Synthesis,characterization, and properties of polyols from hydrogenated terpinene–maleic ester type epoxy resin

Three kinds of polyfunctional polyols with hydroxyl values of 180–320 mg/g were prepared by the reaction of hydrogenated terpinene–maleic ester type epoxy resin with secondary amines (diethylamine, N‐methylethanolamine, and diethanolamine), and the chemical structures were characterized by Fourier transform infrared spectroscopy and NMR spectroscopy. These polyols were used in place of commonly used polyols to prepare two‐component polyurethanes when reacted with polyisocyanates. The crosslinking reactions of the polyols with polyisocyanate could be catalyzed by the tertiary amine groups included in the polyols, and the reaction rate was affected by hydrochloric acid and the polarity of the solvents. The mechanical, water‐resistance, and chemical‐resistance properties of the crosslinked products of the polyols were evaluated by standard tests, and the thermal properties were examined by differential scanning calorimetry and thermogravimetric analysis. The results show that these epoxy–urethane polymers, with glass‐transition temperatures (T_g's) in the range ?5 to 37°C, had good thermally resistant properties, and the temperatures at 5% weight loss were in the range 235–280°C. All of the polymers formed transparent, strong, flexible films, with good chemical‐resistance properties and excellent impact strengths of greater than 50 cm, a flexibility of 0.5 mm, adhesions of 1–2, and pencil hardnesses of HB–2H. The larger OH functionality and OH value of the polyol resulted in higher T_g and pencil hardness values and better alcohol resistance and thermal stability in the crosslinked product of the polyol. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

The effect of difunctional acids on the performance properties of polyurethane coatings

Hydroxyl-terminated polyesters are the most common polyols that are crosslinked through an isocyanate group. In this study, the polyester polyol resins were synthesized by using 1,4-cyclohexanedimethanol (1,4-CHDM) with the mixture of different diacids as 1,3-cyclohexanedicarboxylicacid (1,3-CHDA), 1,4-cyclohexanedicarboxylicacid (1,4-CHDA), isophthalic acid (IPA), adipic acid (AA), and azelaic acid (AZA). The solubility and viscosity of these polyester polyol resins were determined by using suitable solvent. All the polyester polyols were crosslinked with HDI isocyanurate and IPDI trimer to form polyurethane coating films. These films were evaluated for their mechanical, thermal, and chemical resistance properties. The studies on film characteristics reveal that the cycloaliphatic diacids afforded polyurethane with greater performance properties than that of aromatic and linear aliphatic diacids.     

Flexible,hard, and tough biobased polyurethane thermosets from renewable materials: glycerol and 10-undecenoic acid

The main theme of this work is to develop 100% biobased low viscous polyols from renewable resources. An epoxide compound (UA-GLY-E) was synthesized through esterification of glycerol and 10-undecenoic acid preceded by peroxidation. For the first time, UA-GLY-E was utilized as a building block in the generation of low viscous polyols and polyurethanes therefrom. The biobased polyols were synthesized by epoxide ring opening of UA-GLY-E with different nucleophiles, namely glycerol, water, and methanol. The advantage of these biobased polyols is their low viscosity and at the same time high functionality. These biobased polyols were further converted into poly(urethane–urea) coatings by reacting with methylene diphenyl diisocyanate. The impact of peripheral structural change in the polyols on the properties of polyols and their polyurethane coatings was studied. Flexible, hard, and tough thermosets have been prepared successfully from the same epoxy compound by altering the peripheral moiety in the polyol structure. Biobased polyurethanes prepared from glycerol and water-based polyols have shown better crosslinking density over the methanol-based polyol. Moreover, these biobased polyurethane films have shown good thermal stability, mechanical strength, and chemical resistance as well.     

Thermal stability and dynamic mechanical behavior of acrylic resin and acrylic melamine coatings

Acrylic polyols of different hydroxyl numbers consisting of hydroxy ethyl methacrylate, methyl methacrylate, butyl acrylate, and styrene were prepared by free‐radical solution as well as suspension polymerization techniques in the presence of benzoyl peroxide initiator. These polyols were crosslinked with butoxy methyl melamine at a ratio of 85 : 15 in the presence of acid catalyst. The thermal stability of polyols and their corresponding crosslinked films was studied by thermogravimetric (TG) technique. The Broido and Coats–Redfern methods were used to calculate the activation energy of thermal decomposition from standard TG curves. Dynamic mechanical thermal analysis was used to study the dynamic mechanical properties and determination of glass‐transition temperature of acrylic/melamine crosslinked films. The results indicate that the thermal stability of polyols and crosslinked films strongly depends on the hydroxyl number of the acrylic polyols. It was found that acrylic polyols synthesized by suspension polymerization methods upon crosslinking yield more thermally stable and flexible films than polyols prepared by solution polymerization methods. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 27–34, 2004     

