Synthesis and characterization of a series of poly(alkylene carbonate) macrodiols and the effect of their structure on the properties of polyurethanes

A series of polycarbonate and copolycarbonate macrodiols was prepared by using an ester interchange reaction with ethylene carbonate and diols such as 1,6-hexanediol, 1,10-decanediol, 2,2-diethyl-1,3-propanediol, 1,4-cyclohexanedimethanol, and 1,3-bis(4-hydroxybutyl)-1,1,3,3-tetramethyldisiloxane. The diols were chosen to prepare a series of macrodiols with different structural features including linear, branched, rigid, and flexible. The macrodiols were characterized by ¹H- and ¹³C-NMR spectroscopy and DSC. The commercial macrodiol based on 1,6-hexanediol exhibited a high level of crystallinity, while with the exception of 1,10-decanediol–based copolycarbonates all the others were completely amorphous. 1,10-Decanediol–based materials showed partial crystallinity under subambient conditions. A series of polyurethane elastomers with a constant hard segment percentage (40 wt %) was prepared using 4,4′-methylenediphenyl diisocyanate and 1,4-butanediol as the hard segment. Tensile test results and Shore hardness measurements demonstrated that polyurethanes based on polycarbonate macrodiols prepared from 1,3-bis(4-hydroxybutyl)-1,1,3,3-tetramethyldisiloxane had the lowest modulus and hardness of the series of polyurethanes. The remaining polyurethanes had high tensile strength with poor elasticity. The morphology of the polyurethanes, as determined by DSC analysis, varied from completely phase-mixed to well phase-separated structures. Polyurethanes based on macrodiols prepared from 1,3-bis(4-hydroxybutyl)-1,1,3,3-tetramethyldisiloxane showed good phase-separated morphology, with sharp hard segment melting endotherms and soft segment glass transitions close to that of the pure soft segment. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 1621–1633, 1998     

Cycloaliphatic polyester based high solids polyurethane coatings: I. The effect of difunctional alcohols

High-solids polyesters were synthesized with two cycloaliphatic diacids, 1,4- cyclohexanedicarboxylic acid (1,4-CHDA) and 1,3-cyclohexanedicarboxylic acid (1,3-CHDA); and with five diols, 1,4-cyclohexanedimethanol (CHDM), neopentyl glycol (NPG), hydroxypivalyl hydroxypivalate (HPHP), 2-butyl-2-ethyl-1, 3-propanediol (BEPD), and 1,6-hexanediol (HD). The viscosity of the polyesters was dependent on the structures of diols. The viscosity of polyesters is lower with the diol HD, intermediate with BEPD and HPHP, and higher with the diols CHDM and NPG. The polyesters were crosslinked with hexamethylene diisocyanate isocyanurate (HDI isocyanurate) affording polyurethane coatings. The mechanical properties, tensile properties, fracture toughness, and viscoelastic properties were investigated for the polyurethane films with five different diols. The cyclohexyl structure of the CHDM provides the polyurethane with rigidity which is manifested in high tensile modulus, hardness, and fracture toughness. In contrast, the linear diol, 1,6-hexanediol provides polyurethane with very high flexibility, but these coatings suffer with respect to low hardness and tensile modulus. Polymers and Coatings Department, Fargo, ND 58105. 3401 Grays Ferry Avenue, Philadelphia, PA 19146.     

Herstellung,Analyse und DC-Trennung von Fettsäurepartialestern mehrwertiger Alkohole

Preparation, Analysis and TLC-Separation of Partial Esters of Fatty Acids with Polybasic Alcohols Direct esterification of 99% capric acid, lauric acid, myristic acid, palmitic acid and stearic acid with ethyleneglycol, diethyleneglycol, thiodiethyleneglycol, triethyleneglycol, 1,2-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 2,5-hexanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol, 1,2,4-butanetriol, glycerol, 1,2,6-hexanetriol, trimethylolpropane and pentaerythritol in a molar ratio of 1 :1.25 yields 100 different partial esters of fatty acids. These partial esters are extensively freed from the polyhydric alcohols by washing with sodium sulfate solution and recrystallization in ethanol. Chemical constants and TLC-separation into classes and into polyhydric alcohols permit the evaluation of these compounds as emulsifiers, stabilizers and solubilization acids. All the partial esters of the fatty acids are mixtures, which can be separated by TLC according to the polyhydric alcohol moiety into monoester, diester, triester and tetraester; furthermore, the separation of positional isomers of monoesters and diesters is possible. Several observations made during the synthesis and analysis of partial esters of fatty acids are reported.     

