Synthesis,characterization, and antibacterial activity of metal‐containing polyurethanes

Metal salts of mono(hydroxyethoxyethyl)phthalate [M(HEEP)₂] (M = Ca²⁺, Cd²⁺, and Pb²⁺) were synthesized by the reaction of diethylene glycol, phthalic anhydride, and metal acetates. A series of metal‐containing polyurethanes (PUs) were synthesized by the reaction of hexamethylene diisocyanate or tolylene 2,4‐diisocyanate with Ca²⁺, Cd²⁺, and Pb²⁺ salts of mono(hydroxyethoxyethyl)phthalate using di‐n‐butyltin dilaurate as a catalyst. The PUs were well characterized by FTIR, ¹H, and ¹³C NMR, solid‐state ¹³C‐CP‐MAS NMR, viscosity, solubility, elemental, and X‐ray diffraction studies. Thermal properties of the polymers were also studied by using thermogravimetric analysis and differential scanning calorimetry. The antibacterial activities of these polyurethanes have also been investigated by using the agar diffusion method. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 288–295, 2004     

Studies on polyurethanes and polyurethane–ureas derived from divalent metal salts of mono(hydroxybutyl) hexolate

Divalent metal salts of mono(hydroxybutyl)hexolate [M(HBH)₂), M=Ca²⁺, Mn²⁺or Pb²⁺] were synthesized by the reaction of 1,4‐butanediol, 5,6,7,8,10,10‐hexachloro‐3a,4,4a,5,8,8a,9,9a‐octahydro‐5,8‐methanonaphtho‐[2,3‐C]‐furan‐1,3‐dione and divalent metal acetates. Hexamethylene bis [N′‐(1‐hydroxy‐2‐methyl‐prop‐2‐yl)urea] (HBHMPU) and tolylene 2,4‐bis[N ′‐(1‐hydroxy‐2‐methyl‐prop‐2‐yl)urea] (TBHMPU) were synthesized by reacting 2‐amino‐2‐methyl‐propan‐1‐ol with hexamethylene diisocyanate (HMDI) and tolylene 2,4‐diisocyanate (TDI), respectively, in toluene solvent. Flame‐retardant metal‐containing polyurethanes were synthesized by the solution polymerization of HMDI with M(HBH)₂ and the polyurethane–ureas by reacting HMDI with 1:1 mixture of M(HBH)₂ and HBHMPU or TBHMPU, respectively, in DMSO as solvent. The polymers have been characterized by elemental analysis, solubility, viscosity and IR and ¹H NMR spectroscopy. The thermal stability of the polymers has been studied by thermogravimetry. The flame‐retardant property of the polymers has been investigated by measuring limiting oxygen index values. © 2000 Society of Chemical Industry     

Synthesis and coating characteristics of novel calcium‐containing poly(urethane ethers)

Calcium salt of mono(hydroxypentyl)phthalate [Ca(HPP)₂] was synthesized by the reaction of 1,5‐pentanediol, phthalic anhydride, and calcium acetate. Calcium‐containing poly(urethane ethers) (PUEs) were synthesized by the reaction of hexamethylene diisocyanate (HMDI) or toluylene 2,4‐diisocyanate (TDI) with a mixture of Ca(HPP)₂ and poly(ethylene glycol) (PEG₃₀₀ or PEG₄₀₀) with di‐n‐butyltin dilaurate as a catalyst. We synthesized a series of calcium‐containing PUEs with different compositions by taking the molar ratio of Ca(HPP)₂ : PEG₃₀₀ or PEG₄₀₀ : diisocyanate (HMDI or TDI) as 2 : 2 : 4, 3 : 1 : 4, and 1 : 3 : 4 to study the coating properties of the PUEs. Blank PUEs without a calcium‐containing ionic diol were also prepared by the reaction of PEG₃₀₀ or PEG₄₀₀ with HMDI or TDI. The PUEs were well characterized by fourier transform infrared spectroscopy, ¹HNMR, ^?13C‐NMR, solid‐state cross‐polarity/magic‐angle spinning ¹³C‐NMR, viscosity, solubility, and X‐ray diffraction studies. The thermal properties of the polymers were also studied with thermogravimetric analysis and differential scanning calorimetry. The PUEs were applied as a top coat on acrylic‐coated leather, and their physicomechanical properties were also studied. The coating properties of PUEs, including tensile strength, elongation at break, tear strength, water vapor permeability, flexing endurance, cold crack resistance, abrasion resistance, color fastness, and adhesive strength, were better than the standard values. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 710–721, 2004     

