Polyol Component Research Articles

Photobase‐generating new polyurethanes with oxime–urethane groups in the main chain

AbstractNew polymeric photobase generators containing oxime–urethane groups were prepared by the polyaddition reaction of 2,4‐tolylene diisocyanate with terephthalaldehyde dioxime in the presence or absence of a polyol component to study the ability of these polymers to generate amines through the photolysis of oxime–urethane linkage. The amines induced the crosslinking of poly(glycidyl methacrylate), as proved by the variation of the amount of the insoluble fraction of polymer films with the heating temperature and/or irradiation time. UV and IR absorption spectra indicated that the thermal crosslinking of poly(glycidyl methacrylate) was catalyzed by the photogenerated amines. The photobehavior of the polymers was followed by a reduction of the absorption band at 290 nm, which was characteristic of oxime–urethane groups, as a function of the UV irradiation time. Blue fluorescence was visualized by the treatment of irradiated films with fluorescamine. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2324–2332, 2004

Thermally stable hybrid foams based on cyclophosphazenes and polyurethanes

Two cyclotriphosphazenes, containing OH groups, have been synthesized: hexakis[ p-(hydroxymethyl)phenoxy]cyclotriphosphazene (PN6), with six hydroxyl groups, and 2,2-di-[ p-(hydroxymethyl)phenoxy]-4,4,6,6,-bis[spiro(2′,2″-dioxy-1′,1″-biphenyl)cyclotriphosphazene (PN2) with two hydroxyl groups. They were used in the preparation of modified rigid polyurethane foams as OH containing compounds, alone or in mixtures with polyol components. The thermal stabilities of the resultant hybrid foams were analysed using thermogravimetric analysis (TGA), in inert (nitrogen) and oxidizing (air) atmosphere. The fire behaviour has been investigated by means of oxygen index (LOI) tests. The results showed that the introduction of increasing amount of cyclotriphosphazene in foams leads to a significant improvement of the thermal stability, both in nitrogen and in air. Improvement has also been observed in the fire behaviour of modified foams, particularly for the foams containing cyclotriphosphazene PN2.

CHARACTERIZATION OF ALKYD PAINT MEDIA BY GAS CHROMATOGRAPHY-MASS SPECTROMETRY

Alkyd resins, manufactured from polyols, polybasic acids and monobasic fatty acids, may be categorized as oil-modified polyesters. Resin formulators customize the drying and performance properties of alkyd paints either by varying the type and/or stoichiometric proportions of the reactants, or by adding modifiers (for example, styrene, acrylics and isocyanates) during the manufacturing processes. Alkyd resins have been widely used as binding media in virtually all types of paints since the 1940s, having replaced drying oils in many industrial applications. Identification of alkyd paint media is most often accomplished using Fourier-transform infrared spectroscopy (FTIR) or pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS), yet these techniques are semi-quantitative at best. Two GC-MS procedures have been developed for the quantitative analysis of polyol, dibasic acid and fatty acid components. Results from the analysis of various alkyd paints and unpigmented media demonstrate the utility of the procedures in characterizing alkyd paint media.

PTT plant to use advanced anti-pollution methods

Since polyol is one of the major components in polyurethane foam synthesis, introducing renewably sourced polyols in the foam formulation leads to materials with high renewable carbon content. A series of flexible polyurethane foams with variations in polyol composition were synthesized with castor oil based Lupranol Balance® 50 polyether polyol and corn based polytrimethylene ether glycol mixtures. Water was used as the unique and eco-friendly blowing agent. The effect of the relative amount of each polyol on the structure and properties was analyzed by optical microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, tensile and compressive tests, dynamic mechanical analysis and atomic force microscopy. The average molecular weight and hydroxyl number of the polyol components showed to influence the foaming reaction and hence the structure and properties of the polyurethane foam. The newly developed peak force quantitative nano-mechanics technique was used to map the elastic modulus values of foam cell struts and it seemed to be adequate to assess the purity of the different phases.