Preparation and properties of poly(urethane acrylate) films for ultraviolet‐curable coatings

Four different UV‐curable poly(urethane acrylate)s were prepared through the reaction of two diisocyanates [i.e., toluene‐2,4‐diisocyanate (TDI) and isophorone diisocyanate (IPDI)] and two polyols [i.e., polycaprolactone triol (PCLT) and polycaprolactone diol (PCLD)], and they were characterized with Fourier transform infrared spectroscopy. The mechanical properties, thermal properties, and water sorption of the cured poly(urethane acrylate)s were also investigated with respect to the chemical structures of the polyols and diisocyanates. In comparison with linear PCLD–TDI and PCLD–IPDI, crosslinked PCLT–TDI and PCLT–IPDI with trifunctional PCLT showed relatively high thermal decomposition temperatures. The hardness and modulus of the UV‐cured poly(urethane acrylate) films, which were measured by a nanoindentation technique, were in the following increasing order: PCLD–IPDI ～ PCLD–TDI < PCLT–IPDI ～ PCLT–TDI. The pencil hardness was 3H for PCLT–IPDI and PCLT–TDI and HB for PCLD–IPDI and PCLD–TDI. Two urethane acrylates prepared from the trifunctional polyol showed better acid and alkali resistances than those made from the bifunctional polyol. These mechanical properties and chemical resistances may have been strongly dependent on the chain flexibility of the molecules and crosslinking density. Regardless of the functionality in the polyol, the change in the yellowness index showed a lower value in the poly(urethane acrylate) coating containing the aliphatic diisocyanate IPDI in comparison with the corresponding poly(urethane acrylate) with the aromatic diisocyanate TDI. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis and characterization of crosslinked polyurethane dispersions based on hydroxylated polyesters

Stringent environmental regulation has endowed dispersible coatings with excellent property profiles in industrial applications. In this aspect, aqueous polyurethane dispersions (PUDs) are of special interest. The present study reports on the synthesis of hydroxylated polyester (HP) based polyurethane polyols containing internal carboxyl group with different diisocyanates. These polyurethane polyols were partly acetoacetylated with ethyl acetoacetate to incorporate β‐ketoester in the polyurethane polyol backbone. The synthesized polyols were characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance, and differential scanning calorimetry. Polyurethane polyols and their acetoacetylated cousins were used to develop PUDs. Particle size of the reactive PUDs was evaluated by a particle size analyzer. PUDs were crosslinked with hexamethoxy methyl melamine and their film properties were studied by dynamic mechanical and thermal analyzers and thermogravimetric analyses. The effects of different diisocyanate and acetoacetylation on the stability of reactive dispersion and properties of the crosslinked films were evaluated. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 368–380, 2006     

Polyurethane networks from polyols obtained by hydroformylation of soybean oil

BACKGROUND: Vegetable oil‐based polyols are a new class of renewable materials. The structure of oil‐based polyols is very different from that of petrochemical polyols, and it is closely related to the structure of oils. The objective of this work was to analyze the structural heterogeneity of soy‐based polyols and its effect on the properties of polyols and polyurethanes. RESULTS: A series of polyols with a range of hydroxyl numbers were prepared by hydroformylation and partial esterification of hydroxyls with formic acid. Polyols were reacted with diphenylmethane diisocyanate to obtain polyurethanes of different crosslinking density. Gelation was simulated using the Monte Carlo method with a calculated distribution of functionalities for each polyol. CONCLUSIONS: Most polyols are powerful crosslinkers since weight average functionality varied from 5 to 2.5 resulting in gel points from 53 to 83% conversion. Heterogeneity of polyols had a negative effect on mechanical properties of rubbery polyurethanes and this should be taken in account when designing polyols for flexible applications. This effect was not pronounced in glassy polyurethanes. Copyright © 2007 Society of Chemical Industry     

Influence of cycloaliphatic compounds on the properties of polyurethane coatings

A series of polyester polyol resin was synthesized by using 1,4-cyclohexanedimethanol (1,4-CHDM) and three different diacids: 1,3-cyclohexanedicarboxylic acid (1,3-CHDA), isophthalic acid (IPA) and adipic acid (AA). The solubility and viscosity of the polyester polyols were determined by using methyl ethyl ketone (MEK). All the polyester polyols were crosslinked with hexamethylene diisocyanate (HDI) isocyanurate to form polyurethane coating films. These films were evaluated for their mechanical and chemical resistance properties. Studies on the film characteristics revealed that the polyurethane films based on cycloaliphatic diacid generally showed comparatively better performance properties than the polyurethane film based on aromatic and linear aliphatic diacids in general.     