Biobased hyperbranched shape‐memory polyurethanes: Effect of different vegetable oils

Hyperbranched polyurethanes were synthesized from poly(ε‐caprolactone) diol as a macroglycol, butanediol as a chain extender, a monoglyceride of a vegetable oil (Mesua ferrea, castor, and sunflower oils separately) as a biobased chain extender, triethanolamine as a multifunctional moiety, and toluene diisocyanate by a prepolymerization technique with the A₂ + B₃ approach. The structure of the synthesized hyperbranched polyurethanes was characterized by ¹H‐NMR and X‐ray diffraction studies. M. ferrea L. seed‐oil‐based polyurethane showed the highest thermal stability, whereas the castor‐oil‐based one showed the lowest. However, the castor‐oil‐based polyurethane exhibited the highest tensile strength compared to the other vegetable‐oil‐based polyurethanes. All of the vegetable‐oil‐based polyurethanes showed good shape fixity, although the castor‐oil‐based polyurethane showed the highest shape recovery. Thus, the characteristics of the vegetable oil had a prominent role in the control of the ultimate properties, including the shape‐memory behaviors, of the hyperbranched polyurethanes. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39579.     

Synthesis,characterization, and preliminary antimicrobial evaluation of bisphenol‐A formaldehyde resin coordinated with transition metal complexes of ethylenediamine

Coordination polymers containing bisphenol‐A, formaldehyde, and transition metal complexes of ethylenediamine [M(en)₂] were synthesized by the reaction of bisphenol‐A, formaldehyde, and M(en)₂ complex in alkaline medium, using M for Fe⁺³, Co⁺², Ni⁺², Cu⁺², and Zn⁺². The materials were characterized by elemental analysis, FTIR, UV–Vis, ¹H‐NMR spectra, TGA, and magnetic susceptibility measurement. The geometry of the central metal ions was determined by electronic spectral studies and magnetic moment measurement. The M N and C N bonds were confirmed by the IR spectra of the polychelates. The ¹H‐NMR spectra of the chelating resins confirmed polycondensation with well‐defined peaks for bridging methylene functions. Complexation studies with transition metal ions revealed effective coordination of the bisphenol‐A formaldehyde resin. The antimicrobial activities of these chelated resins were screened against E. coli, S. dysantrea (bacteria), and C. albicans, A. niger (fungi) by using agar well diffusion method. All the polymeric chelates show promising antimicrobial activities. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis,characterization, metal sorption,and biological activity of poly(N‐heterocylic acrylamide)

N‐heterocyclic acrylamide monomers were prepared and then transferred to the corresponding polymers to be used as an efficient chelating agent. Polymers reacted with metal nitrate salts (Cu²⁺, Pb²⁺_, Mg²⁺, Cd²⁺, Ni²⁺, Co²⁺_, Fe²⁺) at 150°C to give metal‐polymer complexes. The selectivity of the metal ions using prepared polymers from an aqueous mixture containing different metal ion sreflected that the polymer having thiazolyl moiety more selective than that containing imidazolyl or pyridinyl moieties. Ion selectivity of poly[N‐(benzo[d]thiazol‐2‐yl)acrylamide] showed higher selectivity to many ions e.g. Fe³⁺, Pb²⁺, Cd²⁺, Ni²⁺, and Cu²⁺. While, that of poly[N‐(pyridin‐4‐yl)acrylamide] is found to be high selective to Fe³⁺ and Cu²⁺ only. Energy dispersive spectroscopy measurements, morphology of the polymers and their metallopolymer complexes, thermal analysis and antimicrobial activity were studied. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42712.     

