Polyurethane foams are made by curing a reaction mixture that contains an aromatic polyisocyanate, at least one isocyanate-reactive material having an average functionality of at least 2 and an equivalent weight of at least 200 per isocyanate-reactive group, at least one blowing agent, at least one surfactant and at least one catalyst, and a certain 3-oxopropanamide compound. Foams so produced emit low levels of aldehydes.

Aerogels comprising a hydrophobic polyimide moiety, including hydrophobic polyimide aerogels, as well as methods of manufacture and applications thereof, are generally described.

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Polyurethane-polyisocyanurate foams are prepared using a polyether polyol made from an alkylene oxide mixture that contains a specified proportion of ethylene oxide. The selection of proper polyol equivalent weight and ethylene oxide content leads to the production of foams having a useful combination of properties.

The present disclosure relates to acid-blocked pyrrolidine catalysts for use in a polyurethane formulation. The polyurethane formulation includes the acid-blocked pyrrolidine catalyst, a compound containing an isocyanate functional group, an active hydrogen-containing compound and a halogenated olefin compound. The use of such acid-blocked pyrrolidine catalysts show surprisingly low reactivity with halogenated olefin compounds yet sufficient reactivity to catalyze polyurethane formation.

A process is described for producing PU foams, especially rigid PU foams, based on foamable reaction mixtures containing polyisocyanates, compounds having reactive hydrogen atoms, blowing agents, foam stabilizers, and possibly further additives, wherein polymer particles are additionally used, the average particle size of the polymer particles being <100 μm, preferably <70 μm, especially 5 to 50 μm.

Polyether polyols are prepared by polymerizing unsaturated monomers in a continuous phase of a base polyol. A macromer or polymerization produce of such a macromer is present during the polymerization to stabilize the polymer particles as they form. The macromer is a polyether capped with certain unsaturated epoxide compounds.

A reaction system for forming a viscoelastic polyurethane foam includes an isocyanate component and an isocyanate-reactive component that includes at least a polyol component, an additive component, and a preformed aqueous polymer dispersant. The mixture includes 50.0 wt % to 99.8 wt % of the polyol component, 0.1 wt % to 49.9 wt % of the additive component, and 0.1 wt % to 6.0 wt % of the preformed aqueous polymer dispersant. The aqueous polymer dispersant has a pH from 6.0 to 12.0 and includes from 5 wt % to 60 wt % of a polymeric component and from 40 wt % to 95 wt % of a fluid medium. The polymeric component includes at least one base polymer derived from 20 wt % to 100 wt % of at least one hydrophilic acid monomer having at least one carbonyl group, phosphate group, phosphonate group, or sulfonyl group, and optionally derived from at least one hydrophobic terminally unsaturated hydrocarbon monomer.

New shape memory polymer compositions, methods for synthesizing new shape memory polymers, and apparatus comprising an actuator and a shape memory polymer wherein the shape memory polymer comprises at least a portion of the actuator. A shape memory polymer comprising a polymer composition which physically forms a network structure wherein the polymer composition has shape-memory behavior and can be formed into a permanent primary shape, re-formed into a stable secondary shape, and controllably actuated to recover the permanent primary shape. Polymers have optimal aliphatic network structures due to minimization of dangling chains by using monomers that are symmetrical and that have matching amine and hydroxl groups providing polymers and polymer foams with clarity, tight (narrow temperature range) single transitions, and high shape recovery and recovery force that are especially useful for implanting in the human body.

Isocyanate-reactive composition that include a polyol blend, a blowing agent composition, and a catalyst. The polyol blend includes a polyether polyol having a functionality of 2 to 6 and an OH number of 20 to 50 mg KOH/g, which is present in an amount of at least 30% by weight, based on total weight of the isocyanate-reactive composition, and an aromatic polyester polyol having a functionality of 1.5 to 3 and an OH number of 150 to 450 mg KOH/g, which is present in an amount of at least 40% by weight, based on total weight of the isocyanate-reactive composition. The blowing agent composition includes water, the water being present in an amount of 1 to 20% by weight, based on total weight of the isocyanate-reactive composition and in an amount of at least 90% by weight, based on total weight of the blowing agent composition. The isocyanate-reaction composition has a green content of at least 30% by weight, based on total weight of the isocyanate-reactive composition. Polyurethane foam-forming reaction mixtures, polyurethane foams, multi-layer composite articles and methods for their production are also described.

A method for preparing a semi-rigid melamine foam plastic, comprising Step (1): adding a formaldehyde solution and polyvinyl alcohol (PVA) to a reactor, heating the reactor, and adding alkali; Step (2): feeding solid melamine powder and a modifier 3-aminopropyltriethoxysilane (APTES) into the reactor, raising the temperature in the reactor to 75-85° C., adjusting the pH value of the solution of material by adding acid; heating the solution of material, performing a heat preservation reaction, and then adding alkali, Step (3): feeding a predetermined amount of foaming agent, emulsifier, auxiliary agent and curing agent into a stirring reactor to obtain a mixed auxiliary agent; pumping the mixed auxiliary agent and the semi-rigid modified melamine resin into an emulsifier; placing the emulsified resin into a microwave heating chamber for microwave foaming; Step (4): cutting the semi-rigid melamine foam plastic obtained in step (3) and then drying.