Highly functional biobased polyols and their use in melamine–formaldehyde coatings

Highly functional sucrose soyate polyol (SSP) resins were synthesized by ring-opening epoxidized sucrose soyate with methanol or ethanol and were subsequently crosslinked with a melamine–formaldehyde (MF) resin in the presence of an acid catalyst or blocked acid catalyst. The biobased polyols were characterized by Fourier transform infrared spectroscopy, gel permeation chromatography, proton nuclear magnetic resonance spectroscopy, Brookfield viscosity, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The thermal properties of the biobased MF coatings were studied using differential scanning calorimetry and dynamic mechanical analysis. As controls, a soybean oil polyol (SBOP) with lower functionality and a commercial polyester polyol were studied for comparison. Overall, MF coatings formulated with SSPs showed superior properties to coatings formulated with SBOP and comparable properties to the commercial polyester which was attributed to the high hydroxyl functionality.     

Green polyurethane from dimer acid based polyether polyols: Synthesis and characterization

In this study, dimer acid (DA) obtained from waste soybean oil was used together with propylene oxide (PO) to obtain novel polyether polyols [prepolymers for polyurethanes (PUs)] through ring‐opening polymerization reaction. The average molecular weight of polyols was estimated by gel permeation chromatography and titration method. The substantial reaction between DA and PO was evident from FTIR and nuclear magnetic resonance spectroscopy. Subsequently, the polyols were reacted with chain extender [ethylene glycol, (EG)] and 4, 4 ‐ Diphenylmethane diisocyanate (MDI) to prepare green PUs. The effect of molar ratio variation of EG and MDI with a fixed amount of polyols was estimated by measuring hydrophobicity and mechanical strength of PUs. The molar ratio such as 1 : 4 : 5.7 of polyol : EG : MDI was found to exhibit maximum hydrophobicity and improved mechanical strength that were comparable with typical PU sample prepared from commercially available polyol, such as polypropylene glycol. FTIR spectroscopic analysis confirmed the chemical changes and possible crosslinking in PUs. Thermalgravimetric analysis and differential scanning calorimetry analysis also showed substantial thermal stability of the green PUs. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41410.     

The kinetics of polyesterifications. IV. Polyol from BHET and adipic acid and its urethanes

New polyol containing aromatic rings was prepared from BHET, or BHET/ethylene glycol mixtures and adipic acid. In this new system, the kinetics of polyesterification were investigated and were shown to follow the kinetic equations proposed by Lin and his co-workers which were obtained by modifying Flory's theory. Polyurethane elastomers were prepared by reacting these polyols and toluene diisocyanate (TDI) in DMF solution with NaCN as a crosslinking catalyst at room temperature. Their physical properties such as density, gel fraction, swelling ratio, mechanical properties, etc., were measured. High values of elastic modulus are due to the rigid segment of BHET. By varying the molar ratio of diisocyanate and polyester, polyurethanes with different crosslinking densities can be obtained. The relationship between physical properties and crosslinking density was shown to follow the general theory of rubber elasticity.     

Flame-retarding materials. II. Synthesis and flame-retarding properties of phosphorus-on-pendent and phosphorus-on-skeleton polyols and the corresponding polyurethanes

A phosphorus-on-skeleton compound was synthesized by reacting phenyl dichlorophosphate (PDCP) with 2-hydroxyethyl methacrylate (HEMA). This monomer was then copolymerized with other acrylic monomers to form a hydroxy-containing copolymer, which was then used as the polyol in the synthesis of a polyurethane. Phosphorus-on-pendent copolymers and phosphorus-free copolymers and their corresponding polyurethanes were also prepared for comparison with the phosphorus-on-skeleton material in terms of their flame-retardant properties. The flame retardancy and degradation mechanism of these copolymers and polyurethanes were analyzed with thermogravimetric analysis (TGA) and infrared spectroscopy. Although those phosphorus-on-skeleton copolymer polyols have less flame-retarding ability than that of the phosphorus-on-pendent copolymer polyol because of less phosphorus content, it was evident that the phosphorus-on-skeleton polyurethanes were more effective flame retardants than the phosphorus-on-pendent polyurethanes. This was attributed to the fact that the crosslinking arising from the phosphorus-on-skeleton copolymer polyols has a tremendous effect on the flame-retarding ability of the corresponding polyurethanes. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 343–357, 2001     