Preparation and characterization of novel optically active polyurethanes containing 1,1′‐binaphthol

Novel optically active polyurethanes (BPUs) based on chiral 1,1′‐binaphthol were synthesized via direct hydrogen transfer addition polymerization. The polymers were analyzed by FTIR, ¹H NMR, DSC‐TGA, CD spectra.The results showed that the specific rotation [α]²⁵_D were ?78.0° and +54.6° for the S‐BPU and R‐BPU respectively, and these polymers showed better thermal stability. The circular dichroism spectra of the chiral polymers were almost identical except that they gave opposite signals at each wavelength, and the infrared emissivity values of the S‐BPU and R‐BPU were 0.618 and 0.682, they displayed low infrared emissivity. Meantime the polymers implanted with PEG group exhibit better solubility, however thermal stability reduced to some extent. Some properties of the new optically active polyurethanes were reported. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Polyurethanes with monodisperse rigid segments based on a diamine–diamide chain extender

Polyether(bisurethane‐bisurea‐bisamide)s (PEUUA) based on poly(tetramethylene oxide) (PTMO) were synthesized by chain extension of PTMO endcapped with a diisocyanate (DI), and a diamine–diamide extender. The prepolymers were PTMOs with molecular weights between 1270 and 2200 g mol^?1, either endcapped with 4,4′‐diphenylmethane diisocyanate (MDI), 2,4‐toluene diisocyanate (2,4‐TDI), or 1,6‐hexane diisocyante (HDI) and with a low content of free diisocyanate (<0.1 wt %). The diamine–diamide (6A6) extender was based on hexamethylene diamine (6) and adipic acid (A). In this way, segmented polyurethanes with monodisperse rigid segments (DI‐6A6‐DI) were obtained. The PEUUAs were characterized by DSC as well as temperature‐dependent FTIR and DMTA. The mechanical properties of the polymers were evaluated by compression set and tensile test measurements. The polyurethanes with monodisperse rigid segments displayed low glass transition temperatures, almost temperature‐independent rubbery plateaus and sharp melting temperatures. The crystallinities of the hard segments were 70–80% upon heating and 40–60% upon cooling. The rate of crystallization was moderately fast as the supercooling (T_m ? T_c) was in the order 36–54°C. The polyurethanes based on HDI had a much higher rubber modulus as compared to the MDI and 2,4‐TDI‐based polymers, because of a higher degree of crystallinity and/or a higher aspect ratio of the crystallites. The HDI residues are flexible and not sterically hindered and could therefore be more easily packed than MDI or 2,4‐TDI residues. Polyurethanes with monodisperse DI‐6A6‐DI hard segments have interesting properties. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Thermally stable polyurethane‐ureas and copolyurethane‐ureas containing zinc and nickel dihydroxysaltrien complexes

New 4,4′‐dihydroxysaltrien metal complexes, (MOHSal₂trien, where M = Zn and Ni) were synthesized and used for the synthesis of metal‐containing polyurethane‐ureas and copolyurethane‐ureas. MOHSal₂trien underwent polymerization reaction with two diisocyanates, namely 4,4′‐diphenylmethane diisocyanate (MDI) and isophorone diisocyanate (IPDI) to yield polyurethane‐ureas. Copolyurethane‐ureas were synthesized by the reaction between MOHSal₂trien, MDI, and diamines or dialcohols. The diamines or dialcohols employed were 4,4′‐methylenedianiline (MDA), hexamethylenediamine (HMA), bisphenol A (BPO), and hexamethylene glycol (HMO). The polymers were characterized by IR, NMR, elemental analysis, XRD, solubility, and viscosity. Thermal stability and flammability of polymers were studied by thermogravimetric analysis (TGA) in air and by measuring limiting oxygen index (LOI) values, respectively. It was found that the resulting metal‐containing polyurethane‐ureas and copolyurethane‐ureas exhibited good thermal stability. Among all metal‐containing polyurethane‐ureas, NiOHSal₂trien‐MDI was the most thermally stable polymer with char yield of 55% at 600°C. Solubility in DMSO of zinc‐containing copolyurethane‐ureas based on dialcohols was greatly improved when compared with those of zinc‐ and nickel‐containing polyurethane‐ureas. ZnOHSal₂trien‐MDI‐BPO and ZnOHSal₂trien‐MDI‐HMO gave high char yield of 46% at 600°C, which is almost comparable with that of NiOHSal₂trien‐MDI. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Early development of a biodegradable energetic elastomer

