Polyol Component Research Articles

The Modification of Polyurethane Foams Using New Boroorganic Polyols: Obtaining of Polyols with the Use of Hydroxypropyl Urea Derivatives

Methods of synthesis of new prospective polyol components for obtaining of polyurethane foams of reduced combustibility using eco-friendly substrates have been presented. With this end in view, N,N′-bis(2-hydroxypropyl)urea was esterified with boric acid and next the hydrogenborate obtained was hydroxyalkylated by the excess of propylene carbonate. The influence of the way of esterification on the hydroxypropyl derivatives of borate substituted urea properties has been investigated. Esterification was run in the presence and in the absence of solvent. According to instrumental analysis, the characteristic of hydrogenborates obtained in both methods was found to be similar. The hydroxypropyl derivatives of borate substituted urea show similar spectral characteristics and thermal stabilities and differ slightly in molar masses, by-product contents, and physical properties, particularly viscosities. The properties of these derivatives were assessed paying special attention to their application as the polyol components of polyurethane foams. Hydroxypropyl urea derivatives, modified by boric acid, show changes in physical properties with temperature, similarly to typical polyols used for obtaining of polyurethane foams.

Effect of the boron presence on the properties of polyurethane foams obtained with hydroxypropyl derivatives of oxamide as the polyol components

Abstract The results of esterification of N,N'-bis(2-hydroxypropyl)oxamide (BHPOD) with the use of boric acid (BA) have been described. Subsequently hydroxypropyl derivatives of oxamide (OD) modified with boron as products of the reaction of BHPOD esterified boric acid with an excess of propylene carbonate (PC) have been obtained. Foamed polyurethane materials received with the use of these derivatives as polyol components and diisocyanate 4,4'-diphenylmethane exhibited higher thermal stability and compressive strength compared to the foams obtained with hydroxypropyl derivatives of OD which do not contain boron.

Lignin-based rigid polyurethane foams with improved biodegradation

Rigid polyurethane (RPU) foams have been synthesized using lignin-based polyols obtained by oxypropylation of four distinct lignins (Alcell, Indulin AT, Curan 27-11P, and Sarkanda). Polyol formulations with two lignin/propylene oxide/catalyst content (L/PO/C) ratios were chosen (30/70/2 and 20/80/5). RPU foams have been prepared with a polyol component that incorporates the lignin-based one at contents ranging from 25 to 100%. A 100% commercial polyol-based (Lupranol® 3323) RPU foam was also prepared and used as the reference. RPU foams were characterized in terms of density, compressive modulus, and conductivity. Cell morphology and size estimation were accessed by scanning electron microscopy. Moreover, biodegradation of the Alcell- and Indulin AT-based foams was evaluated using respirometry tests in liquid and solid media. The Alcell- and Indulin AT-based polyols together with the 20/80/5 Curan 27-11P-based one led to RPU foams with properties quite similar to those of the reference homolog. Biodegradation seems to be, particularly, favored if using Indulin AT-based polyols mixed with Lupranol® 3323.

Polyurethane foams based on modified tung oil and reinforced with rice husk ash I: Synthesis and physical chemical characterization

A chemically modified tung oil was used as the main polyol component in the formulation of viscoelastic (low resilience) polyurethane foams. Rice Husk Ash (RHA), a residue from the rice process industry, was chosen to be incorporated as rigid filler in these materials because of its high silica content. Water was used as blowing agent in order to increase the green nature of the reinforced foams. Physico-chemical and thermal properties of the neat and reinforced foams were measured and analyzed. RHA addition leads to noticeable changes in several properties, mainly thermal conductivity, density and foam morphology, even at the low filler content used in this work. Although the thermal stability was almost unaffected by ash content, a stabilizing effect of the inorganic filler was identified, since the residual char was higher than predicted from theoretical calculations.

Effect of the boron presence on the properties of polyurethane foams obtained with hydroxypropyl derivatives of oxamide as the polyol components

Effect of the boron presence on the properties of polyurethane foams obtained with hydroxypropyl derivatives of oxamide as the polyol components

Thermal stability of polyurethane materials based on castor oil as polyol component

Preparation of the series of polyurethane elastomers and its nanocomposites from castor oil (a vegetable triglyceride) and different isocyanates (aromatic: toluene diisocyanate, TDI and aliphatic: isophorone diisocyanate, IPDI) is described. The synthesis was carried out in bulk and without catalyst by a one-step reactive process. Different elastomers were prepared by using several stoichiometric imbalances. For polyurethane nanocomposites based on TDI, titanium(IV) oxide nanoparticles was used. The thermal properties of the materials are discussed on the basis of simultaneous TG-DSC measurements results and TMDSC data. TMDSC results show that T g increases with increasing r = NCO/OH ratio. Namely, with increasing NCO/OH ratio the cross-linkage density increases and as a consequence, the chain mobility decreases, resulting in a higher T g. It was estimated that the T g of the samples decreased as the nanofiller content increased due to the changes in the segmental mobility in polyurethane materials. Thermal data refers to increased stability of nanocomposites compared with that of the unfilled elastomers.

