The present invention provides a tread rubber composition that is excellent in wet grip performance during the initial phase of running and tensile properties, and a pneumatic tire including the tread rubber composition. The present invention relates to a tread rubber composition containing: a diene rubber; silica; and sulfur and/or a sulfur-containing compound, the tread rubber composition satisfying the following relationships (1) to (3):
EB/M300≥50  (1);
M100≥1.7 MPa  (2); and
EB≥500%  (3).

Some variations provide a polysulfide-based copolymer containing first repeat units comprising S.sub.8-derived sulfur atoms bonded via sulfur-sulfur bonds; and second repeat units comprising an organic, non-aromatic thiol molecule. Other variations provide a polysulfide-based copolymer containing first repeat units comprising S.sub.8-derived sulfur atoms bonded via sulfur-sulfur bonds; and second repeat units comprising an organic, non-aromatic unsaturated molecule, wherein the polysulfide-based copolymer has a total sulfur concentration of about 10 wt % or greater. Other variations provide a polysulfide-based copolymer containing first repeat units comprising S.sub.8-derived sulfur atoms bonded via sulfur-sulfur bonds; second repeat units comprising an organic, non-aromatic thiol molecule; and third repeat units comprising an organic, non-aromatic unsaturated molecule. Other variations provide a polysulfide-based copolymer containing first repeat units comprising S.sub.8-derived sulfur atoms bonded via sulfur-sulfur bonds; and second repeat units comprising an organic, non-aromatic thioether molecule. The disclosed polysulfide-based copolymers provide broadband transparency, fracture toughness, fluid resistance, and low cost.

Some variations provide a polysulfide-based copolymer containing first repeat units comprising S.sub.8-derived sulfur atoms bonded via sulfur-sulfur bonds; and second repeat units comprising an organic, non-aromatic thiol molecule. Other variations provide a polysulfide-based copolymer containing first repeat units comprising S.sub.8-derived sulfur atoms bonded via sulfur-sulfur bonds; and second repeat units comprising an organic, non-aromatic unsaturated molecule, wherein the polysulfide-based copolymer has a total sulfur concentration of about 10 wt % or greater. Other variations provide a polysulfide-based copolymer containing first repeat units comprising S.sub.8-derived sulfur atoms bonded via sulfur-sulfur bonds; second repeat units comprising an organic, non-aromatic thiol molecule; and third repeat units comprising an organic, non-aromatic unsaturated molecule. Other variations provide a polysulfide-based copolymer containing first repeat units comprising S.sub.8-derived sulfur atoms bonded via sulfur-sulfur bonds; and second repeat units comprising an organic, non-aromatic thioether molecule. The disclosed polysulfide-based copolymers provide broadband transparency, fracture toughness, fluid resistance, and low cost.

Disclosed are compositions comprising a liquid carrier, a polysulfide rubber curing agent, a metal cation, and an ionic liquid. Also disclosed are methods for curing a surface of an uncured polysulfide rubber. These methods involve applying the disclosed compositions to the surface of the uncured polysulfide rubber.

Disclosed are compositions comprising a liquid carrier, a polysulfide rubber curing agent, a metal cation, and an ionic liquid. Also disclosed are methods for curing a surface of an uncured polysulfide rubber. These methods involve applying the disclosed compositions to the surface of the uncured polysulfide rubber.

The present invention relates to sulfur based polymers and a process of making sulfur based polymers. The invention also relates to sorbents comprising the sulfur-based polymers. The invention also relates to the use of such polymers and sorbents in metal remediation or extraction. The invention also relates to methods of removing heavy metals from fluids.

The present invention relates to sulfur based polymers and a process of making sulfur based polymers. The invention also relates to sorbents comprising the sulfur-based polymers. The invention also relates to the use of such polymers and sorbents in metal remediation or extraction. The invention also relates to methods of removing heavy metals from fluids.

Copolymerization of elemental sulfur with functional comonomers afford sulfur copolymers having a high molecular weight and high sulfur content. Nucleophilic activators initiate sulfur polymerizations at relative lower temperatures and in solutions, which enable the use of a wider range of comonomers, such as vinylics, styrenics, and non-homopolymerizing comonomers. Nucleophilic activators promote ring-opening reactions to generate linear polysulfide intermediates that copolymerize with comonomers. Dynamic sulfur-sulfur bonds enable re-processing or melt processing of the sulfur polymer. Chalcogenide-based copolymers have a refractive index of about 1.7-2.6 at a wavelength in a range of about 5000 nm-8μ.Math.τ.Math.. The sulfur copolymer can be a thermoplastic or a thermoset for use in elastomers, resins, lubricants, coatings, antioxidants, cathode materials for electrochemical cells, dental adhesives/restorations, and polymeric articles such as polymeric films and free-standing substrates. Optical substrates are constructed from the chalcogenide copolymer and are substantially transparent in the visible and infrared spectrum.

Copolymerization of elemental sulfur with functional comonomers afford sulfur copolymers having a high molecular weight and high sulfur content. Nucleophilic activators initiate sulfur polymerizations at relative lower temperatures and in solutions, which enable the use of a wider range of comonomers, such as vinylics, styrenics, and non-homopolymerizing comonomers. Nucleophilic activators promote ring-opening reactions to generate linear polysulfide intermediates that copolymerize with comonomers. Dynamic sulfur-sulfur bonds enable re-processing or melt processing of the sulfur polymer. Chalcogenide-based copolymers have a refractive index of about 1.7-2.6 at a wavelength in a range of about 5000 nm-8μ.Math.τ.Math.. The sulfur copolymer can be a thermoplastic or a thermoset for use in elastomers, resins, lubricants, coatings, antioxidants, cathode materials for electrochemical cells, dental adhesives/restorations, and polymeric articles such as polymeric films and free-standing substrates. Optical substrates are constructed from the chalcogenide copolymer and are substantially transparent in the visible and infrared spectrum.

Compositions of flame retardants and methods of enhancing char formation in a flame retardant-treated substrate. A base material is combined with a flame retardant to form the flame retardant-treated substrate. The flame retardant contains a sulfur copolymer prepared by the polymerization of sulfur monomers with organic monomers. The flame retardant can be deposited on a surface of the base material, coated on the base material, or mixed into the base material. When the flame resistant substrate is on fire, the flame retardant forms a charring layer on the flame retardant-treated substrate. The charring layer can extinguish and prevent the fire from spreading.