A flame-retardant rigid polyurethane foam contains a flame retardant, the foam having a ratio of the maximum peak intensity ratio (P1) of the foam after moist heat treatment of the foam for one week at a temperature of 80° C. and a humidity of 85% to the maximum peak intensity ratio (P2) of the foam before this moist heat treatment of 85% or more (P1/P2x100). The P1 and P2 each refer to the ratio of the maximum peak intensity of 1390 to 1430 cm.sup.−1 to the maximum peak intensity of 1500 to 1520 cm.sup.−1 when the infrared absorption spectrum is measured at a position 5 to 10 mm from the surface of the foam, and the average intensity of 1900 to 2000 cm.sup.−1 is adjusted to zero.

Isopropylidenediphenol-based polyether polyols, processes for their production, foams produced using such isopropylidenediphenol-based polyether polyols, such as PUR-PIR rigid foams, as well as to processes for producing such foams. The polyether polyols include: (a) an alkoxylate of 4,4′-isopropylidenediphenol; (b) an alkoxylate of 2,4′- and/or 2,2′-isopropylidenediphenol; (c) an alkoxylate of components comprising structural elements which are derived from phenol, acetone and/or isopropylidenediphenol, but which are not isomers of isopropylidenediphenol; and (d) an alkoxylate of a diol that has a molecular weight less than the molecular weight of isopropylidenediphenol and that does not contain structural elements derived from phenol, acetone and/or isopropylidenediphenol.

A surfactant and a method of forming the surfactant having the formula (I) where a is an integer from 1 to 10, b is an integer from 0 to 10, R.sub.1 is —CH.sub.3 or —H, n is an integer from 0 to 20, and R.sub.2 is a moiety selected from the group consisting of (II), (III), (IV), (V), (VI), (VII) or (VIII) where m is an integer from 0 to 4. The surfactant can be used in a method for preparing a rigid polyurethane foam.

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The invention relates to a method for producing foamed molded bodies comprising the steps of A) providing a mold, and B) introducing a foam-forming reaction mixture into the mold under variable pressure of injection,
wherein the method is characterized in that
the foam-forming reaction mixture has a fiber time of ≧20 s to ≦60 s.

A polyester polyol is formed in a polycondensation reaction between an aromatic dicarboxylic acid, a polyol, and an epoxy compound having a straight chain alkyl or alkenyl group having at least six carbon atoms. The polyester polyol exhibits excellent compatibility with hydrocarbon blowing agents. As such, it is a useful component in rigid polyurethane foam formulations that are contain hydrocarbon blowing agents.

What are described are (a) a composition suitable for production of rigid polyurethane foam, comprising at least one isocyanate component, a polyol component, optionally a catalyst that catalyses the formation of a urethane or isocyanurate bond, optionally blowing agents, where the composition additionally comprises hydrocarbons HC, polyether-modified siloxane and optional polyalkylsiloxane, (b) a process for producing rigid polyurethane foam using hydrocarbons HC, polyether-modified siloxane and optional polyalkylsiloxanes, (c) the rigid polyurethane foam thus obtainable and (d) the use thereof.

A rigid polyurethane foam formulation comprising a polyester polyol having a hydroxyl number of from 150 to 600 mg KOH/g and a functionality of at least 2, a blowing agent comprising water and an auxiliary blowing agent, a non-silicone organic surfactant, greater than 0.1% to less than 3.7% of a cyclic siloxane, by weight based on the total weight of the foam formulation, a catalyst, and optionally a flame retardant; and a polyisocyanate; such that the isocyanate index is in the range of from 100 to 500, a rigid polyurethane foam formed from the foam formulation; and a method of forming a rigid polyurethane foam.

A rigid polyurethane foam which is a polymerization product of a composition including a concentrated acid hydrolytic lignin, a polyol, and an isocyanate, and a method of preparing the rigid polyurethane foam.

The present disclosure relates to improving insulation properties of foams by employing an azeotropically-modified blowing agent that preserves or improves R-value at various temperatures such as lower than ambient temperatures (below 24° C.). The present disclosure also provides foams with improved long-term thermal resistance (LTTR).

A composition for preparing polyisocyanurate and polyurethane foams is provided, comprising A) an isocyanate-reactive component, B) a polyisocyanate component and C) a branched siloxane comprising at least three trimethylsiloxy groups. A method for preparing the polyisocyanurate and polyurethane foams, and foams prepared thereby are also provided.