Preparation of partially hydrolyzed oligo(vinylacetate) as polyol for polyurethane formation

AbstractPolyols based on oligo(vinylacetate) were synthesized using a convenient one‐pot, two‐step process. Polymerization of vinylacetate was performed in 2‐propanol as a chain‐transfer agent using di‐tert‐butylperoxide as a free‐radical initiator. Saponification of the oligomers was performed in both tetrahydrofuran and 2‐propanol using stoichiometric amounts of methanol in the presence of a basic catalyst. Well‐defined oligo(vinylacetate‐co‐vinylalcohol) polyols with a degree of polymerization below 12 and a hydroxyfunctionality smaller than 4 were obtained. Oligo(vinylacetate‐co‐vinylalcohol) was used as a polyol component in the formation of polyurethanes. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2085–2092, 2002

Aminolysis and aminoglycolysis of waste poly(ethylene terephthalate)

This paper describes the chemical degradation of waste poly(ethylene terephthalate) (PET) with polyamines or triethanolamine, the characteristics of the products, and a search for ways to use these products. Solvolysis of the polymer ester bonds was caused by diethylenetriamine, triethylenetetramine, and their mixtures, as well as mixtures of triethylenetetramine and p-phenylenediamine or triethanolamine. Products of aminolysis or aminoglycolysis of PET obtained in reactions performed at 200–210°C (with a molar ratio of the recurrent polymer unit to amine of 1 : 2) have been characterized using nuclear magnetic resonance (NMR). Viscosity and hydroxyl number measurements have been done for PET/triethanolamine products. Substances from aminolytical reactions with polyamines were tested as hardeners for liquid epoxy resins, and the product of polymer aminoglycolysis with triethanolamine was tested as an epoxy resin hardener, e.g., for water-borne paints, and a polyol component for rigid polyurethane foams. The compositions of epoxy resin hardeners have been characterized using DSC and rheometry. Comparative analyses of the hardened epoxy materials have been done on the basis of glass temperature and mechanical properties data, as well as some specific properties of the coating materials and rigid polyurethane foams.

Influence of weathering on physical properties of clearcoats

In this paper investigations concerning the weatherability performance of different clearcoat systems (1K, 2K) with various aromatics concentration in the polyol components will be presented. The analyses resulted after each 100 h accelerated weathering in a period of total 1000 h. Chemical degradation processes were analysed by means of FT-IR spectroscopy. For the physical investigations were used: dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), investigation of the surface topography, contact angle measurements to determine the surface tension and gloss measurements. Especially, the mechanical investigations proved the changes in properties as remarkably suited. Already after a short exposure time these methods yielded information about the weathering behaviour of the investigated clearcoat systems.

Glycolysis of polyurethane foams and elastomers

Optimum conditions for the glycolysis of polyurethane flexible foams and elastomers are reported. The crude, two-phase liquid reaction mixture was separated and the upper phase was used as the polyol component of an industrial adhesive mixture. During glycolysis the formation of carbon dioxide was recognized and quantified. On the basis of this new finding a novel reaction mechanism is proposed for the glycolysis of polyurethanes.

MALDI-MS and colorimetric analysis of diisocyanate and polyol migrants from model polyurethane adhesives used in food packaging

The identification of the migrants, into food simulants, from a series of polyurethane adhesives used in the manufacture of plastic film laminates for use in common food packaging is described. Commercial materials, based on four different model adhesive systems, were prepared by an industrial collaborator. The MALDI-MS fingerprint patterns of the three polyether and one polyester polyol components of these adhesives were obtained for reference purposes. The decrease in the level of diisocyanate as a migrant versus time after lamination was confirmed by colorimetric measurements. The migration of the standard polyol samples through polyethylene pouches into water at 70 degrees C has been demonstrated and also the attenuation effect for different polyols. Cured laminates in the form of pouches were used to carry out the migration experiments into distilled water, inside the pouch, at 70 degrees C over a period of 2 h. Comparison of the migration results from the food packaging laminates with those from the polyethylene film confirmed the migration of unreacted polyol components for the polyether-based systems. Cyclic oligomers from the polyol starting materials were identified as the migrants from the polyester-based adhesive.