水性聚氨酯压敏胶的合成及其性能表征

以异佛尔酮二异氰酸酯(IPDI)、聚醚多元醇(N220、N210)、二羟甲基丙酸(DMPA)和三羟甲基丙烷(TMP)为主要原料制得了环保交联型水性聚氨酯(WPU)压敏胶,讨论了n(-NCO)/n(-OH)比值、交联剂用量以及聚醚相对分子质量大小对该压敏胶性能的影响。研究结果表明,由N220合成的WPU压敏胶的初粘力优于由N210合成的WPU压敏胶;随着n(-NCO)/n(聚醚中-OH)比值的减小,压敏胶的初粘力提高,持粘力呈先降后增再降的趋势;适度的交联可以提高压敏胶的粘接强度;当n(-NCO)∶n(聚醚中-OH)为2.5∶1、n(TMP中-OH)∶n(聚醚中-OH)为1∶3.0时,压敏胶的综合性能优异,初粘力达到13号钢球,持粘力达到23.1h,180°剥离强度达到20.14N/(20mm)。     

聚合物多元醇在聚氨酯微孔弹性体中的应用研究

对聚合物多元醇在聚氨酯微孔弹性体中的应用进行了研究。考察了聚合物聚醚多元醇及聚合物聚酯多元醇对聚氨酯微孔弹性体力学性能的影响。实验结果表明,该类聚合物多元醇的引入可使聚氨酯微孔弹性体制品的力学性能得到较大改善,因此该类聚合物多元醇在聚氨酯领域必将具有广阔的应用前景。     

Comparison of Adipic Versus Renewable Azelaic Acid Polyester Polyols as Building Blocks in Soft Thermoplastic Polyurethanes

In this study, novel polyester diols of 2000 molecular weight (MW) were synthesized by reacting azelaic acid (AZ) with 1,3‐propanediol (1,3‐PDO) and diethylene glycol (DEG) in the esterification reaction catalyzed with a small amount of butyltintris(2‐ethylhexanoate). As a reference, polyester polyols of 2000 MW were synthesized from adipic acid (AA) with 1,3‐PDO and DEG. The properties of polyester polyols were evaluated. The polyester polyol based on AZ and 1,3‐PDO is 100 % renewable polyol; 1,3‐PDO used in the syntheses is renewable product produced by fermentation process of sugar. Both 1,3‐PDO‐polyester polyols exhibited crystalline transition above room temperature, while DEG‐polyester polyols were liquid at room temperature. The polyester polyols were chain‐extended with 4,4′‐diphenylmethane diisocyanate (Mondur M) and 1,4‐butanediol (BDO) to form thermoplastic polyurethanes (TPU). TPU were evaluated for mechanical and water resistance properties, and their morphology were studied via differential scanning calorimetry (DSC), Fourier transform infrared (FTIR), and atomic force microscope (AFM). TPU based on azelate and adipate polyols were relatively soft elastomeric materials with high melting temperatures. AFM analyses of TPU indicated better phase separation in 1,3‐PDO polyester polyols with the highest phase separation observed in TPU based on 1,3‐PDO/azelaic acid polyols. Water resistance of TPU based on azelate polyols was improved as compared to TPU based on adipate polyols.     

Nanofilled polyols for viscoelastic polyurethane foams

The use of polyether polyols is common in polyurethane industry, particularly in soft PU applications. In particular, viscoelastic foams, characterized by slow recovery after compression, are obtained using poly(ethylene oxide) (PEO) polyols. Nanofilled polyols can be used for the production of viscoelastic foams with improved fire resistance properties. The high polarity of polyether polyols is responsible of a poor affinity with the organic modifiers used in commercial organically modified montmorillonite (omMMT). In this work, organically modified montmorillonites were prepared, having an improved affinity with the polyether polyols used for the production of soft PU foams. The montmorillonite was modified by using polyetheramines with different ethyleneoxide/propyleneoxide amounts. A strongly intercalated/exfoliated structure was obtained after mixing the polyol with the omMMT. The viscosity increased by three orders of magnitude and the diffraction angles of the MMT measured by x‐ray analysis decreased to values lower than 1.5°. The intercalated structure was preserved after the curing stage, when the isocyanate was added to the polyol/omMMT. The resulting polyurethane had an irregular open cell structure, and was characterized by a mechanical properties comparable to those of unfilled polyurethane. Copyright © 2009 Society of Chemical Industry     

Effect of isocyanate to hydroxyl index on the properties of clear polyurethane films

