The present disclosure relates to thermally expandable microspheres comprising a polymeric shell surrounding a hollow core, wherein the hollow core comprises a blowing agent, and the polymeric shell comprises a carboxylate-functionalised cellulose, wherein the thermally expandable microspheres have a temperature at which expansion starts, T.sub.Start, of from 80° C. to less than 135° C. The present disclosure further relates to a process for preparing expandable microspheres as well as to thermally expandable microspheres obtained by such process, the process comprising mixing a carboxylate-functionalised cellulose, an organic solvent, a blowing agent and, optionally, a polymer shell enhancer and then spraying the thus obtained mixture into a drying equipment to produce the thermally expandable microspheres having a polymeric shell surrounding a hollow core, in which the polymeric shell comprises the carboxylate-functionalised cellulose, and the hollow core comprises the blowing agent.

Provided is a porous polytetrafluoroethylene membrane in which an absolute value of a difference in lightness between one principal surface and the other principal surface is 1.0 or more, where the lightness is lightness L* of CIE 1976 (L*, a*, b*) color space specified in JIS Z8781-4: 2013. The porous polytetrafluoroethylene membrane may be colored black or gray. The porous polytetrafluoroethylene membrane provided can have properties with a reduced coloring-induced deterioration.

Disclosed is a polyolefin thermal insulation foam and use thereof, and to a method for preparing a physically foamed polyolefin thermal insulation foam, which can be recycled well and which has excellent flexibility characteristics.

The application discloses cellulose ester compositions comprising two or more miscible blends of cellulose ester each comprising a plurality of propionyl substituents having tunable rheology and physical properties not achievable by any one of the cellulose esters alone. These cellulose ester compositions can be further processed, with or without other materials such as plasticizers, flame retardants, and blowing agents, and converted into articles. These cellulose ester compositions have higher modulus and have low to no butyryl/butyric acid content relative to cellulose acetate butyrate (“CAB”) cellulose ester compositions made from CABs having a butyryl content of greater than 30 wt %.

Embodiments may include an insulated structure. The insulated structure may include a plurality of structural support members coupled together to form a frame. The insulated structure may also include a plurality of first wall boards attached to an exterior side of the frame to form an exterior wall or surface of the structure. The insulated structure may further include a spray foam insulation positioned within at least one of the wall cavities of the structure. The spray foam insulation may have an insulative R-value greater than or equal to 6.0 per inch at 40° F. The spray foam formulation may be made from a formulation that includes a reaction product of a polyisocyanate compound and a polyol compound and a blowing agent. The blowing agent may include a mixture of n-pentane and isopentane, where the mixture is at least 75% isopentane.

Rigid polyurethane or polyisocyanurate foams, polyester polyols used to produce them, and methods for formulating the foams are disclosed. The foams comprise a reaction product of a polyisocyanate, a polyester polyol, water, a surfactant, a catalyst and optional ingredients. The polyester polyols comprise a phthalimide-containing polyacid, a phthalimide-containing polyol, or a combination thereof. Rigid foams produced from the polyester polyols exhibit higher thermal stability and/or greater intumescence when compared with foams made from other polyester polyols. The phthalimide-containing polyester polyols should allow formulators to improve the flammability performance of rigid foams with reduced levels of flame retardants and/or lower index and should facilitate the production of thinner insulation panels.

What is described is a composition for production of rigid polyurethane foam, comprising at least one isocyanate component, a polyol component, optionally a foam stabilizer, optionally blowing agent, wherein the composition contains at least one catalyst that catalyses the formation of a urethane or isocyanurate bond, wherein the catalyst comprises salts of amino acid derivatives.

The present invention relates to compositions for use in refrigeration, air-conditioning, and heat pump systems wherein the composition comprises a fluoroolefin and at least one other component. The compositions of the present invention are useful in processes for producing cooling or heat, as heat transfer fluids, foam blowing agents, aerosol propellants, and fire suppression and fire extinguishing agents.

An isocyanate-reactive composition including: (i) at least one isocyanate-reactive compound; and (ii) a predetermined amount of at least one thixotropic modifier; and a foam-forming composition for producing a polyurethane or polyisocyanurate foam including: (A) at least one isocyanate component; and (B) at least one isocyanate-reactive component; wherein the at least one iso-cyanate-reactive component is the above isocyanate-reactive composition.

Disclosed are a heat-expandable polyvinylidene chloride microsphere and its preparation method. The preparation method comprises: by weight, dissolving 250 to 550 parts of an aqueous-phase polymerization inhibitor, 20 to 100 parts of a dispersant, and 3 to 15 parts of a co-dispersing monomer in deionized water, adjusting a pH value of the solution and cooling the solution to obtain an aqueous phase for later use; dissolving 5 to 15 parts of a cross-linking agent and 20 to 45 parts of an initiator in 1000 to 2000 parts of a mixed monomer, and cooling the solution to obtain an oil phase for later use; mixing and homogenizing the aqueous phase and the oil phase with stirring to obtain a homogenized mixed solution; adding 300 to 550 parts of a foaming agent to the homogenized mixed solution and homogenizing the resulting solution with stirring to obtain a homogenized mixed solution containing the foaming agent; reacting the homogenized mixed solution containing the foaming agent with stirring; at the end of the reaction, cooling to room temperature, filtering the resulting suspension to obtain filtrate, centrifuging and dehydrating the filtrate, and drying to obtain the heat-expandable polyvinylidene chloride microsphere product. This disclosure has the advantages of simple process and environmental friendliness, and the obtained product has good performance.