丙烯醛水合加氢法制备1,3-丙二醇

简述了聚对苯二甲酸丙二酯 ( PTT)的特性、我国 PTT的发展状况 ,阐述了纤维级 1,3-丙二醇的研制、开发与生产对 PTT发展的重要性。着重介绍丙烯醛水合加氢法生产 1,3-丙二醇的工艺 ,并对丙烯醛水合反应、3-羟基丙醛加氢反应、4-氧代 -1,7-庚二醇水解反应、1,3-丙二醇提纯方法以及反应催化剂和反应条件进行了探讨     

UV curable,liquid diacrylate monomers based on (<Emphasis Type="Italic">cis,trans</Emphasis>)-1,3/1,4-cyclohexanedimethanol

Novel, liquid cycloaliphatic diacrylate monomers based on (cis,trans)-1,3/1,4-cyclohexanedimethanol have been synthesized for use in ultraviolet (UV)- and electron beam (EB)-cured coatings, inks, and adhesives. Diacrylate monomers prepared from this unique diol, and containing less than 15 wt% trans-1,4-cyclohexanedimethanol diacrylate, are liquid at room temperature and readily soluble in other acrylate monomers and oligomers (in contrast to diacrylates prepared from 1,4-cyclohexanedimethanol, which are solid). More importantly, UV-cured coatings based on (cis,trans)-1,3/1,4-cyclohexanedimethanol diacrylates (1,3/1,4-CHDMDA) show superior hardness, scratch resistance, and chemical resistance as compared to common diacrylate monomers used in the UV coating industry such as tripropylene glycol diacrylate, hexanediol diacrylate, dipropylene glycol diacrylate, and propoxylated neopentyl glycol diacrylate. Thus, this new monomer appears to be a promising material for enhancing the performance of radiation-cured coatings, inks, and adhesives applied to a variety of substrates, including plastic, paper, wood, metal, and glass. This paper will summarize the synthesis of liquid diacrylates from (cis,trans)-1,3/1,4-cyclohexanedimethanol, as well as the performance properties of the corresponding UV-cured coatings.     

HTPB-based Polyurethanes: a Correlation Study Between Morphology and Mechanical Behaviour

Hydroxyl-terminated polybutadiene and tolylene diisocyanate were used to prepare two series of polyurethanes by a two-step process. In the first series, the prepolymers were chain-extended with aliphatic compounds (1,3-propanediol, 1,4-butanediol and 1,6-hexanediol) and in the second, an aromatic chain extender (dihydroxy isopropyl-N-aniline) was used. Some results from mechanical testing showed different trends in comparison with previously reported results for similar systems. These findings were interpreted in terms of reactant reactivity, experimental procedures and morphology. Morphology was studied by means of swelling experiments, differential scanning calorimetry and scanning electron microscopy. © of SCI.     

Polyesters containing sulfur. I. Products of melt polycondensation of diphenylmethane-4,4′-di(methylthioacetic acid) with some diols

Several new polyesters containing sulfur in the main chain were obtained by melt polycondensation of diphenylmethane-4,4′-di(methylthioacetic acid) with ethanediol, 1,3-propane diol, 1,4-butanediol, 1,5-pentenediol, 1,6-hexanediol, 1,2-propanediol, and 2,2′-oxydiethanol. The structure of all polyesters was determined from elemental analysis and infrared (IR) spectra. Yield, reduced viscosity, molecular weight, and softening temperature for reaction products have been found. Initial decomposition and initial intensive decomposition temperature were defined from the curves of thermogravimetric analysis.     

