The present disclosure discloses a preparation method of an ultraviolet (UV)-resistant and transparent lignin-based polyurethane (PU) elastomer. During the synthesis process, natural lignin-based polyols are directly used as an end-capping agent, isophorone diisocyanate and 2,2-dimethylolbutyric acid are used as a hard segment and polyether chain polyols are used as a soft segment, to synthesize a PU elastomer with a transparent brown appearance, excellent high elasticity and elastic recovery performance, as well as excellent mechanical properties, excellent UV resistance and repeatable processability. The lignin-based PU elastomer has a simple preparation process, and has great potential values for use in the fields such as PU elastomer film, fabric coating, and elastic fiber and biomass polymer materials.

A method of producing a polyurethane or polyisocyanurate foam is provided which involves the use of a specific combination of hydrofluoroolefin blowing agents and cell nucleators. The resulting foams have excellent long term thermal insulating performance and have reduced thickness in comparison to conventional thermal insulating boards. The rigid polyurethane and polyisocyanurate boards may be used to insulate refrigeration bodies, such as those employed in vehicles comprising refrigeration units, and cold storage containers.

A trimerization catalyst composition suitable for making a polyisocyanurate comprising (insulation) foam, said composition comprising at least a trimerization catalyst compound selected from one or more organic salts from alkoxides wherein said organic salt is selected from alkali metal, earth alkali metal, a transition metal such as Ti and/or quaternary ammonium organic salts.

A catalyst composition for making polyurethane foam, the catalyst composition including a compound having a general formula R.sup.1R.sup.2R.sup.3N, wherein each of R.sup.1, R.sup.2 and R.sup.3 are independently selected from the group consisting of: a compound according to formula (I):

##STR00001##

wherein n=1 to 5; and R4, R5 and R6 are each independently hydrogen, methyl, ethyl and propyl groups; hydrogen, a C1-C6 alkyl group compound, a C1-C6 cycloalkyl group compound, a C1-C6 alkenyl group compound, a C1-C6 alkynyl group compound, a C1-C6 aryl group compound, and a C1-C6 aralkyl group compound, each group being substituted or unsubstituted; wherein at least one of R.sup.1, R.sup.2 and R.sup.3 is a compound according to formula (I). A polyurethane composition and method for forming a polyurethane foam are also disclosed.

A method for preparing rigid polyurethane (PUR) foams or rigid polyisocyanurate (PIR) foams in which method the rigid PUR or PIR foam is prepared by reacting a composition (C) comprising: at least one isocyanate-reactive component (B1) having functional groups selected from hydroxyl, amine and thiol groups; at least one isocyanate component (A1) having an average functionality of less than 2.70; and at least one blowing agent [blowing agent (BA), herein after]; with the proviso that the overall average functionality [F.sub.n,avg(A), herein after] of all isocyanate components present in the composition (C) is less than 2.70; wherein the composition (C) is characterized by an isocyanate index X, wherein the rigid PUR or PIR foams are produced by depositing the composition (C) between two gas-tight facing sheets and wherein the rigid PUR or PIR foam is characterized by a difference Δλ between the initial thermal conductivity value λ.sub.ini and the aged thermal conductivity value λ.sub.aged of said rigid PUR or PIR foam wherein: when X≤200 then Δλ<1.35; and when X>200 then Δλ<[6.49−(4.46*F.sub.n,avg(A))−(0.02348*X)+(0.492*F.sub.n,avg(A)*F.sub.n,avg(A))+(0.01343*F.sub.n,avg(A)*X)+0.3].

Foam wall structures and methods for making them are described. The wall structures include a frame, a foam panel overlying a front surface of the frame, and a polyurethane foam layer disposed in a cavity of the wall structure. The polyurethane foam layer has a density, as determined by ASTM D1622-14, of at least 44 kg/m.sup.3 and exhibits ASTM E84-16 Class A flame spread and smoke development characteristics. The polyurethane foam layer is the cured reaction product of a polyurethane foam-forming composition that includes a polyisocyanate, an aromatic polyester polyol having a functionality of greater than 2.5 and an OH number of at least 300 mg KOH/g, which is present in an amount of at least 50% by weight, based on the total weight of the polyurethane foam-forming composition less the weight of the polyisocyanate, a catalyst, and a blowing agent composition. The blowing agent composition includes water and a hydrofluoroolefin.

Isocyanate-reactive compositions that include a hydrofluoroolefin blowing agent, polyurethane foam-forming compositions, as well as spray-applied polyurethane foams formed therefrom that can provide structural support to wall structures and can also exhibit ASTM E84-16 Class A flame spread and smoke development characteristics at a foam thickness of 4 inches.

The invention provides polyurethane and polyisocyanurate foams and methods for the preparation thereof. More particularly, the invention relates to closed-celled, polyurethane and polyisocyanurate foams and methods for their preparation. The foams are characterized by a fine uniform cell structure and little or no foam collapse. The foams are produced with a polyol premix composition which comprises a combination of a hydrohaloolefin blowing agent, a polyol, a silicone surfactant, and a precipitation-resistant metal-based catalyst used alone or in combination with an amine catalyst.

Described herein is a cast elastomer including graphene nano platelets and a process for preparing the same.

Described herein is a method for the preparation of a rigid polyisocyanate based foam, including mixing (a) polyisocyanate, (b) at least one compound having at least two hydrogen atoms reactive towards isocyanates, (c) optionally flame retardant, (d) blowing agent, (e) catalyst and (f) optionally further additives, to form a reaction mixture and reacting the reaction mixture to obtain the polyurethane based rigid foam where the compound reactive towards isocyanates (b) includes an aromatic polyetherpolyol (b2) and at least one compound selected from the group consisting of an aromatic polyesterpolyol (b1) and a polyetherpolyol (b3) different from polyether (b2). Also described herein is a rigid polyisocyanate based foam obtained from such a method and a polyol component for the production of a polyisocyanate based foam.