Polyether Diol Research Articles

Amine-quinone polyurethanes: Preparation of polyurethane segmented block copolymers containing 2,5-bis(N-2-hydroxyethyl-N-methylamino)-1,4-benzoquinone, toluene diisocyanate, and an oligomeric polyether diol

The amine-quinone diol monomer 2,5-bis(N-2-hydroxyethyl-N-methylamino)-1,4-benzoquinone (AQM-1) was prepared by the condensation of 2-(N-methylamino)ethanol with hydroquinone in the presence of oxygen and copper(II) chloride. This crystalline monomer was used to prepare a series of amine-quinone polyurethanes by condensation polymerization, either in the melt or in DMF solution, with toluene diisocyante and an oligomeric diol either poly(1,2-butylene glycol) or polytetrahydrofuran. The amine-quinone functional group was incorporated into the polymer mainchain, giving red-brown polyurethanes that had molecular weights in the range of 20,000–80,000 and were soluble in THF, MEK, DMF, and DMSO. The thermal properties were consistent with a two-phase morphology with an amorphous soft segment, containing the oligomeric diol, and a microcrystalline hard segment, containing AQM-1. These polymers had a high affinity for the surface of commercial iron particles used in state of the art magnetic tape and prevented the corrosion of the particles. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 2339–2345, 1999

Degradation process of an industrial thermoplastic elastomer polyurethane-coated fabric in artificial weathering conditions

The aging of an industrial thermoplastic elastomer polyurethane (TPU)-coated fabric, based on a polyether diol and an aromatic diisocyanate, is studied in artificial weathering tests. It is noticed that the degradation of this TPU-coated fabric leads to a weight loss, to the formation of a reticulated layer in sample surface, and to a change of surface relief. The degradation layer and the surface relief have been observed by optical microscopy. The weight loss has been followed with aging time. The main degradation products causing weight loss are volatile. Therefore, they have been analyzed by gas chromatography-mass spectroscopy. The weight loss degradation takes place in the exposed part of the reticulated layer by volatile products emission, which implies the urethane and the polyether bonds. Water is involved in degradation process: without external water supply, weight loss is limited; with a permanent contact of vapor or liquid water, the weight loss rate is constant and depends on aging conditions.

Elasticity behavior of swollen polyurethane networks

A series of polyurethane networks were prepared by reacting MDI (4,4′-diphenylmethane diisocyanate) with various mixtures of poly(oxyethylene) end-capped poly(oxypropylene) triol and diol. The uniaxial compressive properties of the polyurethane networks both in equilibrium swelling in toluene and in a dried state were measured at 27 °C. The compressive stress-strain data were analyzed according to equations based on the Gaussian theory of elasticity. Deviations from the Gaussian behavior were observed; however, as the polyether diol content increased, deviations from the Gaussian behavior decreased. The interaction parameters between the polyurethane networks and toluene at an equilibrium state were analyzed by the Flory-Huggins equation. As the polyether diol content increased, the interaction parameter, χ, increased due to the increasing content of the poly(oxyethylene) unit and urethane group concentration. With increasing polyether diol content, polyurethane networks approached phantom behavior more closely.

Polyurethane-maleamides for cardiovascular applications: synthesis and properties.

Several polyurethane-maleamides (PUMAs) containing polyether or polycarbonate soft segments, and aromatic or aliphatic hard segments were synthesized by solution or bulk polymerization, using maleic acid (MA) or a mixture of MA and butanediol as chain extenders. Using this process, activated double bonds are introduced into the polymer chains and the base polyurethanes may undergo further modification via specific grafting, thus improving their tissue compatibility. PUMAs chemicophysical properties were evaluated by gel permeation chromatography (GPC), intrinsic viscosity analyses, differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR) and tensile mechanical tests. Polycarbonate diol (PCU)-based PUMAs showed higher molecular weights than polyether diol (PEU)-based ones. The use of butanediol in mixture with maleic acid led to an increase of molecular weights. FT-IR confirmed the presence of the bands related to the amide groups and to the conjugated double bond, yet more evident for the polymer obtained in solution. The higher crystallinity shown by this polymer was also indicative of a better phase separation. All the PCU-PUMAs exhibited similar tensile properties with a higher stiffness than PEU-PUMAs. Among the PEU-PUMAs, the highest tensile properties were shown by the polymer obtained in solution, and by the one derived from a mixture of maleic acid and butanediol.