The expected depletion of oil resources and a greater awareness for the environmental impact of plastic products have created a strong interest toward energetic polymers that are not only biodegradable but also obtainable from renewable resources. In this work, a copoly(ester/ether) was synthesized from polyepichlorohydrin and sebacoyl chloride using pyridine as a Lewis‐base catalyst. The chlorinated polymer was azidified with NaN₃ in dimethyl sulfoxide solutions. The success of the reaction was confirmed by ¹H‐NMR, ¹³C‐NMR, and Fourier‐transform infrared spectroscopy. Two types of polyurethane networks were synthesized from the nonenergetic and the energetic copolymers, adding polycaprolactone triol and using L ‐lysine diisocyanate as a nontoxic curing agent. The two resulting polyurethanes were soft thermoset elastomers. The polyurethanes were chemically and mechanically characterized, and their biodegradability was evaluated in compost at 55°C. The nonenergetic and the energetic polyurethanes showed a glass‐transition temperature of −14°C, and −23°C, respectively. The weight loss of the polyurethanes during the composting experiments was monitored. It increased almost linearly with time for both materials. After 20 days, the nonenergetic samples lost about 50% of their mass because of the biodegradation mechanism. Instead, the energetic elastomers lost only about 25% of their initial mass after 25 days. The experimental results revealed that the azide pendant group in the soft segment (the polyether segments) is the main factor that controls the physical, mechanical, and degradation properties of these polyurethane networks. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis,characterization, and acoustic properties of new soluble polyurethanes based on 2,2′‐[1,4‐phenylenebis(nitrilomethylylidene)diphenol and 2,2′‐[4,4′‐methylene‐di‐2‐methylphenylene‐1,1′‐bis(nitrilomethylylidene)]diphenol

Eight novel polyurethanes based on 2,2′‐[1,4‐phenylenebis(nitrilomethylylidene)]diphenol and 2,2′‐[4,4′‐methylene‐di‐2‐methylphenylene‐1,1′‐bis(nitrilomethylylidene)]diphenol acting as hard segments with two aromatic and two aliphatic diisocyanates (4,4′‐diphenylmethane diisocyanate, toluene 2,4‐diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate) were prepared and characterized with Fourier transform infrared, UV spectrophotometry, fluorescence spectroscopy, ¹H‐NMR and ¹³C‐NMR spectroscopy, thermogravimetric analysis, and differential thermal analysis. All the polyurethanes contained domains of semicrystalline and amorphous structures, as indicated by X‐ray diffraction. The acoustic properties and solubility parameters were calculated with the group contribution method. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Synthesis and characterization of poly(urethane‐ester)s based on calcium salt of mono(hydroxybutyl)phthalate

Calcium‐containing poly(urethane‐ester)s (PUEs) were prepared by reacting diisocyanate (HMDI or TDI) with a mixture of calcium salt of mono(hydroxybutyl)phthalate [Ca(HBP)₂] and hydroxyl‐terminated poly(1,4‐butylene glutarate) [HTPBG₁₀₀₀], using di‐n‐butyltin‐dilaurate as catalyst. About six calcium‐containing PUEs having different composition were synthesized by taking the mole ratio of Ca(HBP)₂:HTPBG₁₀₀₀:diisocyanate (HMDI or TDI) as 3:1:4, 2:2:4, and 1:3:4. Two blank PUEs were synthesized by the reaction of HTPBG₁₀₀₀ with diisocyanate (HMDI or TDI). The polymers were characterized by IR, ¹H NMR, Solid state ¹³C‐CP‐MAS NMR, TGA, DSC, XRD, solubility, and viscosity studies. The T_g value of PUEs increases with increase in the calcium content and decreases with increase in soft segment content. The viscosity of the calcium‐containing PUEs increases with increase in the soft segment content and decreases with increase in the calcium content. X‐ray diffraction patterns of the polymers show that the HMDI‐based polymers are partially crystalline and TDI‐based polymers are amorphous in nature. The dynamic mechanical analysis of the calcium‐containing PUEs based on HMDI shows that with increase in the calcium content of polymer, modulus (g′ and g″) increases at any given temperature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1720–1727, 2006     

Thermally stable polyureas and poly(urea‐imide)s containing zinc and nickel napthtrien complexes