Synthesis and characterization of hydroxy-terminated poly(alkylene oxides) by condensation polymerization of diols

Acid-catalysed condensation polymerization of 1,6-hexanediol, 1,8-octanediol and 1,10-decanediol was carried out in the 150–190°C temperature range in the presence of sulphuric acid or Nafion-H resin, and the polymerizations were monitored by size-exclusion chromatography. The products were identified as hydroxy-terminated poly(alkylene oxides) by ¹H and ¹³C NMR and IR spectroscopy. The polymers were obtained in 66–81% yield from both catalysts in the polymerizations of 1,8-octanediol and 1,10-decanediol. With 1,6-hexanediol the polymer yields were 30 and 42-56% in the presence of Nafion and sulphuric acid, respectively. These low yields were due to the formation of oxepane as confirmed by gas chromatographic analysis of volatile condensation products. Vapour pressure osmometry showed the number-average molecular weight of polymers to be in the range 700-2400, depending on the reaction time and temperature. The hydroxy functionality of the poly(alkylene oxides) was 2.0 as determined by vapour pressure osmometry and ¹H NMR spectroscopy.     

Effect of soft-segment CH2/O ratio on morphology and properties of a series of polyurethane elastomers

A series of six thermoplastic polyurethane elastomers were synthesized from a 4,4′-methylene diphenyl diisocyanate (MDI) and 1,4-butanediol (BDO) chain extender, with poly(ethyleneoxide) (PEO), poly(tetramethylene oxide) (PTMO), poly(hexamethylene oxide) (PHMO), poly(octamethylene oxide) (POMO), poly(decamethylene oxide) (PDMO), and poly(1,6-hexyl carbonate)diol (PCDO) macrodiol soft segments. The soft-segment molecular weights employed were similar (approximately 1000 g/mol) and each polyurethane contained 55% (w/w) of the soft-segment macrodiol. Differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA), wide-angle X-ray diffraction (WAXD), and Fourier transform infrared spectroscopy (FTIR) techniques were employed to characterize the morphology. Tensile and Shore hardness tests were also performed. Materials were tested in the as-molded, solvent-cast, and annealed states. It was found that the polyurethanes produced from macrodiols with the highest CH₂/O ratio displayed greater hard-domain crystallinity, a higher degree of phase separation, and the greatest hardness, stiffness, and opacity. POMO- and PDMO-based polymers displayed evidence of paracrystallinity in the soft domains. The PCDO-based material displayed a higher degree of phase mixing compared to the polyether-based materials. Annealing increased hard-domain crystallinity in all the polyether-based materials. The solvent-cast POMO- and PDMO-based materials had poor mechanical properties and were difficult to cast. The materials containing macrodiols with the lowest CH₂/O ratio were more readily solvent-cost and produced strong, useful films. Morphologies of the solvent-cast materials differed greatly from those of the molded materials. © 1996 John Wiley & Sons, Inc.     

Transparent polyester polyol-based polyurethane coatings: the effect of alcohols

A series of polyester polyols were synthesized using 1,6-hexanediol (HDO), 1,4-cyclohexanedimethanol (1,4-CHDM) and trimethylol propane (TMP), alone or in combination with 1,4-cyclohexanedicarboxylic acid and adipic acid. The polyester polyols were reacted with isocyanate trimers to form polyurethane (PU) coatings. Physical properties of the polyesters such as hydroxyl value, acid value, molecular weight, viscosity, and glass transition temperature (T _g) had been determined, and the IR spectroscopic analyses of polyesters/PU were reported. The properties (impact resistance, film flexibility, hardness, optical transmittance, chemical resistance, water absorption, thermostability, and phase separation) of the PU coatings so prepared were characterized. The viscosities of polyester polyols were dependent on the structure of the alcohols. Polyester polyol containing only linear aliphatic diol (HDO) was a transparent liquid at room temperature. The viscosity was increased by raising the molar ratio of 1,4-CHDM and/or TMP. All PU coatings had excellent flexibility, impact resistance, and hardness. The coatings derived from diol CHDM had the highest hardness, and the PU derived from diol HDO had the lowest hardness. The chemical resistance and water absorption improved with greater molar ratios of 1,4-CHDM or TMP. Results of differential scanning calorimetry and wide-angle X-ray diffraction indicated that there was no obvious crystallinity in the PU networks. Dynamic mechanical analysis (DMA) results revealed that both CHDM and TMP can increase the T _g of PU, and the crosslinking density improved with increased molar ratio of TMP. Atomic force microscope (AFM) and DMA analysis revealed that the PU coatings had no obvious microphase separation, which enabled them to have excellent properties, and the different composition in polyols did not have significant influence on transmittance in the visible region. Results of thermogravimetric measurements indicated that all the PU coatings had good thermal stability.     