Synthesis of a molecular mill designed from a calix[4]- bis-crown

The synthesis of molecular mill 4 has been achieved by condensing the dibromomethyl derivative of a calix[4]- bis-crown 1 with naphtho polyether diol 2 in high dilution conditions.

Synthesis and Hemocompatibility Evaluation of Novel Segmented Polyurethanes with Phosphatidylcholine Polar Headgroups

A new diol with a phosphatidylcholine polar headgroup, [bis(2-hydroxymethyl)]propane-2-(trimethylammonio)ethyl phosphate (BTEP), was synthesized and characterized. The BTEP, together with 1,4-butanediol (BD) as a chain extender, was used to synthesize segmented polyurethanes (SPUs) based on diphenylmethane diisocyanate (MDI) and various types of soft segments such as polycarbonate, polyether, polyester, and hydrocarbon diols. The bulk characteristics of the resulting SPUs were investigated by infrared (IR) spectroscopy, viscosity, and gel-permeation chromatography (GPC) measurements. Good mechanical properties of the typical SPU containing poly(butadiene) glycol (PBD) were indicated by dynamic viscoelasticity and tensile measurements. The phosphatidylcholine polar groups were oriented on the surface of these materials as revealed by attenuated total reflectance−Fourier transform infrared spectroscopy (ATR−FTIR), electron spectroscopy for chemical analysis (ESCA), and contact angle measurements. The hemoco...

Correlation of linear viscoelastic behavior and molecular weight evolution in the bulk urethane polymerization

Bulk polymerization of urethane made from diphenylmethane 4, 4′ diisocyanate (MDI) and polyether macro diol was performed from size exclusion chromatography and viscoelastic studies. Coupling the viscoelastic characterization and the kinetic law showed that the viscoelastic behavior of the urethane system is only dependent of the degree of polymerization. The rheological study proved that low physical interactions can be found between the polyurethane chains. Furthermore, the critical molecular weight corresponding to a rheological maximum effect of these interactions was observed close to the value Mc = 2Me, characterizing the onset of the topological entanglement coupling. A qualitative explanation of this singular behavior was attempted from a hydrogen bonding point of view. On the other hand, the linear viscoelastic properties of polyurethane samples of different molecular weights were studied. The main viscoelastic parameters, ηo, and were determined. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 2395–2406, 1997

Phase separation in segmented poly(urethane urea) copolymers during reaction injection molding (RIM) polymerization

In situ experiments were performed with a portable RIM (reaction injection molding) minimachine interfaced to an FTIR spectrophotometer to follow the reaction chemistry and monitor phase separation of copoly(urethane urea)s during RIM polymerization. The PUU copolymers were based on ethylene oxide-capped poly(propylene oxide) polyether diol, 3,5-diethyltoluenediamine (DETDA), and uretonimine liquefied 4,4′-diphenylmethane diisocyanate. The effect of catalyst concentration on the degree of phase separation in the as-molded RIM PUU copolymers was investigated by using differential scanning calorimetery and scanning electron microscopy as supplementary methods. The results suggested that an increase of degree of phase separation and a decrease of the size of hard-segment-rich domains take place with a rise of catalyst concentration. The morphological feature was a consequence in combination with the increase in relative rate of urethane formation and the ordering of hydrogen bonding through urea groups. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35: 865–873, 1997.