Two new napthtrien metal complexes, MNapth₂trien; where M = Zn and Ni, were synthesized and used for the synthesis of metal‐containing polyureas and poly(urea‐imide)s. MNapth₂trien underwent polymerization reaction with two diisocyanates, namely, 4,4′‐diphenylmethane diisocyanate and isophorone diisocyanate to yield polyureas. Poly(urea‐imide)s were obtained by the synthesis of metal‐containing isocyanate‐terminated polyurea prepolymers from the reaction between MNapth₂trien and excess diisocyanates, which could then undergo further reaction with different dianhydrides. The dianhydrides used were pyromellitic dianhydride and benzophenone‐3,3′,4,4′‐tetracarboxylic dianhydride. The polymers were characterized by infrared, nuclear magnetic resonance, elemental analysis, X‐ray diffraction, solubility, and viscosity. Glass transition temperature of the polymers was obtained from differential scanning calorimetry and dynamic mechanical thermal analysis. Thermal stability of polymers was studied by thermogravimetric analysis in air. It was found that the resulting metal‐containing polymers exhibited good thermal stability. Initial decomposition temperatures of the polymers depend on the amount of MNapth₂trien in the polymer composition. Char yields of metal‐containing poly(urea‐imide)s are higher than those of metal‐containing polyureas. Most metal‐containing polymers show good solubility in organic solvents. Shore D hardness test indicates that metal‐containing poly(urea‐imide)s are hard materials. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis,characterization of novel dihydrazide containing polyurethanes based on N1,N2‐bis[(4‐hydroxyphenyl)methylene]ethanedihydrazide and various diisocyanates

Four novel types of polyurethanes (PUs) were prepared from N¹,N²‐bis[(4‐hydroxyphenyl)methylene]ethanedihydrazide with two aromatic diisocyanates (4,4′‐diphenylmethane diisocyanate and tolylene 2,4‐diisocyanate) and two aliphatic diisocyanates (isophorone diisocyanate and hexamethylene diisocyanate). The chemical structure of both diol and PUs was confirmed by UV–vis, fluoroscence, FTIR, ¹H NMR, and ¹³C NMR spectral data. DSC data show that PUs have multiple endotherm peak. X‐ray diffraction revealed that the PUs contained semicrystalline and amorphous regions that varied with the nature of the backbone structures. PUs were soluble in polar aprotic solvents. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Synthesis and characterization of alternating copolymers containing bipyridine and phenylene vinylene for fluorescent chemosensors

Alternating copolymers containing bipyridine and phenylene vinylene were synthesized through a Wittig condensation reaction of their corresponding diphosphonium salts and dialdehydes. The molecular weights of the resulting polymers were relatively low because of the low solubility in the reaction solvents. The optical properties of the polymers were substantially affected by the repeating units of phenylene vinylene. The absorption spectra of the copolymers in the solid state exhibited a bathochromic shift compared to those carried out in solution. The effective conjugation length could be extended with the addition of Cu²⁺, Ni²⁺, and Zn²⁺ ions into the polymer solutions in a 1 : 1 ratio of the bipyridine to the phenylene vinylene units. All of the polymer solutions behaved as a turn‐off fluorescent chemosensor upon the addition of a variety of the metal ions. The sensing behavior to various metal ions revealed that the polymers were highly sensitive to the Cu²⁺, Ni²⁺, and Zn²⁺ ions. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42795.     

Renewable resource modified polyol derived aliphatic hyperbranched polyurethane as a biodegradable and UV‐resistant smart material

Renewable resource tailored tough, elastomeric, biodegradable, smart aliphatic hyperbranched polyurethanes were synthesized using castor oil modified polyol containing fatty amide triol, glycerol, diethanolamine and monoglyceride of sunflower oil via an A_x + B_y (x , y ≥ 2) approach. To the best of our knowledge, this is the first report of the synthesis of solely aliphatic hyperbranched polyurethanes by employing renewable resources. The synthesized polyurethanes were characterized by Fourier transform infrared, NMR and XRD techniques. The hyperbranched polyurethanes exhibited good mechanical properties, especially elongation at break (668%), toughness (32.16 MJ m^?3) and impact resistance (19.02 kJ m^?1); also high thermal stability (above 300 °C) and good chemical resistance. Also, the hyperbranched polyurethanes were found to show adequate biodegradability and significant UV light resistance. Moreover, they demonstrated excellent multi‐stimuli‐driven shape recovery ability (up to 97%) under direct sunlight (10⁵ lux), thermal energy (50 °C) and microwave irradiation (450 W). The performance of the hyperbranched polyurethanes was compared with renewable resource based and synthetic linear polyurethane to judge the superiority of the hyperbranched architecture. Therefore, these new aliphatic macromolecules hold significant promise as smart materials for advanced applications. © 2017 Society of Chemical Industry     