Rigid polyurethane foams with poly(ethylene terephthalate)/triethanolamine recycling products

A product of the chemical degradation of poly(ethylene terephthalate) (PET) with triethanolamine was used as a polyol component for rigid polyurethane foam synthesis. Miscibility of the product with water, some polar organic solvents and commercial polyols was investigated. Viscosities of the product as a function of temperature as well as in solutions with water and the polyols were examined. The PET chemical recycling product was used instead of the commercial polyol in rigid polyurethane foam formulation. Technological times were defined for the process of the foam synthesis. These foams have density of about 30 kg/m3, compression strength in a range of RC = 80–160 kPa and thermal conductivity coefficient λ = 0.028–0.038 W/m K. Rigid polyurethane foams prepared from the product of PET degradation with triethanolamine can be considered as insulation materials. Copyright © 1999 John Wiley & Sons, Ltd.

Formation of polyurethane membranes by immersion precipitation. i. liquid-liquid phase separation in a polyurethane/DMF/water system

Liquid–liquid phase separation phenomena of polyurethane/DMF/water were studied. Two polyurethanes having different hydrophobicity were synthesized by varying the polyol components. The cloud-point curves for the ternary system of polyurethane/DMF/water were determined by the titration method. A small amount of water is needed to induce liquid–liquid demixing, and the region of the homogeneous phase is enlarged with increased hydrophilicity of the polyurethane. We measured the interaction parameters, and calculated the binodal and spinodal curves based on the thermodynamics of polymer solutions. The light transmission experiment showed that precipitation time increased with the higher content of DMF in a coagulation bath. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 2377–2384, 1999

Aqueous Ethylenediamine Dihydroxo Palladium(II): A Coordinating Agent for Low- and High-Molecular Weight Carbohydrates

An aqueous solution of [(en)Pd(OH)2] (Pd-en) forms 1,2and 1,3-diolato complexes on reaction with polyols. Three crystalline palladium(ii) complexes have been isolated and characterized with anhydroerythritol (AnEryt), 1,6-anhydro-b-d-glucose (1,6AnGlc, levoglucosan), and sucrose (Suc) as the polyol components, namely [(en)Pd(AnErytHy2)] 4 H2O (1), [(en)Pd(1,6AnGlc2,4Hy2)] H2O (2) and [(en)2Pd2(Suc1,3,3',4'Hy4)] 11 H2O (3). Pd-en acts as a coordinating solvent for cellulose; the polysaccharide anhydroglucose units (GlcC) form [(en)Pd(GlcC2,3Hy2)] entities on dissolution. The palladium-binding sites of the saccharides may be recognized by 13C NMR spectroscopy in the case of 1,2-diolic chelator groups, which exhibit a downfield, coordination-induced shift of the two diolato carbon atoms of about 10 ppm. Slightly yellow, viscous solutions of cellulose in Pd-en, which are largely insensitive to oxidative degradation, were characterized by light scattering (LS). Analysis of the chain conformation by LS supports the significance of chain stiffening by intramolecular interresidue hydrogen bonds of the type O6' ± H O2y in the molecularly dispersed and entirely metallated cellulose strands. The flexibility and energy of the hydrogen bond were investigated by density functional theory (DFT) calculations.