Phase separation in segmented poly(urethane urea) copolymers during reaction injection molding (RIM) polymerization

In situ experiments were performed with a portable RIM (reaction injection molding) minimachine interfaced to an FTIR spectrophotometer to follow the reaction chemistry and monitor phase separation of copoly(urethane urea)s during RIM polymerization. The PUU copolymers were based on ethylene oxide-capped poly(propylene oxide) polyether diol, 3,5-diethyltoluenediamine (DETDA), and uretonimine liquefied 4,4′-diphenylmethane diisocyanate. The effect of catalyst concentration on the degree of phase separation in the as-molded RIM PUU copolymers was investigated by using differential scanning calorimetery and scanning electron microscopy as supplementary methods. The results suggested that an increase of degree of phase separation and a decrease of the size of hard-segment-rich domains take place with a rise of catalyst concentration. The morphological feature was a consequence in combination with the increase in relative rate of urethane formation and the ordering of hydrogen bonding through urea groups. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35: 865–873, 1997.

Phase separation in segmented polyurethanes derived from mixtures of polyether polyols with different functionality

A series of segmented polyurethanes containing 60 wt° of hard segments (HS) was prepared from MDI (4,4′-diphenylmethane diisocyanate) ethylene glycol and mixtures of a polyoxyethylene end-capped polyoxypropylene triol and a polyoxyethylene end-capped polyoxypropylene diol. The effects of the content of polyether diol in polyether polyols on phase separation and properties was investigated by dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC) and investigation of tensile properties. The DSC and DMA results indicate that the polyurethane derived from only polyether triol exhibits obvious phase separation and that the HS is immiscible with the SS, but that the HS is compatible with the HS for the polyurethane derived from polyether diol. As the content of polyether diol increases, the compatibility between HS and SS increases. As the content of polyether diol increases, the tensile strength. elongation. toughness and tear resistance of the polyurethanes increases. but their moduli decrease. The modulus-temperature dependence in the temperature region of −30 to 65 °C increases as the polyether diol content increases.

Crystallinity and hydrogen bonding of hard segments in segmented poly(urethane urea) copolymers

Polyurea hard segment model compounds and a series of segmented poly(urethane urea) (SPUU) copolymers, with hard segment content ranging from 18.8–91.0%, were synthesized based on 4,4′-diphenylmethane diisocyanate (MDI), 3,5-diethyltoluenediamine (DETDA), and ethylene-oxide-capped poly(propylene oxide) polyether diol (PPO). By analysis of model compounds, crystallization of DETDA-MDI hard segments was confirmed and relationships between urea hydrogen bonding with morphological changes were suggested. The crystallization, however, was not complete in the copolymers even when the hard segment content was high. New spectral evidence for phase inversion is presented. Fourier transform infra-red analysis suggested that the equilibrium of urea hydrogen bonding between crystalline region and amorphous regions was affected mainly by morphological changes (phase inversion) and was almost independent of chemical composition of the SPUU copolymers under certain morphological conditions both before and after phase inversion.

Effect of urea groups on reaction kinetics of polyurethane formation

Urea-containing polyurethane reaction systems, based on ethylene oxide-capped poly(propylene oxide) polyether diol, 1,4-butyldiol, uretonimine liquefied 4,4'-diphenylmethane diisocyanate, and a biurea compound, were used to investigate the effect of urea groups on polyurethane bulk polymerization by using Fourier transform infrared spectroscopy. The biurea compound was a liquid biurea-capped poly(propylene oxide) polyether, which can mix well with the polyurethane systems. Catalysis of urea groups was observed clearly regardless of whether organotin catalyst was used. A catalytic mechanism was presented in this paper.