The effect of diisocyanate isomer composition on properties and morphology of polyurethanes based on 4,4′-dicyclohexyl methane diisocyanate and mixed macrodiols (PDMS–PHMO)

Three series of polyurethanes were prepared having 42 wt % hard segments based on 4,4′-dicyclohexyl methane diisocyanate (H₁₂MDI) with trans,trans isomer contents in the 13 to 95 mol % range and 1,4-butanediol chain extender. The soft segments were based on macrodiols poly(hexamethylene oxide) (PHMO, MW 696), α,ω-bishydroxyethoxypropyl polydimethylsiloxane (PDMS, MW 940), and two mixed macrodiol compositions consisting of 80 and 20% (w/w) PDMS. H₁₂MDI with 35, 85, and 95% trans,trans isomer contents were obtained from commercial H₁₂MDI (13% trans, trans) by fractional crystallization, and all polyurethanes were prepared by a one-step bulk polymerization procedure. The polyurethanes based on the commercial diisocyanate-produced materials soluble in DMF with molecular weights in the 53,655–75,300 range and generally yielded clear and transparent materials. The polyurethanes based on H₁₂MDI with trans,trans contents of 35% or higher yielded materials insoluble in N,N-dimethylformamide (DMF) and were generally opaque. Mechanical properties, such as tensile strength and elongation at break, decreased with increasing trans,trans content, while the Young's modulus and Shore hardness increased. The polyurethanes based on mixed macrodiols yielded higher tensile properties than those of materials based on individual macrodiols. The best mechanical properties were observed for a polyurethane consisting of a soft segment based on PDMS–PHMO (80/20) and a hard segment based on commercial H₁₂MDI and BDO. Differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) were employed to characterize the polyurethane morphology. DSC results confirmed that the polyurethanes based on H₁₂MDI with high trans,trans isomer were very highly phase separated, exhibiting characteristic hard segment melting endotherms as high as 255°C. The other materials were generally phase mixed. FTIR spectroscopy results corroborated DSC results. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 573–582, 1999     

2-甲基-1,3-丙二醇的应用研究进展

综述了新型二元醇—2-甲基-1,3-丙二醇(MPO)的结构性能特点及MPO在聚酯树脂、醇酸树脂,增塑剂、胶黏剂、油墨、白电器外漆、个人护理用品等众多领域的应用进展和研发现状,尤其在高科技产品海岛纤维中的应用已引起注目。与传统二元醇如丙二醇、新戊二醇、1,4-丁二醇、1,6-己二醇等相比,MPO的产品具有非结晶性、强耐候性、与单体相容性好、污染小、抗拉伸、抗弯曲性强等主要性能优势,指出MPO是1种绿色环保、应用前景广阔的新型二元醇。     

End-grafting of oligoesters based on terephthalic acid and linear diols for high solids coatings

Oligomers derived from terephthalic acid and 1,6-hexanediol or 1,10-decanediol have been chemically modified through end-grafting with succinic anhydride or trimellitic anhydride followed by glycidyl neodecanoate. The grafted oligomers are paste-like semisolids or viscous liquids at room temperature. As the grafted oligomers are heated, their viscosity goes down to a minimum, then up to a maximum, and then down again. Combined DSC, crossed polarizing microscopy, and wide-angle x-ray diffraction indicate that the grafted oligomers form crystalline domains dispersed in amorphous phase. The grafted oligomers are soluble in common organic solvents, such as toluene, at lower concentrations (<14-51 wt %) and form stable dispersions at higher concentrations. High solid coatings formulated with mel-amine or isocyanate resins gave glossy films with excellent combined hardness and impact resistance. © 1996 John Wiley & Sons, Inc.     

