Artificial corneas suitable for surgical implantation are provided. Embodiments of artificial corneas include an optical an optical element that includes a body having an anterior side and a posterior side, an annular flange extending about the body, the anterior side including an anterior optical surface and the posterior side of the body including a posterior optical surface, and a tissue integration skirt coupled to the optical element, the tissue integration skirt being configured to promote tissue ingrowth, the tissue integration skirt being coupled to the optical element such that at least a portion of a periphery of the annular flange defined between the anterior and posterior sides of the optical element is covered by the tissue integration skirt. Also described are methods for implanting an artificial cornea of the present disclosure, the methods including providing the artificial cornea, removing a section of corneal tissue from the patient's cornea to form a tissue bed of existing tissue to which the artificial cornea can be affixed, implanting the art the artificial cornea such that the posterior side of the artificial cornea is suspended above the interior of the eye, and mechanically affixing the implanted artificial cornea to the existing corneal tissue of the tissue bed.

A cyanoethyl group-containing polymer and a preparation method thereof are provided. The cyanoethyl group-containing polymer is characterized by having very low contents of functional groups other than cyanoethyl groups.

A cyanoethyl group-containing polymer and a preparation method thereof are provided. The cyanoethyl group-containing polymer is characterized by having very low contents of functional groups other than cyanoethyl groups.

A stable aqueous dispersion of multi-stage polymeric particles comprising a polymer and an oligomer, and an aqueous freeze-thaw stable coating composition comprising the aqueous dispersion providing coatings made therefrom with acceptable scrub resistance.

A stable aqueous dispersion of multi-stage polymeric particles comprising a polymer and an oligomer, and an aqueous freeze-thaw stable coating composition comprising the aqueous dispersion providing coatings made therefrom with acceptable scrub resistance.

To provide a perfluoropolymer capable of producing an electrolyte membrane excellent in mechanical strength in high temperature environments; as well as a liquid composition, polymer electrolyte membrane, membrane electrode assembly and polymer electrolyte water electrolyzer, obtainable by using the perfluoropolymer. The perfluoropolymer of the present invention contains perfluoromonomer units, does not substantially contain units having a halogen atom other than a fluorine atom, does not substantially contain units having a ring structure, and has acid-type sulfonic acid groups, wherein the perfluoromonomer units contain at least one type of units A selected from the group consisting of perfluorovinyl ether units and perfluoroallyl ether units; the ion exchange capacity is from 0.9 to 1.4 milliequivalent/gram dry resin; and the storage modulus at 120° C. is at least 100 MPa.

To provide a method for producing a polymer, whereby it is possible to obtain a sulfonic acid group-containing polymer having a high TQ value and a high ion exchange capacity. A method for producing a fluorosulfonyl group-containing fluorinated polymer, which comprises polymerizing a monomer represented by the following formula ml and tetrafluoroethylene, at a temperature of at least 110° C. and at most 250° C.:

##STR00001##

in the above formula, R.sup.F1 and R.sup.F2 are each a C.sub.1-3 perfluoroalkylene group.

Various aspects of the present disclosure are directed toward apparatuses, systems, and methods that include a cord that is flexible and elongated defining a length. The cord may include a core having a porous surface and a porosity-reducing element on at least a portion of the core.

To provide a perfluoropolymer capable of producing an electrolyte membrane excellent in mechanical strength in high temperature environments; as well as a liquid composition, polymer electrolyte membrane, membrane electrode assembly and polymer electrolyte water electrolyzer, obtainable by using the perfluoropolymer.

The perfluoropolymer of the present invention contains perfluoromonomer units, does not substantially contain units having a halogen atom other than a fluorine atom, does not substantially contain units having a ring structure, and has acid-type sulfonic acid groups, wherein the perfluoromonomer units contain at least one type of units A selected from the group consisting of perfluorovinyl ether units and perfluoroallyl ether units; the ion exchange capacity is from 0.9 to 1.4 milliequivalent/gram dry resin; and the storage modulus at 120° C. is at least 100 MPa.

To provide a method for producing pellets from which an ion exchange membrane excellent in stability of the electrolysis voltage can be formed, pellets, and an ion exchange membrane.

The method for producing pellets of the present invention is a method for producing pellets, which comprises extruding a melt containing a fluorinated polymer having groups convertible to ion exchange groups from a die of a melt-extruder to obtain a strand containing the fluorinated polymer, and cutting the strand to obtain pellets containing the fluorinated polymer, wherein the temperature of the die when the melt containing the fluorinated polymer is extruded from the die is less than 200° C., and when the groups convertible to ion exchange groups of the fluorinated polymer are converted to ion exchange groups, the ion exchange capacity of the resulting fluorinated polymer is at least 1.1 milliequivalent/g dry resin.