Synthesis and characterization of segmented polyurethanes based on amphiphilic polyether diols

Segmented polyurethanes (SPUs) based on polyethylene glycol (PEG), polypropylene glycol (PPG) and a series of Pluronics with different ethylene oxide/propylene oxide ratios (EO/PO) and molecular weights were prepared. Different diisocyanates were used for making SPUs: 4,4-diphenylmethane diisocyanate (MDI), 4,4-dicyclohexylmethane diisocyanate (MDCI), hexamethylene diisocyanate (HMDI) and isophorone diisocyanate (IPDI). 1,4-Butane diol (BD) and ethylene diamine (ED) were used as chain extenders. The polymers obtained were characterized by infrared spectroscopy (IR), nuclear magnetic resonance (NMR) and differential scanning calorimetry (DSC). The microphase morphology (phase separation and phase mixing) is discussed in more detail.

Toughening of epoxy resin by reacting with functional terminated‐polyurethanes

AbstractHydroxyl‐, amine‐, and anhydride‐terminated polyurethane (PU) prepolymer which were synthesized from polyether (PTMG) diol, 4,4′‐diphenylmethane diisocyanate (MDI), and a coupling agent bisphenol‐A, 4,4′‐diaminodiphenyl sulfone (DDS), or benzophenonetetracarboxylic dianhydride (BTDA) were used to modify the toughness of bisphenol‐A diglycidyl ether epoxy resin (DGEBA) cured with 4,4′‐diaminodiphenyl sulfone. From the experimental results, it was shown that the modified resin displayed a significant improvement in fracture energy (GIC) and also in its interfacial shear strength with polyaramid fiber. It was more enhanced with increase of the PU modifier wt % content. The hydroxyl‐terminated PU was found to be the most effective among those three prepolymers. In addition, the toughening mechanism was discussed based on the morphological and the dynamic mechanical behavior of the modified epoxy resin. Fractography of the specimen observed by transmission (TEM) and scanning electron microscopy (SEM) revealed that the modified resin had a two‐phase structure. The existence of an unclean fiber surface after its fiber pullout test suggested that a ductile fracture might have occurred. © 1995 John Wiley & Sons, Inc.

Polyethers containing stable ionic end‐groups

AbstractPolyethers of low and medium molecular weight containing at both ends stable ionic groups (phosphonium ions) were obtained by living cationic polymerization of tetrahydrofuran initiated by difunctional initiator, trifluoromethanesulfonic anhydride, followed by termination with triphenylphosphine. It was shown, that products contain significant quantities of low molecular weight diphosphonium salt; a plausible explanation is presented. Alternative approach to the synthesis of diionically terminated polyethers was based on the conversion of hydroxyl end‐groups of polyether diols, which can be obtained by cationic Activated Monomer (AM) polymerization of e.g. oxiranes, into phosphonium ion end‐groups. Using this approach, poly(ethylene oxide)'s with Mn ranging from 300 to 3400, terminated at both ends with stable ionic groups, were prepared and characterized. Measurements of NMR relaxation times and viscosity measurements provide the evidence for the aggregation of ionic end‐groups. The potential applications of inter‐ and intramolecular aggregation are discussed. It is shown, that intramolecular aggregation of ionic terminal groups in low molecular weight poly(ethylene oxide) leads to cyclic structures resembling crown ethers and showing comparable efficiency for complexing cations.

Radiation-cured polyurethane methacrylate pressure-sensitive adhesives

New oligomeric polyurethanes have been prepared from polyether diols, chain extender and 4,4′-dicyclohexylmethane diisocyanate or 4,4′-diphenylmethane diisocyanate, which are terminated with a mixture of 2-hydroxyethyl methacrylate (2-HEMA) and non-functional terminators such as n-propanol or technical hydroabietyl alcohol. The oligomers may be cured by electron beam or u.v. radiation to give pressure-sensitive adhesives.