Development of a rigid polyurethane foam from palm oil

The reactions between polymeric diphenyl methane diisocyanate (polymeric MDI) and conventional polyols to produce foamed polyurethane products are well documented and published. Current polyurethane foams are predominantly produced from these reactions whereby the polyol components are usually obtained from petrochemical processes. This article describes a new development in polyurethane foam technology whereby a renewable source of polyol derived from refined–bleached–deodorized (RBD) palm oil is used to produce polyurethane foams. Using very basic foam formulation, rigid polyurethane foams were produced with carbon dioxide as the blowing agent generated from the reaction between excess polymeric MDI with water. The foams produced from this derivatized RBD palm oil have densities in excess of 200 kg/m3 and with compression strengths greater than 1 MPa. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 509–515, 1998

The Use of Principal Component Analysis to Classify PDMS Surfactants Used to Make Rigid Polyurethane Foams Based on Their Dynamic Surface Tension Characteristics

Polydimethylsiloxane surfactants are well known in the polyurethane industry. They play a vital role in the manufacture of both rigid and flexible foams. In order to achieve the phaseout of CFCs, as prescribed in the Montreal protocol, new blowing agents have been developed to make polyurethane foams. This has been accompanied by changes in the composition of the foam forming material including the silicone surfactants. This article describes a method for measuring the dynamic surface tension behavior of these silicone surfactants in model liquids representative of the polyol component in the foam forming mixture. The different dynamic surface tension characteristics of commercially available silicone surfactants are reported. In a second stage these data are analyzed using a chemometrics technique called principal component analysis. This allows the classification of the various surfactants in several subsets, each characterized by a specific dynamic surface tension behavior. The combined method of dynamic surface tension measurements and principal component analysis allows fast screening of surfactants used in the polyurethane industry.

New Polyester Resin for Electrophotography Toner Having Excellent Fixing Properties

This present research relates to a toner comprised the new polyester resin for electrophotography which is used in copiers, printers, fax machines or multifunction devices utilizing heat-roll fixing.This polyester resin was prepared by synthesizing a linear polyester resin having low molecular weight peak top in a range of 1×103 to 1×104, and then cross-linking with dicarboxylic acid component having long chain structure and polyol component having four hydroxyl groups.This resin has a low molecular weight peak top and widened molecular weight distribution. The toner comprised this resin showed excellent fixing properties at low temperature without losing anti-offset up to 220°C. Then, it was concluded that the polyester resin is an useful toner binder for the contact heated fixing process.

Recycling of Rigid Polyurethane Articles and Reformulation into a Variety of Polyurethane Applications

Recycling of thermoset polymeric materials offers a unique challenge. It is often assumed that thermoset materials in general, and polyurethanes specifically, are not recyclable or only recyclable in limited applications as regrind. Herein, we report the recyclability of polyurethane materials by glycolysis and recovery of a polyol. The glycolysis technology utilized is unique in that the residual free amine content is very low, and the entire reaction mixture is useful as a urethane polyol. This is in contrast to other glycolysis technologies that involve separation steps and ultimately in the production of other more hazardous waste streams. The reaction proceeds at ambient pressure and moderate temperature obviating the need for highly sophisticated control mechanisms. The recyclate properties are relatively insensitive to the waste stream utilized, thus permitting the mixed waste streams as raw materials in the process. In this investigation, high density non-cellular rigid urethanes have been successfully glycolyzed and formulated into a variety of polyurethane systems. These include applications in energy management technology, as well as other rigid and semi-rigid applications. Inclusion of the recyclate shows little detriment to the physical properties of the resulting polyurethane in a variety of applications. An example of a closed loop recycling strategy is demonstrated in rigid insulating foam. A cyclopentane blown rigid polyurethane can be glycolyzed and the resulting polyol incorporated into the original system at up to 20% of the polyol component with excellent dimensional stability and thermal conductivity results. Up to 100% replacement shows little sacrifice in physical properties. Preliminary laboratory results also show excellent potential for both rigid insulation foam and high density, rigid, non-cellular polyurethanes to be amenable to the glycolysis process. This paper describes aspects of our efforts to meet the challenge posed by an increasing number of our customers to render polyurethanes readily recyclable.