Synthesis and characterization of transparent and high impact resistance polyurethane coatings based on polyester polyols and isocyanate trimers

A series of polyester polyols were synthesized by polycondensation reaction using adipic acid (AA), 1,4-cyclohexanedicarboxylic acid (1,4-CHDA), and 1,6-hexanediol (HDO), 1,4-cyclohexanedimethanol (1,4-CHDM) and trimethylol propane (TMP), in which the molar ratio of the reactants AA/1,4-CHDA was varied. These series of polyols were reacted with isophorone diisocyanate (IPDI) and hexamethylene diisocyanate (HDI), alone or in combination, to form polyurethane (PU) coatings.     

膨胀型阻燃剂在纤维及纺织品上的应用

介绍了螺环季戊四醇二磷酰氯(SPDPC)、环状1,3-丙二醇磷酰氯(CPPC)、环状2,2-二乙基-1,3-丙二醇磷酰氯(CDPPC)3种多元醇磷酰氯膨胀型阻燃剂(IFR)及其在纤维和纺织品上的应用;分析了3种纤维磷酸化的条件及结果。IFR能与聚酰胺纤维、羊毛及棉纤维反应而使之磷酸化,赋予纤维以耐久阻燃性。这类阻燃纤维耐沸水处理,具有膨胀型特征,与环境兼容,建议尽早开发,实现工业化生产。     

Characterization of Thermoplastic Polyurethanes Prepared Using Different Macroglycols

Three polyurethane elastomers (PU_s) were prepared using macroglycols of different nature (varepsilon-polycaprolactone, polyadipate of 1,6-hexanediol) and length of the hydrocarbon chain (polyadipate of 1,4-butanediol, polyadipate of 1,6-hexanediol). The PU_s were characterized using Gel Permeation Chromatography, Differential Scanning Calorimetry, Wide X-ray angle Diffraction, Dynamic Thermal Mechanical Analysis, stress-controlled rheometry and stress-strain experiments. The surface properties were evaluated from contact angle measurements. The PU_s were used as raw materials for solvent-based adhesives, whose adhesion properties were measured from T-peel strength of plasticized poly(vinyl chloride) (PVC)/polyurethane adhesive joints. The use of polyadipate of 1,6-hexanediol produced a polyurethane with high crystallinity (i.e. poor rheological and mechanical properties) and enhanced interactions between soft segments. Low adhesion was obtained in joints produced with this polyurethane and a cohesive failure of the adhesive was produced. The decrease in the polyadipate hydrocarbon chain length decreased the degree of crystallinity between polymer chains, therefore, no reduction in rheological and mechanical properties was obtained; a higher joint strength was also obtained. In this study the best performance was obtained with the polyurethane based on varepsilon-polycaprolactone, presumably because of its higher surface energy and reduced crystallinity. The properties of the polyurethanes prepared in this study were more affected by the characteristics of the macroglycol, and the crystallinity of the polyurethane had a more marked effect on the properties than the degree of phase separation.     