Protection of Fe pigments with amine-quinone polymers

High magnetization iron pigments, protected by amine-quinone polymers are described. The amine-quinone polyurethanes were prepared by melt polymerization of 2,5-bis(N-2-hydroxyethyl-N-methylamino)-1,4-benzoquinone, AQM-1, tolylene diisocyanate, and an oligomeric polyether diol; either poly(1,2-butylene glycol) or poly(1,4-butylene glycol). Depending on the choice of polyether and the relative amount of AQM-1, the polyurethanes were elastomeric or thermoplastic; the thermal and mechanical properties being systematically controlled by the polymer structure. Hydrogen reduction of acicular iron oxide pigments gave pyrophoric Fe pigments with an initial /spl sigma//sub s//spl ap/195 emu/g. Treatment with a THF solution of the amine-quinone polymer AQPU-8, under an inert atmosphere, gave stabilized Fe pigments with /spl sigma//sub s//spl ap/160 to 180 emu/g; a value significantly higher than 140 emu/g for the best ceramic coated pigments. The treated pigments were exposed to the ambient laboratory atmosphere for more than 3000 hours with no loss in /spl sigma//sub s/. This demonstration that quinone polymers can replace the ceramic coatings used to protect iron pigments provides a means of significantly enhancing the performance of metal particle tape. >

Thermoplastic Polyurethane Elastomers Made from High Molecular Weight POLY-L® Polyols

High molecular weight polyether polyols formed by the poly merization of epoxides, especially propylene oxide, using conventional KOH catalysis contain high levels of unsaturation. This unsaturation is in the form of allyl and isopropenyl end groups and results in a loss of functionality. A diol that ideally has a functionality of 2.0 can be as low as 1.70 for a conventional 4000 molecular weight polyol. As the molecular weight increases the func tionality decreases. Since the unsaturation is a function of molecular weight, a limiting molecular weight will be reached where further propylene oxide fails to add to the chain and to increase molecular weight. High molecular weight polyether diols containing low unsaturation were pre pared using double metal cyanide catalysts. With these catalysts ultra high molecular weight polyols can be made without a concomitant increase in the rate of formation of unsaturated end groups. A 4000 molecular weight diol was made that had unsaturation levels five times lower than a comparable polyol prepared by conventional KOH catalysis. Additionally, 5500 and 6600 molec ular weight diols containing very low unsaturation levels were also made. All of the polyols were capped with ethylene oxide to give high levels of primary hydroxyl groups. These polyols were evaluated in thermoplastic polyurethane elastomer formulations. The thermoplastic polyurethane elastomers were based on MDI and chain ex tended with butanediol. Those prepared from polyols with low unsaturation levels had significantly higher physical properties than thermoplastic polyurethane elastomers prepared with conventionally made polyols. Soft ther moplastic polyurethane elastomers were made from high molecular weight polyols containing low unsaturation levels. These soft thermoplastic polyure thane elastomers are softer than any currently commercially available. They exhibited good tensile strength, excellent elongation and high resilience prop erties.

Effects on properties of varying the cis/trans isomer distribution in polyurethane elastomers made with 1,4‐cyclohexane diisocyanate

AbstractPolyurethane elastomers have been made using 1,4‐cyclohexane diisocyanate (CHDI), 1,4‐butanediol (BDO) and a 2000 Mn polyether diol soft segment. The cis/trans isomer distribution of the CHDI was varied between 23% and 100% trans. This variation in isomer distribution had significant effects on the polyurethane's thermal and physical properties.Decreasidng the trans CHDI content gives polyurethanes with lower hardness, lower thermal stability, higher Coefficient of Linear Thermal Expension (C.L.T.E.) values and decreased modulus values. Morphology studies showed good phase separation between the hard and soft segment blocks as well as a block copolymer morphology between the cis and trans CHDI/BDO blocks in the hard segment. The polyurethanes made were compared to polyurethanes made with MDI and H12MDI, the leading aromatic and aliphatic diisocyanates respectively.

A convenient synthesis of substituted polyether diols

Alkyl-substituted polyether diols (or polythioether diols), which are potential precursors to substituted crown ethers, are produced in high yield by the selective reductive cleavage of C−O bonds in bis(cyclic acetals) [or bis(cyclic hemithioacetals)] by borane or monochloroborane