A polymer composite of dissimilar polymers covalently bonded at the interface is disclosed. A method for bonding dissimilar polymers includes providing a first precursor to a hydrogel polymer network comprising a first coupling agent; providing a second precursor to a second polymer network comprising a second coupling agent, wherein the hydrogel polymer network and the second polymer network are different; initiating polymerization of the first precursor to form a hydrogel polymer network, wherein the first coupling agent is incorporated into the polymer network with a negligible amount of condensation; initiating polymerization of the second precursor to form a second polymer network, wherein the second coupling agent is incorporated into the second polymer network with a negligible amount of condensation; contacting one of the first hydrogel precursor or the hydrogel polymer network with one of the second polymer precursor or second polymer networks and initiating condensation between the first and second coupling agents to form a covalent bond.

A polymer composite of dissimilar polymers covalently bonded at the interface is disclosed. A method for bonding dissimilar polymers includes providing a first precursor to a hydrogel polymer network comprising a first coupling agent; providing a second precursor to a second polymer network comprising a second coupling agent, wherein the hydrogel polymer network and the second polymer network are different; initiating polymerization of the first precursor to form a hydrogel polymer network, wherein the first coupling agent is incorporated into the polymer network with a negligible amount of condensation; initiating polymerization of the second precursor to form a second polymer network, wherein the second coupling agent is incorporated into the second polymer network with a negligible amount of condensation; contacting one of the first hydrogel precursor or the hydrogel polymer network with one of the second polymer precursor or second polymer networks and initiating condensation between the first and second coupling agents to form a covalent bond.

A defoamer or anti-foam formulation and a process for preparing the same. The process includes in a first step, preparing branched organopolysiloxanes (A) by irradiating organopolysiloxanes (X) of the formula (1)

R.sup.1.sub.3-a(R.sup.2O).sub.aSi—[OSiR.sup.3.sub.2].sub.n—OSi(OR.sup.2).sub.aR.sup.1.sub.3-a   (1).

Where with high-energy radiation, the viscosity of the organopolysiloxanes (A) is at least 40% higher than the viscosity of the organopolysiloxanes (X). In a second step, the branched organopolysiloxanes (A) are treated with a filler (B) which is selected from precipitated and/or fumed silicas, and organopolysiloxane resins (C).

A defoamer or anti-foam formulation and a process for preparing the same. The process includes in a first step, preparing branched organopolysiloxanes (A) by irradiating organopolysiloxanes (X) of the formula (1)

R.sup.1.sub.3-a(R.sup.2O).sub.aSi—[OSiR.sup.3.sub.2].sub.n—OSi(OR.sup.2).sub.aR.sup.1.sub.3-a   (1).

Where with high-energy radiation, the viscosity of the organopolysiloxanes (A) is at least 40% higher than the viscosity of the organopolysiloxanes (X). In a second step, the branched organopolysiloxanes (A) are treated with a filler (B) which is selected from precipitated and/or fumed silicas, and organopolysiloxane resins (C).

A process for end capping and chain extending silanol terminated polydiorganosiloxanes with a mixture of one or more alkylacetoxydialkoxysilanes and one or more alkyldiacetoxyalkoxysilanes. The resulting capped polymeric material may be utilised as a polymer in e.g. a one-part alkoxy sealant composition such as, for example, an alkoxy low modulus clean (non-staining) or clear sealant composition.

An oil repellent agent including a modified natural product having at least one hydroxyl group, wherein a hydrogen atom of the hydroxyl group is replaced with an R group represented by —Y—Z, wherein Y represents a direct bond, —C(═O)—, —C(═O)—NR′— or —C(═S)—NR′—, where R′ represents a hydrogen atom or a C.sub.1 to C.sub.4 alkyl group); and Z represents a hydrocarbon group having 1 to 40 carbon atoms and optionally having a substituent or a polysiloxane. The natural material is a natural product other than starch and preferably is a monosaccharide, a polysaccharide, glycerin or polyglycerin. Also disclosed is a textile product to which the oil-resistant agent is attached, an oil-resistant paper and a method of treating paper with the oil-resistant agent.

An oil repellent agent including a modified natural product having at least one hydroxyl group, wherein a hydrogen atom of the hydroxyl group is replaced with an R group represented by —Y—Z, wherein Y represents a direct bond, —C(═O)—, —C(═O)—NR′— or —C(═S)—NR′—, where R′ represents a hydrogen atom or a C.sub.1 to C.sub.4 alkyl group); and Z represents a hydrocarbon group having 1 to 40 carbon atoms and optionally having a substituent or a polysiloxane. The natural material is a natural product other than starch and preferably is a monosaccharide, a polysaccharide, glycerin or polyglycerin. Also disclosed is a textile product to which the oil-resistant agent is attached, an oil-resistant paper and a method of treating paper with the oil-resistant agent.

Film-forming polymers that contain covalently-attached or non-covalently bound light-filtering, e.g., UV-absorbing, compounds and their use as a skin-protectant coating, such as a sunscreen, are disclosed.

Film-forming polymers that contain covalently-attached or non-covalently bound light-filtering, e.g., UV-absorbing, compounds and their use as a skin-protectant coating, such as a sunscreen, are disclosed.

An object of the present invention is to provide a polyorganosiloxane-containing graft copolymer powder capable of providing a resin composition and a molded article which are excellent in balance between colorability and mechanical properties such as impact resistance. The polyorganosiloxane-containing graft copolymer powder according to the present invention is a graft copolymer powder obtained by graft-polymerizing a mixture (B) of a vinyl monomer (b1) having an epoxy group and another vinyl monomer (b2) to a rubber (A) containing a polyorganosiloxane, wherein the content of the polyorganosiloxane (A1) contained in the rubber (A) is 12 to 50% by mass, the mass average particle diameter of the polyorganosiloxane-containing graft copolymer powder is 300 to 2000 nm, and the epoxy equivalent of the polyorganosiloxane-containing graft copolymer powder is 2500 to 7800 g/eq.