New foamed plastic based on polyetherols obtained from 6‐aminouracil, ethylene carbonate, and propylene oxide

AbstractPolyetherols with 1,3‐pyrimidine ring including both oxyethylene and oxypropylene groups were obtained in reactions of 6‐aminouracil with ethylene carbonate and propylene oxide. The structure of the products was analyzed by spectral methods. Some physical properties of polyetherols were investigated. The polyetherols were used as polyol components to obtain polyurethane foams. Some properties of the foams such as apparent density, absorption of water, linear dimensions stability, thermal resistance, and compression strength were investigated. The foams obtained show an improved thermal stability. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

The investigation reaction kinetic for polyurethanes based on different types of diisocyanate and castor oil

The formation of polyurethanes based on vegetable oils is very complex and thus for industrial production of this materials it is important to determine the optimal temperature for polymerisation and finally to obtain materials with the proper mechanical properties. The goal of this work was to assess the kinetic of catalysed and noncatalysed reactions for polyurethanes based on castor oil as the polyol component and different types of diisocyanates. Due to the presences of hydroxyl groups on ricinoleic acid, castor oil is suitable for polyurethane preparation. The differential scanning calorimetry has been employed to study the polyurethane formation reaction using Ozawa isoconversion method. It was estimated that the catalyst addition decreases the activation energy. The highest reduction of activation energy was observed for the reactive systems with hexamethylene diisocyanate. Validity of obtained kinetic model was examined by FTIR spectroscopy following the apsorption of reactive groups. Obtained results of mechanical characteristics of the polyuretahane networks (with different NCO/OH ratio) confirmed that applied method could be used for prediction of optimal reaction condition in polyurethane networks synthesis.

Obtaining of polyurethane foams with contribution of hydroxyalkylation products of oxalamide with alkylene carbonates and their properties

AbstractReaction products of Oxalamide (OD) with a 8- and 12-molar excess of ethylene carbonate (EC) and propylene carbonate (PC), characterized by an enhanced thermal stability due to the presence of Oxalamide arrangement, were used as polyol components for obtaining foamed polyurethane plastics. As an isocyanate agent diphenylmethane-4,4’-diisocyanate was used. The obtained new foamed polyurethane plastics are characterized by a slight water uptake, good stability of dimensions and an enhanced thermal stability.

Polyurethane foams with the contribution of products of hydroxyalkylation of N,N′‐bis(2‐hydroxyalkyl)oxamides with alkylene carbonates—obtaining and properties

AbstractIn the reactions of N,N′‐bis(2‐hydroxyethyl)oxamide (BHEOD) with an excess of ethylene carbonate (EC) and N,N′‐bis(2‐hydroxypropyl)oxamide (BHPOD) with an excess of propylene carbonate (PC), the hydroxyethoxy and hydroxypropoxy derivatives of oxamide (OD) were obtained, respectively, distinguished by an increased thermal stability. First time, these derivatives were used as polyol components to obtain foamed polyurethane plastics with the contribution of 4,4′‐diisocyanate diphenylmethane (MDI). The rigid polyurethane foams of a slight water uptake, good stability of dimensions, enhanced thermal stability, and compression strength were obtained. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Biosynthesis of Silver Nanoparticles Using Sun-Dried Mulberry Leaf

The biosynthesis of silver nanoparticles (AgNPs) has been successfully conducted by reduction of silver nitrate with sun-dried mulberry leaf. Such AgNPs have been characterized by UV-visible spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, high-resolution transmission electron microscopy (HRTEM) and atomic force microscopy (AFM). The results showed that such dispersed, uniform and spherical AgNPs would not aggregate under high-concentration NaCl solution and have good antibacterial activity. It was suggested that the polyol components (such as polyhydroxylated alkaloids) and protein residues of mulberry leaf should be mainly responsible for the stabilization of AgNPs. Such AgNPs produced by the environmentally friendly method have the potential for use in antibacterial and medical applications.

