The present disclosure relates to a single-use filter component for removing NO.sub.2 in an air-treatment system, the component comprising a polymeric composition as an air-filtration medium, the polymeric composition comprising a plurality of free vinyl groups, wherein the component permits inspection of the air-filtration medium by an end-user to determine when the filter is spent, based on a white to yellow colour change, or comprises an optical sensor configured to notify the end-user of the colour change. The present disclosure further relates to a single-use filter component for simultaneously removing NO.sub.2 in an air-treatment system, wherein the component comprises a HEPA filter formed from a polymeric composition comprising a plurality of free vinyl groups. The present disclosure further relates to an air treatment system, to a method of treating air and to the use of a polymer or copolymer of divinylbenzene for forming an air-filtration medium.

A nanoparticle includes a copolymer comprising a vinyl-aromatic monomer and a heterocyclic monomer. The copolymer is crosslinked with a multifunctional crosslinking agent polymerizable through an addition reaction. A nanoparticle and elastomer composition is disclosed. Several methods of mixing heterocyclic and non-heterocyclic monomer nanoparticles into an elastomer are also disclosed. These methods include mixing in a multi-elements static mixer and an intermeshing mixer with venting, among others.

A nanoparticle includes a copolymer comprising a vinyl-aromatic monomer and a heterocyclic monomer. The copolymer is crosslinked with a multifunctional crosslinking agent polymerizable through an addition reaction. A nanoparticle and elastomer composition is disclosed. Several methods of mixing heterocyclic and non-heterocyclic monomer nanoparticles into an elastomer are also disclosed. These methods include mixing in a multi-elements static mixer and an intermeshing mixer with venting, among others.

A method can be used for manufacturing an ethylene-propylene-diene terpolymer for a fuel cell. A polymerization step includes subjecting an organic chelate compound forming a coordinate bond, a vanadium-based Ziegler-Natta catalyst, an organoaluminum compound, and ethylene, propylene, and diene monomers, together with a solvent, to polymerization in a reactor. A separation step includes recovering residual catalysts and unreacted monomers from the stream discharged from the reactor. An acquisition step includes recovering the solvent from the stream deprived of the residual catalysts and unreacted monomers to acquire the ethylene-propylene-diene terpolymer.

A method can be used for manufacturing an ethylene-propylene-diene terpolymer for a fuel cell. A polymerization step includes subjecting an organic chelate compound forming a coordinate bond, a vanadium-based Ziegler-Natta catalyst, an organoaluminum compound, and ethylene, propylene, and diene monomers, together with a solvent, to polymerization in a reactor. A separation step includes recovering residual catalysts and unreacted monomers from the stream discharged from the reactor. An acquisition step includes recovering the solvent from the stream deprived of the residual catalysts and unreacted monomers to acquire the ethylene-propylene-diene terpolymer.

A cyclic olefin copolymer includes one or more olefin-derived constituent units (A) represented by General Formula (I), one or more cyclic olefin-derived constituent units (C) represented by General

Formula (II), one or more cyclic non-conjugated diene-derived constituent units (B) represented by General Formula (III), and one or more cyclic olefin-derived constituent units (D) represented by General Formula (V), in which, when a total number of moles of the constituent units in the cyclic olefin copolymer is 100 mol %, a content of the constituent unit (C) is 5 mol % or more and 40 mol % or less.

A cyclic olefin copolymer includes one or more olefin-derived constituent units (A) represented by General Formula (I), one or more cyclic olefin-derived constituent units (C) represented by General

Formula (II), one or more cyclic non-conjugated diene-derived constituent units (B) represented by General Formula (III), and one or more cyclic olefin-derived constituent units (D) represented by General Formula (V), in which, when a total number of moles of the constituent units in the cyclic olefin copolymer is 100 mol %, a content of the constituent unit (C) is 5 mol % or more and 40 mol % or less.

A cyclic olefin copolymer includes one or more olefin-derived constituent units (A) represented by General Formula (I), one or more cyclic olefin-derived constituent units (C) represented by General

Formula (II), one or more cyclic non-conjugated diene-derived constituent units (B) represented by General Formula (III), and one or more cyclic olefin-derived constituent units (D) represented by General Formula (V), in which, when a total number of moles of the constituent units in the cyclic olefin copolymer is 100 mol %, a content of the constituent unit (C) is 5 mol % or more and 40 mol % or less.

An aqueous dispersion of a hydrophobically-modified alkali-soluble multistage polymer useful as a thickener affording high thickening efficiency and an aqueous coating composition comprising such aqueous dispersion showing good stability after heat aging without compromising stability upon addition of colorants.

An aqueous dispersion of a hydrophobically-modified alkali-soluble multistage polymer useful as a thickener affording high thickening efficiency and an aqueous coating composition comprising such aqueous dispersion showing good stability after heat aging without compromising stability upon addition of colorants.