Abstract:
An assembly comprises first and second parts which bear against one another, wherein said first part comprises a polyetherketoneketone and said second part comprises a polyetherketoneketone. The parts bear against one another such that one or both of the parts may have a tendency to wear and/or produce wear debris by virtue of contact between the parts. The materials used, however, minimise wear and the production of such wear debris.
Abstract:
There is described a fuel cell or electrolytic cell comprising an ion-conductive polymeric material which includes a first repeat unit of formula (I): - (O-Ph 1 -CO-Ph 1 -O-Ph 1 -CO-Ph 1 ) -, and a second repeat unit of formula (II): - (O-Ph 2 -O-Ph 3 -CO-Ph 4 ) -, or of formula (III): (O-Ph 2 -O-Ph 3 -SO 2 -Ph 4 ) -; wherein Ph 1 , Ph 2 , Ph 3 and Ph 4 independently represent phenyl moieties and wherein said second repeat unit is provided with ion-exchange sites. The polymeric material may include a third repeat unit which is amorphous.
Abstract:
An apparatus for purifying polyketones includes a pressure vessel (2) which communicates with a water supply line (6) for delivering pressurised water into the vessel (2). Downstream of the vessel (2) is a water drain (12) for removing water to waste. In use, a sample of polyketone is placed in the vessel (2) and liquid water at high pressure (e.g. 60 bar) and high temperature (e.g. 260 DEG C) is caused to flow through the vessel whereby relatively pure polyketone for example having relatively low sodium, phosphorus and sulphur impurities may be prepared.
Abstract:
An assembly comprises first and second parts which bear against one another, wherein said first part comprises a polyetherketone and said second part comprises a polyetherketone. The parts bear against one another such that one or both of the parts may have a tendency to wear and/or produce wear debris by virtue of contact between the parts. The materials used, however, minimise wear and the production of such wear debris.
Abstract:
A polymer electrolyte membrane or gas diffusion electrode includes an ion-conducting polymeric material which includes moieties of formula (A) which are substituted on average with more than 1 and 3 or fewer groups (e.g. sulphonate groups) which provide ion-exchange sites and hydrogen atoms of said moieties are optionally substituted, wherein each X in said moieties of formula A independently represent an oxygen or sulphur atom. The ion conducting polymeric material is suitably prepared by controllably sulphonating a polymeric material using about 100% sulphuric acid at 34 C to 36 C.
Abstract:
A polymer electrolyte membrane or gas diffusion electrode includes an ion-conducting polymeric material which includes moieties of formula (A) which are substituted on average with more than 1 and 3 or fewer groups (e.g. sulphonate groups) which provide ion-exchange sites and hydrogen atoms of said moieties are optionally substituted, wherein each X in said moieties of formula A independently represent an oxygen or sulphur atom. The ion conducting polymeric material is suitably prepared by controllably sulphonating a polymeric material using about 100% sulphuric acid at 34 ° C to 36 ° C.
Abstract:
An apparatus for purifying polyketones includes a pressure vessel (2) which communicates with a water supply line (6) for delivering pressurised water into the vessel (2). Downstream of the vessel (2) is a water drain (12) for removing water to waste. In use, a sample of polyketone is placed in the vessel (2) and liquid water at high pressure (e.g. 60 bar) and high temperature (e.g. 260°C) is caused to flow through the vessel whereby relatively pure polyketone for example having relatively low sodium, phosphorus and sulphur impurities may be prepared.
Abstract:
An assembly, for example for a reconstructive joint of the human body, comprises first and second parts which bear against one another. The first and second parts may both comprise a first polymeric material which is preferably polyetheretherketone in combination with carbon fibre.
Abstract:
There is described a fuel cell or electrolytic cell comprising an ion-conductive polymeric material which includes a first repeat unit of formula (I): - (O-Ph 1 -CO-Ph 1 -O-Ph 1 -CO-Ph 1 ) -, and a second repeat unit of formula (II): - (O-Ph 2 -O-Ph 3 -CO-Ph 4 ) -, or of formula (III): (O-Ph 2 -O-Ph 3 -SO 2 -Ph 4 ) -; wherein Ph 1 , Ph 2 , Ph 3 and Ph 4 independently represent phenyl moieties and wherein said second repeat unit is provided with ion-exchange sites. The polymeric material may include a third repeat unit which is amorphous.
Abstract:
A method of preparing an ion-conducting material, for example membrane, having reduced sensitivity to water includes a step of treating an ion-conducting polymeric material (especially a sulphonated polyaryletherketone and/or sulphone) which has at least some crystallinity or which is crystallisable with a means to increase its crystallinity. The ion-conducting material prepared may be used in a Membrane Electrode Assembly of a fuel cell.