Modification of PUR-PIR foams by boroorganic compound prepared on the basis of di(hydroxymethyl)urea

The method for preparation of boroorganic compound with application of N,N′-di(methyleneoxy-3-hydroxypropyl)urea and boric acid has been described. Then, the borate prepared was characterized mainly in the terms of its usability as a polyol component and fire retardant for production of the rigid polyurethane-polyisocyanurate foams. Method of preparation, the determination of foaming parameters, physicomechanical and fire properties of PUR-PIR foams as well as the results of tests have been presented. The recipe for foam preparation was modified by application of physical and chemical method of foaming. On the basis of the results, it was found that application of the new compound in recipe for production of foams is very favourable. The rigid foams obtained are characterized by lower brittleness, higher compressive strength, lower thermal conductivity and considerably lower flammability in comparison with a standard foam.

Polyetherols from melamine cyanurate and ethylene carbobate - synthesis and application

Polyetherols from melamine cyanurate and ethylene carbobate - synthesis and application The results of the study on the reactions of melamine cyanurate with ethylene carbonate were presented. As a result of the reactions, polyetherols containing thermostabile 1,3,5-triazine and perhyroxo-1,3,5-triazine rings in their structure were obtained. Basic physical properties such as density, viscosity, hydroxyl number, weight changes were measured. The polyetherols were applied as a polyol component to receiving of thermoresistant polyurethane foams. Some of the properties of the obtained foams were investigated. The value of the apparent density is between 51 and 71 kg/m3, compressive strength 222-356 kPa and the content of the open pores between 14-33%. Thermal resistance was also studied by means of the TGA method. It was found that oxygen index of the selected compositions is between 20-22%.

Analysis of the reaction course of oxamide and N,N′-bis(2-hydroxypropyl)oxamide with propylene carbonate

Studies on obtaining and hydroxypropyl properties of oxamide (OD) derivatives with contribution of OD and N,N′-bis(2-hydroxypropyl)oxamide (BHPOD) were carried out. As a hydroxyalkylating agent, the propylene carbonate (PC) was used. Hydroxypropylating with OD proceeds with a partial preservation of carbonate groups in the structure of products, and during the reaction, a partial dimerization of hydroxypropoxylene derivatives of OD occurs. The obtained hydroxypropoxy derivatives of OD are distinguished by an increased thermal stability. Hydroxypropoxy derivatives of OD are expected to find application as polyol components for the manufacture of thermally stable foamed polyurethane plastics. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

New polyol for production of rigid polyurethane‐polyisocyanurate foams, Part 2: Preparation of rigid polyurethane‐polyisocyanurate foams with the new polyol

AbstractThe method of preparation, determination of foaming parameters, and methods for the determination of physicochemical properties of polyurethane‐polyisocyanurate (PUR‐PIR) foams prepared with the use of N,N′‐di(methyleneoxy‐2‐hydroxyethyl)urea and boric acid derivatives are presented in this paper. It was found that application of the borate as a polyol component and simultaneously as a flame retardant in the recipe for production of PUR‐PIR foams was very favorable. The foams prepared were characterized by reduced brittleness, higher compressive strength and content of closed cells, as well as considerably lower flammability in comparison with standard foam. The results show that the new polyol prepared on the basis of N,N′‐di(methyleneoxy‐2‐hydroxyethyl)urea and boric acid can be applied for production of rigid PUR‐PIR foams, and it improves their physicochemical properties. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

New Polyol for Production of Rigid Potyurethane-polyisocyanurate Foams Part 2: Preparation of Rigid Polyurethane-polyisocyanurate Foams with the New Polyol

Method of preparation, the determination of foaming parameters and methods for the determination of physicochemical properties of PUR-PIR foams prepared with the use of N,N'-di(methyleneoxy-2-hydroxyethyl)urea and boric acid derivative has been presented in this paper. It was found that application of the borate as a polyol component and simultaneously as a flame retardant in the recipe for production of polyurethane-polyisocyanurate foams (PUR-PIR) was very favourable. The foams prepared were characterized by reduced brittleness, higher compressive strength and content of closed cells as well as considerably lower flammability in comparison with standard foam. The results show that the new polyol prepared on the basis of N,N'-di(methyleneoxy-2-hydroxyethyl)urea and boric acid can be applied for production of rigid polyurethane-polyisocyanurate foams and it improves their physicochemical properties.