Clear polyurethane films were made from aqueous polyurethane pre-polymer dispersions and water-dispersible aliphatic isocyanate pre-polymer, varying the amount of isocyanate used to cure the films. Film series were made from one of two polyol dispersions; the control XP-7110 having a higher molecular weight and containing 10 wt.% n-methylpyrrolidone (nmp) was compared to a zero-volatile organic compound (VOC) lower molecular weight alternate polyol XP-2591. Increasing the relative number of isocyanate groups to hydroxyl groups in these films provided an increase in glass transition temperature (T_g), tensile strength, elastic modulus and improved barrier properties to dimethyl methylphosphonate (DMMP) for both polyols in this study. At all indices in this study XP-7110 films achieved slightly higher T_g and slightly better resistance to permeation by DMMP than the XP-2591 films. Water resistance of the films was not improved at higher indices nor was there any difference between the polyols. Yet, the experimental results suggest that it is possible to produce polyurethane binders with acceptable film properties while reducing the VOC content of the formulation by using t-butyl acetate as the isocyanate reducing solvent. The zero-VOC polyol achieved better tensile properties with higher indexing than the current polyol containing 10 wt.% VOC. While the zero-VOC polyol did not perform as well as the baseline polyol in some tests, the differences in performance were small and thus there may be an opportunity to use the zero-VOC polyol as a partial or even a complete replacement of the current material.     

Physical properties of water‐blown rigid polyurethane foams from vegetable oil‐based polyols

Fifty vegetable oil‐based polyols were characterized in terms of their hydroxyl number and their potential of replacing up to 50% of the petroleum‐based polyol in waterborne rigid polyurethane foam applications was evaluated. Polyurethane foams were prepared by reacting isocyanates with polyols containing 50% of vegetable oil‐based polyols and 50% of petroleum‐based polyol and their thermal conductivity, density, and compressive strength were determined. The vegetable oil‐based polyols included epoxidized soybean oil reacted with acetol, commercial soybean oil polyols (soyoils), polyols derived from epoxidized soybean oil and diglycerides, etc. Most of the foams made with polyols containing 50% of vegetable oil‐based polyols were inferior to foams made from 100% petroleum‐based polyol. However, foams made with polyols containing 50% hydroxy soybean oil, epoxidized soybean oil reacted with acetol, and oxidized epoxidized diglyceride of soybean oil not only had superior thermal conductivity, but also better density and compressive strength properties than had foams made from 100% petroleum polyol. Although the epoxidized soybean oil did not have any hydroxyl functional group to react with isocyanate, when used in 50 : 50 blend with the petroleum‐based polyol the resulting polyurethane foams had density versus compressive properties similar to polyurethane foams made from 100% petroleum‐based polyol. The density and compressive strength of foams were affected by the hydroxyl number of polyols, but the thermal conductivity of foams was not. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Combinatorial approach to study the effect of acrylic polyol composition on the properties of crosslinked siloxane-polyurethane fouling-release coatings

The effect of acrylic polyol composition on the properties of crosslinked siloxane-polyurethane coatings was explored. An acrylic polyol library was synthesized using batch solution polymerization and characterized using high-throughput gel permeation chromatography (Rapid-GPC) and differential scanning calorimetry (DSC). Siloxane-polyurethane coatings were prepared from 3-aminopropyl-terminated poly(dimethylsiloxane) (PDMS), the acrylic polyols and a polyisocyanate crosslinker. The siloxane-acrylic-polyurethane coatings were tested for mechanical and physical properties. The siloxane-polyurethane coatings had a systematic variation in glass transition temperature and had water contact angles ranging from 95° to 100°. Many of the coatings also showed a low-force of release in the pseudo-barnacle pull-off adhesion test. Performance testing of the fouling-release properties of the siloxane-polyurethane coatings on array panels with algae, namely the diatom Navicula and sporelings (young plants) of the green seaweed Ulva was also conducted. Presented at the 2006 FutureCoat! conference, sponsored by the Federation of Societies for Coatings Technology, in New Orleans, LA, on November 1–3, 2006.     

Physical properties of new polyurethanes foams from benzene polyols synthesized from erucic acid

High density triol‐based polyurethane (PU) foams were developed from aromatic triol isomers prepared from erucic acid. The triol monomers were crosslinked with 4,4′‐diphenylmethane diisocyanate (MDI) into PU foams. The foam's properties were studied by Fourier transform infrared (FTIR) spectroscopy, X‐ray diffraction (XRD), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The foams were analyzed for closed cell content and compression strength. The effect of the benzene ring in the polyol structure on the physical properties of these new PU foams was compared with high density foams made from aliphatic polyols originating from canola oil. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010