Influence of structure of hydroxyl‐terminated maleopimaric acid ester on thermal stability of rigid polyurethane foams

AbstractA series of hydroxyl‐terminated maleopimaric acid esters (HTMAEs) and rigid polyurethane (PU) foams based on these HTMAEs were synthesized using chemically modified natural gum rosin and its derivative maleopimaric acid as raw materials. Thermal stability of these polyols and their corresponding rigid PU foams was studied by a thermogravimetric method and a dimensional stability measurement. It was shown that the thermal stability of the final foams was strongly dependent on the structure of their corresponding polyols. The thermogravimetric analysis curves of these rosin‐based rigid PU foams displayed two distinct regions of weight loss. It has been shown that at the initial stage of weight loss the process was dominated by polyol component degradation; the second stage was governed by isocyanate component degradation. © 1995 John Wiley & Sons, Inc.

Capillary Gas Chromatography Combined with Ion Trap Detection for Quantitative Profiling of Polyols in Cerebrospinal Fluid and Plasma

Polyol species in cerebrospinal fluid and plasma-ribitol, arabitol, xylitol, 1,5-anhydrosorbitol, myo-inositol, mannitol, sorbitol, and galactitol-simultaneously were quantitated by a capillary gas chromatography/ion trap (mass spectrometric) detection method. The details of the methodology are discussed and the results of analysis of polyols in healthy human subjects are reported. Microliter volumes of cerebrospinal fluid or plasma were mixed with internal standard (deuterium labeled myo-inositol), deproteinized, and evaporated to dryness. Polyols were acetylated in the presence of pyridine catalyst and washed with sodium bicarbonate solution and the acetate derivatives were recovered. Standard curve solutions were similarly treated. The polyol components were resolved on a capillary column bonded with 50% phenyl-50% methyl polysiloxane. Chemical ionization mass spectra for the acetate derivatives of polyols were generated in an ion trap using acetonitrile as reagent gas. Each polyol yielded a fragment ion in 100% abundance arising probably from the loss of one acetate moiety from the protonated molecule. These ions were monitored. The relative standard deviation (within-day) for quantitation of polyols was not greater than 8% for cerebrospinal fluid and 15% for plasma matrix. A polyol profile in cerebrospinal fluid and plasma was determined in healthy human subjects and a cerebrospinal fluid/plasma concentration ratio larger than 1.0 was found for all polyol species except 1,5-anhydrosorbitol and xylitol. This assay technique will be used to study the role of polyols in central nervous system diseases.

Advances in the Understanding of the Effects of Various Blowing Agents on Rigid Polyurethane Appliance Foam Properties

In the attempt to find alternative solutions for CFC-11, which is required to be phased out by the Montreal Protocol in the coming years, a number of different blowing agents were proposed and evaluated. These included several HCFCs, HFC-134a, pentane and totally water (chemically CO 2 ) blown foams. These substances differ widely in physical properties such as boiling point and solubility characteristics. None of them proved to be a direct drop-in replacement for CFC-11. In fact, all required reformulation of the polyol component in order to achieve acceptable processing conditions and resultant foam properties. A number of unexpected effects occurred which were not readily explained

Solid state NMR investigation of cationic polymerized epoxy resins

AbstractCationic UV‐polymerized resins, based on cycloaliphatic epoxides with aryl sulfonium salts as photoinitiators and polypropylene glycols of variable length as flexibilizers, have been investigated with respect to the network‐forming reactions and the morphology of the resulting polymers. The combination of UV‐curing and thermal postcure makes the chemical process complex and dependent on many variables, such as photoinitiator, exposure time, reaction temperature, and polyol components. Structure and curing of the epoxide were investigated by 13C CPMAS NMR. Morphology and domain sizes were studied by spin diffusion experiments using the novel “dipolar filter” technique for selective magnetization of mobile components.