Properties of clear polyurethane films modified with a fluoropolymer emulsion

An emulsion of a fluoroethylene vinyl ether polyol, Lumiflon FE-4400, was incorporated into clearcoats of two-part water-based military polyurethane topcoats. This additive was mixed with the aqueous dispersion polyol component. The polyol component was then mixed with the isocyanate component with a high speed disperser to properly mix the reactants. Films were prepared by drawing down the dispersion onto glass substrates using a 4-mil stainless steel Bird applicator. After drying at ambient conditions the films were removed from the glass for analysis. As measured using X-ray photoelectron spectroscopy, Lumiflon FE-4400 segregated to the surface providing significant fluorine enrichment at the air interface, as high as 90 times the bulk concentration. Although increasing the concentration of Lumiflon FE-4400 increased the surface concentration, the ratio of surface concentration to the bulk concentration decreased. As expected, water contact angle increased approximately in a linear fashion with the surface fluorine concentration. At 1–5 wt% added Lumiflon FE-4400, the physical and mechanical properties were not significantly affected. However, addition of Lumiflon FE-4400 at or above 10% of polyol fraction significantly reduced the glass transition temperature, modulus, crosslink density, strength, toughness and weathering resistance. Phase contrast microscopy showed that the morphology of these films went from being uniform to having distinct aggregates that increased in size and number as fluorinated polyol fraction increased, likely explaining the reduction in film properties. Accelerated weathering of pigmented coatings was also performed. Although fluorinated resins typically improve weathering resistance of coatings, in this study, increasing the Lumiflon FE-4400 content decreased the weathering resistance as a result of the ethoxylation of the fluorinated additive necessary to produce an aqueous fluoropolymer emulsion.

Modification of PUR-PIR foams by boroorganic compound obtained on the basis of bis(hydroxymethyl)urea

A method for the preparation of a boroorganic compound with the application of N,N'-- bis(methyleneoxy-2-hydroxyethyl)urea and boric acid has been presented. The prepared borate was evaluated mainly in respect of its applicability as a polyol component and antipirene for the production of polyurethane-polyisocyanurate foams. The preparation method, the determination of foaming parameters and methods for the determination of physicomechanical properties and flammability of the PUR-PIR foams were described and the results were presented. On the basis of studies, it was found that application of the new compound in the preparation of foams was advantageous. The rigid foam obtained was characterized by reduced brittleness, higher ultimate compressive strength and a significantly reduced flammability in comparison with standard foam.

Nowy poliol boroorganiczny do produkcji sztywnych pianek poliuretanowo-poliizocyjanurowych Cz. II. OTRZYMYWANIE SZTYWNYCH PIANEK POLIURETANOWO-POLIIZOCYJANUROWYCH Z ZASTOSOWANIEM NOWEGO POLIOLU BOROORGANICZNEGO

The conditions of polyurethane-polyisocyanurate (PUR-PIR) foams preparation with use of new boroorganic compound as polyol are presented. The new compound is a product of the reaction of N,N'-di(methyleneoxy-3-hydroxypropylo)urea with boric acid. The results of determination of foaming process parameters as well as of investigation of the foams' functional properties are given. The results show that the use of borate obtained as polyol component and simultaneously as fire retardant in the production of PUR-PIR foams is very beneficial. The rigid foams obtained are less brittle, show better compression strength and higher content of close cell as well as much lower flammability in comparison with control sample. The results show that the new polyol described improves functional properties of the polymers so could be effectively use in the production of polyurethane-polyisocyanurate foams.

Halogen-free, low flammability polyurethanes derived from deoxybenzoin-based monomers

Two novel deoxybenzoin-containing monomers, a diisocyanate and a diol, were synthesized and used to prepare polyurethane materials and foams. 4,4′-Diaminodeoxybenzoin was prepared by Ullmann coupling of 4,4′-dibromobenzil with tert-butyl carbamate. Reduction of one of the carbonyl groups, and t-Boc deprotection, gave the aromatic diamine, which was converted to 4,4′-deoxybenzoin diisocyanate (DBDI) with triphosgene. DBDI was then used to prepare two different polyurethanes, one by reaction with 1,3-propanediol, and the other by reaction with deoxybenzoin diol. The polyurethanes obtained from these reactions displayed low heat release capacity (HRC) values relative to conventional polyurethanes prepared from 4,4′-methyldiphenyl diisocyanate (MDI) and 2,4-toluene diisocyanate (TDI). Polyurethanes prepared in this study displayed HRC values as low as ∼130 J g−1 K−1, and char yields as high as ∼40%. In addition, deoxybenzoin-based oligomers containing hydroxyl end groups were also synthesized and used to prepare polyurethane foams that displayed markedly lower HRC values, and higher char yields, than conventional polyurethane foams, which burn readily and drip. Taken together, the integration of deoxybenzoin moieties into the diisocyanate or polyol component of the polymer structure is found to lower heat release rates and reduce flammability in the absence of any added flame retardant, such as halogenated compounds that represent health and environmental hazards.