curable component including at least one filler having at least 10 parts per 100 parts of the first component. Upon vulcanization the resulting elastomeric compound has desirable physical characteristics as indicated by the durometer, the retraction at lower temperatures (TR-10) and permeation resistance.
摘要:
A composition and method for making a fluoroelastomer is disclosed. The composition comprises a fluoroelastomer containing chlorine and an organic compound containing at least an hydride function. The hydride function has the formula MH where M is Si, Ge, Sn or Pb.
摘要:
The present invention provides a curable composition comprising a fluoropolymer comprising interpolymerized units derived from (i) CF2═CF—Rf, wherein Rf is fluorine or a C1-C8 perfluoroalkyl, (ii) at toast about 10 mole percent of a hydrogen-containing C2-C9 olefin, based on the total moles of said CF2═CFRf and said olefin, (iii) an average of two or more bromine atoms including one or more terminal bromine atom(s) per fluoropolymer chain, (iv) optionally CX2═CX—R, wherein each X is independently H, F, or Cl and R is a halogen or a C1-C8 alkyl or alkenyl group that may include one or more ether linkage(s), (v) optionally a bromine-containing cure site monomer; (b) optionally, a peroxide curing agent; and (c) optionally, a crosslinking co-agent. The invention also provides methods of making and using such fluoropolymer compositions.
摘要:
The present invention provides a curable fluoroelastomer composition comprising: (a) a fluoroelastomer comprising a cure site component having a halogen capable of participation in a peroxide cure reaction; (b) an organic peroxide; and (c) a siloxane or silazane comprising one or more —SiH groups. The curable fluoroelastomer compositions generally show improved processing and the resulting cured fluoroelastomers generally have improved mechanical and physical properties.
摘要:
A component of a fuel management system having a surface that in use will come into contact with fuel. The surface includes a fluoroelastomer layer. The fluoroelastomer layer comprises a hydrotalcite compound dispersed therein.