Physical properties of crosslinked polyurethane

Polyester based polyurethanes were synthesized from low molecular weight polyester (M_n 2000) and 4,4′-methylene bis(phenyl isocyanate) (MDI) with butanediol as a chain extender and glycerol as a crosslinker. The polyester was synthesized from adipic acid and glycol which was a mixture of 1,6-hexanediol and 1,2-propanediol. The effect of the crosslinker content on the degree of H-bond formation in the hard segments and the physical properties of polyurethanes were studied by differential scanning calorimetry (DSC), thermal mechanical analysis (TMA), Fourier transform infrared spectroscopy (FTIR) and mechanical testing. The experimental results revealed that incorporation of a triol crosslinker into the hard segments of polyurethane results in a decrease of hard segment H-bond formation. The mechanical data indicate that the mechanical properties of polyurethanes depend on the concentrations of physical and chemical crosslinks and that there is an optimum concentration of triol crosslinker for the tensile stress and elongation properties. © 1998 Society of Chemical Industry     

Poly(amide-ester)s from p-aminobenzoic acid

Poly(amide-ester)s containing p-aminobenzoic acid derived from three different diols (1,6-hexanediol, 1,4-butanediol, and trans-1,4-cyclohexanedimethanol) and two different acid chlorides (sebacoyl and adipoyl chloride) were synthesized by melt polymerization. The thermal and viscoelastic behaviour has been investigated and related to the chemical composition. All of the polymers synthesized showed an inherent viscosity ranging from 0·26 to 0·47dlg^-1. The poly(amide-ester)s prepared by melt polymerization showed a lower molecular weight and melting temperature than polymers prepared by solution polymerization. The lower melting points of the polymers prepared by melt polymerization were due either to the lower molecular weight or to breakage of intermolecular hydrogen bonding, which was attributed to amide–ester exchange reactions during polymerization. © 1998 SCI.     

Preparation and characterization of comb-shaped polyesters from 2,2-dioctadecyl-1,3-propanediol and phthalic acids

Summary New types of comb-shaped polyesters have been prepared by transesterification of 2,2-dioctadecyl-1,3-propanediol and the three isomeric diphenyl phthalates. Intrinsic viscosity and SEC analyses allowed determination of DPs (60–89) and molar masses; results compare well with absolute average weight molar masses (56,000–118,000) determined by low-angle laser light scattering. High-resolution ¹³C NMR reveals the characteristic aromatic and glycol polyester patterns; it resolves many side-chain methylene carbons, but shows no evidence of end-groups. All the polyesters are crystalline as shown by X-ray diffractometry and DSC, the crystallinity being exclusively due to the octadecyl side-group crystallization in the hexagonal form. The results indicate that the crystallinity decreases substantially when going from the ortho- to the terephthalate polyester.     

Low‐modulus siloxane–polyurethanes. Part II. Effect of chain extender structure on properties and morphology

A series of six polyurethanes were prepared to study the effect of silicon chain extender structure on properties and morphology of siloxane–polyurethanes. Polyurethanes were prepared by a two‐step bulk polymerization without a catalyst. The soft segment of the polyurethanes was based on an 80:20 (w/w) mixture of α,ω‐bis(6‐hydroxyethoxypropyl) polydimethylsiloxane (PDMS, MW 966) and poly(hexamethylene) oxide (MW 714). The hard segment was based on 4,4′‐methylenediphenyl diisocyanate (MDI) and a 60:40 molar mixture of 1,4‐butanediol (BDO) and a silicon chain extender. Silicon chain extenders (SCE) investigated were 1,3‐bis(4‐hydroxybutyl)1,1,3,3‐tetramethyldisiloxane (BHTD), 1,3‐bis(3‐hydroxypropyl)1,1,3,3‐tetramethyldisiloxane (BPTD), 1,4‐bis(3‐hydroxypropyl)1,1,3,3‐tetramethyldisilylethylene (HTDE), 1,3‐bis(6‐hydroxyethoxypropyl)1,1,3,3‐tetramethyldisiloxane (BETD). All polyurethanes were clear and transparent with number average molecular weights between 72,000 to 116,000. Incorporation of the silicon chain extender resulted in polyurethanes with low‐modulus and high elongation. This was achieved without significant compromise in ultimate tensile strength in all cases, except BETD. Differential scanning calorimetry (DSC) results showed that the silicon chain extenders did not significantly disrupt the hard segment crystallinity, but exhibited a unique morphological feature where SCE‐based hard segments formed separate domains, which may be the primary reason for achieving low modulus without significant compromise in strength. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1092–1100, 2003