The invention pertains generally to a process and a composition-of-matter for a shelf-stable open cell polyurethane HFO-blown two-component polyurethane foam composition having improved flame-retardant properties through the use of at least one organo-tin containing catalyst and at least one potassium containing catalyst; and at least one dimorpholino-based ether catalyst, a ratio of the at least one potassium-containing catalyst to the tin-containing catalyst being at least approximately 1.5:1.0, the at least one surfactant comprising a polydimethylsiloxane (PDMS) backbone and polyethylene oxide-co-propylene oxide (PEO-PPO) random copolymer grafts; and the added water comprises at least 8 weight percent of said B-side reactants, the polyurethane foam having a Class B rating with a flame spread between 25 and 75 inclusive and a smoke developed of under 450 using ASTM E 84 testing protocol.

A reaction system for forming a viscoelastic polyurethane foam includes an isocyanate component that has at least one isocyanate and an isocyanate-reactive component that is a mixture formed by adding at least a polyol component, an additive component, and a preformed aqueous polymer dispersion. The mixture includes, based on the total weight of the mixture, from 50.0 wt % to 99.8 wt % of a polyol component including at least one polyether polyol, from 0.1 wt % to 50.0 wt % of an additive component including at least one catalyst, and from 0.1 wt % to 6.0 wt % of a preformed aqueous polymer dispersion. The preformed aqueous polymer dispersion has a solids content from 10 wt % to 80 wt %, based on the total weight of the preformed aqueous polymer dispersion, and is one of an aqueous acid polymer dispersion or an aqueous acid modified polyolefin polymer dispersion in which the polyolefin is derived from at least one C.sub.2 to C.sub.20 alpha-olefin.

A method for the synthesis of an auxetic polyurethane foam with a defined cell structure and an auxetic polyurethane foam substrate obtainable by a method according to the invention. The method includes mixing a polyol reagent and a foaming reagent, forming a reaction mixture, mixing an isocyanate with the reaction mixture, compressing and/or contracting the isocyanate/reaction mixture, and allowing the compressed and/or contracted isocyanate/reaction mixture to cure.

The present disclosure relates to polyurethane based switchable adhesives. In at least one embodiment, a switchable adhesive composition comprises an adhesive component, which is formed from at least one isocyanate and a material or materials capable of undergoing cross-linking with isocyanate other than by free radical polymerization.

PIPA polyols are made in a two-step process. In the first step, a base polyether polyol and a polyisocyanate are reacted to form a mixture that contains unreacted base polyol, unreacted polyisocyanate and adducts of the base polyol and polyisocyanate. A low equivalent weight polyol is then added and reacted in a second step to form the dispersion. The process unexpectedly produces a stable dispersion of the fine PIPA particles in the base polyol, even when the base polyol contains mostly secondary hydroxyl groups. The process also permits the tuning of product viscosity by increasing or decreasing the extent of reaction in the first step.

A process for forming a combustion-modified ether (CME) polyurethane foam includes providing a polyol component including a PIPA polyol that is a dispersion having a solids content from 10 wt % to 75 wt %, based on a total weight of the PIPA polyol, providing an isocyanate component that includes at least one polyisocyanate, providing an additive component that includes at least one flame retardant, and forming a reaction mixture including the polyol component, the isocyanate component, and the additive component to form a CME polyurethane foam. The reaction mixture has an isocyanate index from 90 to 150. The PIPA polyol is a reaction product of a mixture including at least a low equivalent weight polyol having a number average hydroxyl equivalent weight of less than 80, a polyisocyanate compound having a number average isocyanate equivalent weight that is less than 225, and a liquid base poly ether polyol having a number average hydroxyl equivalent weight of at least 200 and at least 80% of secondary hydroxyl groups based on a total amount of hydroxyl groups in the liquid base polyether polyol.

A method of making a hydroxyl-terminated thioketal diol is provided, the method comprising reacting a thioketal ester with a non-pyrophoric reducing agent to form a hydroxyl-terminated thioketal diol. The hydroxyl-terminated thioketal diol can be 2,2-(propane-2,2-diylbis(sulfanediyl)) diethanol. The non-pyrophoric reducing agent can be a sodium aluminum hydride, for example, sodium bis (2-methoxyethoxy)aluminum hydride. The thioketal ester can be dimethyl 2,2-(propane-2,2-diylbis(sulfanediyl)) diacetate. A biodegradable matrix prepared by reacting a hydroxyl-terminated thioketal diol with an isocyanate is provided. A method of making a biodegradable polyurethane composite is also provided.

Polyurethane material for indicating pH at a locus, preferably as indication of presence of microbes, comprising a polyurethane network having immobilised therein one or more hydrophilic copolymers, the or each said copolymer comprising:

hydrophilic monomer; and
indicating monomer, which provides an indication in response to a change in hydrophilic state of said hydrophilic monomer and/or copolymer;
characterised in that the or each copolymer further comprises one or a plurality of ionisable groups or moieties or polymerisable monomers having one or more characteristic pKa values in the range 5 to 10 and which are responsive to pH at the locus in the range pH 5 to pH 10
and in that hydrophilic state of hydrophilic copolymer is dependent on ionisation of said ionisable groups, moieties or monomers; kit and device comprising the material and process for preparation thereof; and use in detecting or sensing microbes or pH.

The present invention provides a curable composition comprising a urethane-modified epoxy resin (A) as an essential component of a main material, and an acid anhydride (B) as an essential component of a curing agent, wherein the urethane-modified epoxy resin (A) is a reaction product of a polyisocyanate compound (a1), a polyester polyol (a2), and a hydroxyl group-containing epoxy resin (a3) as essential reaction raw materials. The curable composition of the invention is advantageous in that a cured product having excellent fracture toughness and excellent tensile strength can be formed from the composition.

A thermoset polyisobutylene network polymer includes a polyisobutylene diol residue, a diisocyanate residue, and at least one crosslinking compound residue selected from the group consisting of a residue of a sorbitan ester and a residue of a branched polypropylene oxide polyol.