The use of citric acid in the production of polyols for rigid PUR-PIR foams

Abstract

The article describes the method of obtaining new, cheaper compounds which can substitute polyols in the production of rigid polyurethane-polyisocyanurate foams (PUR-PIR). Rigid PUR-PIR foams were synthesized, using newly obtained tree compounds (citrates with hydroxyl groups): obtained with using catalyst (T-2-HHT ? K), without catalyst (T-2-HHT) and (T-5-HHT). New compounds (T-2-HHT ? K, T-2-HHT, T-5-HHT) were prepared from citric acid (1 mol) and glycols, respectively: butane-1.2-diol (3 mol and excess of 30 cm 3 ), butane-1.2-diol (3 mol), pentane-1.5-diol (3 mol) by the esterification reaction in the solution. The industrial Rocopol 551, used as polyol, was gradually substituted for the new compounds in the polyol premix in new foams. The three series of rigid polyurethane-polyisocyanurate foams based on T-2-HHT ? K, T-2-HHT, T-5-HHT have been synthesized (F1-F16) and W foam without new compound. Its properties have been determined according to the standards. It has been shown that the addition of T-2-HHT ? K, T-2-HHT, T-5-HHT to the foams affects the foams' density. The influence of the abovementioned compounds on foams' flammability, thermal properties and others was examined. A decrease in foams' brittleness by 6.9 % and in oxygen index by 24 % was observed. The examined retention was in the range of 80.9-96.5 %.

The Effect of Accelerated Aging Conditions on the Properties of Rigid Polyurethane-Polyisocyanurate Foams Modified by Cinnamon Extract

“…The smallest change in dimensions or the volume of foam is extremely important in using it as thermal insulation. Properly selected industrial insulation affects not only the saving of energy costs, but also the correct operation of the technological installation [19].…”

Polyurethane: Recent Engineering Contributions

“…A technique for the production of new cheaper components able to substitute polyols for the production of PU-polyisocyanurate foams is presented. The influence of the components on the foam flammability, thermal properties and other characteristics was examined [25].…”

Fully water-blown polyisocyanurate-polyurethane foams with improved mechanical properties prepared from aqueous solution of gelling/ blowing and trimerization catalysts

“…The literature contains many examples of self-dual Leonard pairs. For instance ated with an irreducible module for the Terwilliger algebra of the hypercube (see [4 Leonard pair of Krawtchouk type (see [10, De nition 6.1]); (iii) the Leonard pair ass module for the Terwilliger algebra of a distance-regular graph that has a spin mod bra (see [1,Theorem], [3,Theorems 4.1, 5.5]); (iv) an appropriately normalized to (see [11,Lemma 14.8]); (v) the Leonard pair consisting of any two of a modular Le De nition 1.4]); (vi) the Leonard pair consisting of a pair of opposite generators bra, acting on an evaluation module (see [5,Proposition 9.2]). The example (i) is a examples (iii), (iv) are special cases of (v).…”

“…In the case of polyisocyanurate modified with polyurethane (PIR-PUR) foams, attention has been paid to improve their properties. The modification methodology for PIR-PUR foams includes a choice of polyols (9)(10)(11)(12), catalysts (13) and blowing agents (14). Typical blowing agents for PIR-PUR foams are hydrochlorofluorocarbons (HCFCs), pentane or their mixtures with water.…”