The invention relates to methods of lubricating biological tissue, such as joints, bone, ocular tissue, nasal tissue, tendons, tendon capsule, and vaginal tissue, by contacting the biological tissue with an effective amount of a block copolymer lubricating composition which functions at least or better than lubricin. In particular embodiments, the method is used to treat osteoarthritis. In specific embodiments, the block copolymer has an ammonium-containing polymer block and a non-ionic hydrophilic polymer block, or the copolymer has a carboxylic acid-containing polymer block and a non-acid non-ionic hydrophilic polymer block.

The copolymer includes divalent units represented by formula —[CF.sup.2—CF.sup.2]—, divalent units represented by formula: (I), and one or more divalent units independently represented by formula: (II) When Z is hydrogen, the copolymer has an alpha transition temperature of up to 100 ?C. The copolymer has an —SO.sub.3Z equivalent weight in a range from 300 to 1400, and a variation of the copolymer in which —SO.sub.3Z is replaced with —SO.sub.2F has a melt flow index of up to 80 grams per ten minutes measured at a temperature of 265° C. and at a support weight of 5 kg. A catalyst ink or polymer electrolyte membrane including the copolymer are also provided. ##STR00001##

A process prepares a cross-linked polymer containing urethane groups and silicon atoms. Starting materials of the process include a compound A) with a five-membered cyclic monothiocarbonate group, a compound B) with an amino group, selected from primary or secondary amino groups or blocked amino groups, and optionally, a compound C) with at least one functional group that reacts with a group —SH. One of the compounds contains a silicon-functional group. In one example of the process, compounds A) and B), and optionally C), are then reacted under exclusion of water to obtain a polymer with curable silicon-functional groups. The polymer is applied to a surface, gap, or a three-dimensional template. The silicon-functional groups are cured with ambient water. The polymer contains 0.001 to 0.3 mol of silicon per 100 g of the polymer.

An adhesive hydrogel has low contact resistance against the body surface and excellent conformability and adhesiveness to the body surface, so that noise generation can be reduced. Such adhesive hydrogel enables measurements of weak fetal heart rate signals. The adhesive hydrogel includes a polymer matrix prepared by crosslinking-copolymerization of an acrylamide derivative, which is a nonionic polymerizable monomer including a polymerizable carbon-carbon double bond in a molecule, and polyfunctional (meth)acrylamide, which is a crosslinkable monomer comprising 2 or more polymerizable carbon-carbon double bonds in a molecule, water, a polyvalent alcohol, and an electrolyte salt, wherein a laminate of the adhesive hydrogel with an Ag/AgCl sheet exhibits the impedance of 1Ω to 100Ω at the frequency of 0.1 Hz measured in accordance with the method of ANSI/AAMI EC12:2000, and the dynamic elastic modulus G′ at the frequency of 1 Hz measured at 25° C. and dispersed frequencies is 1.0×10.sup.3 Pa to 1.0×10.sup.4 Pa.

The present invention relates to an amorphous polyolefinic ionomer and a process for the preparation of an amorphous polyolefinic ionomer.

Provided is a polymer composition having sufficient heat resistance and optical characteristics. Disclosed is a polymer composition comprising a polymer containing a monomer unit having a ring structure, wherein the polymer composition is, for instance, polymer composition A containing a polymer of a monomer having a ring structure, and when a flat plate of 120 mm×100 mm×3.0 mm in thickness is molded from the polymer composition under the following injection molding conditions of: (1) using a non-vent-type injection molding machine; (2) using a cold runner mold; (3) having a cylinder temperature of 260° C.; and (4) having a ratio of an injection volume of the injection molding machine to a molded product volume of 4.5, a difference between a monomer content in the flat plate obtained at a cooling time of 5 min and a monomer content in the flat plate obtained at a cooling time of 1 min is 1000 ppm by mass or more and 12000 ppm by mass or less.

A particulate compacted copolymer polyvinyl alcohol-based composition that can be used as a plugging agent for minimizing or eliminating loss of circulation of fluids during the process of well drilling, workover, completion and cementing in the production of oil and gas.

A method of preparing a modified polyvinyl acetate includes subjecting a mixed liquor L1 containing a functional monomer to a first reaction with a first vinyl acetate monomer, followed by adding a first initiator to carry out a second reaction to obtain a mixed liquor L2; subjecting an acrylate monomer, a second vinyl acetate monomer, a second initiator and the mixed liquor L2 to carry out a third reaction to obtain a mixed liquor L3; and subjecting a third initiator and the mixed liquor L3 to carry out a fourth reaction under the air-tight and ultrasonic conditions. The functional monomer is selected from acrylic acid, oleic acid or butenedioic acid. Uses of modified polyvinyl acetate obtained by the method and oil-based drilling fluid containing the modified polyvinyl acetate are also disclosed.

Provided herein are sulfonate-based water-soluble photoswitches that, in contrast to existing systems, trigger a volumetric expansion in hydrogels upon exposure to photons; contraction is in turn observed under dark conditions in a highly reversible manner.

A copolymer including units derived from fluoro monomers of formula (I):

CX.sub.1X.sub.2═CX.sub.3X.sub.4  (I) in which each of the X.sub.1, X.sub.2, X.sub.3 and X.sub.4 is independently chosen from H, F and alkyl groups including from 1 to 3 carbon atoms which are optionally partially or totally fluorinated, the H and/or F atoms of the fluoro monomers being partially replaced with photoactive groups of formula —Y—Ar—R in the copolymer; Y representing an oxygen atom or an NH group or a sulfur atom, Ar representing an aryl group, preferably a phenyl group, and R being a monodentate or bidentate group including from 1 to 30 carbon atoms. The fluoro monomers of formula (I) of the copolymer include vinylidene fluoride and trifluoroethylene. Also, a process for preparing this copolymer, a composition including this copolymer, and a film obtained from the copolymer.