1H nuclear magnetic resonance study of polyurethane prepolymers from toluene diisocyanate and polypropylene glycol

Polyurethane prepolymers prepared from toluene 2,4‐diisocyanate, toluene 2,6‐diisocyanate, and polypropylene glycol with a ratio between the isocyanate and hydroxyl groups equal to 2 were analyzed by ¹H nuclear magnetic resonance (NMR) spectroscopy in acetone‐d₆. Different temperatures and concentrations were used. Toluene 2,4‐dimethylurethane and toluene 2,6‐dimethylurethane were synthesized and used as model compounds to assign prepolymers signals. Measurements of spin–lattice relaxation time T₁ by “inversion recovery” experiments were carried out on toluene 2,4‐diisocyanate, toluene 2,6‐diisocyanate, toluene 2,4‐dimethylurethane, toluene 2,6‐dimethylurethane, and polyurethane prepolymers. Differences in T₁ times were used to interpret prepolymers spectra, by means of the strong observed effect on protons due to the presence of adjacent isocyanate groups. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 347–357, 2003     

Total replacement of solvent in polyurethane synthesis using carbon dioxide soluble 1,3‐dichlorodistannoxane catalysts

This work demonstrates catalytic synthesis of polyurethanes using 1,3‐dichlorodistannoxane catalysts ( 1 ) in carbon dioxide (CO₂) and carbon dioxide expanded liquids (CXL). Catalytic polyurethane synthesis was also performed in pure organic solvent (dimethylformamide) for comparison. In this study, mainly, 4, 4′‐methylene‐bis‐(phenyl isocyanate) (MDI) as the diisocyanate precursor and ethylene glycol (EG) as the diol precursor were used for polyurethane synthesis. In addition to MDI, hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI), and p‐isocyanatobenzylisocyanate (PIBI) were also used for polyurethane synthesis with different diols or triol in CO₂. Polyurethanes with a molecular weight ranging from 3000 to 70,000 were synthesized depending upon the combination of diisocyanate and diol used. Comparable yields of polyurethanes were obtained using an all butyl group substituted ( 1a ) catalyst in CO₂ (55 bars, 50°C) and in DMF (50°C). Additionally, the yield and polydispersity index (PDI) of polymer formed in neat CO₂ was comparable with those synthesized in the largely used organic solvent DMF. Interestingly, catalyst 1a in CXL (55 bars, 50°C) gave higher yields, and polymers with lower PDI (1.19). Reactions carried out in scCO₂ at 145 bars using PIBI and EG were found to be about three times faster than the reaction carried out in DMF. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Synthesis and characterization of novel Schiff base polyurethanes

Eight different types of novel polyurethanes (PUs) were synthesized through the polyaddition reaction of 4,4′‐(ethane‐1,2‐diylidenedinitrilo)diphenol and 4,4′‐(pentane‐1,5‐diylidenedinitrilo)diphenol with four different diisocyanates: 4,4′‐diphenylmethane diisocyanate, toluene 2,4‐diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate. The resulting PUs were soluble in polar, aprotic solvents. Structures of the diols and PUs were established with ultraviolet–visible, fluorescence, Fourier transform infrared (FTIR), ¹H‐NMR, and ¹³C‐NMR spectroscopy data. FTIR and NMR spectral data indicated the disappearance of both hydroxyl and isocyanate groups in the PUs. The thermal properties were investigated with thermogravimetry and differential scanning calorimetry. The weight losses, glass transitions, onset temperatures, and crystalline melting temperatures were measured. All the PUs exhibited semicrystalline and amorphous morphologies, as indicated by X‐ray diffraction. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009.     

Synthesis and characterization of novel polyurethanes based on N1,N4‐bis[(4‐hydroxyphenyl)methylene]succinohydrazide hard segment

This article deals with the synthesis and characterization of novel polyurethanes (PUs) by the reaction between two aromatic diisocyanates (4,4′‐diphenylmethane diisocyanate and tolylene 2,4‐diisocyanate) and two aliphatic diisocyanates (isophorone diisocyanate and hexamethylene diisocyanate) with N¹,N⁴‐bis[(4‐hydroxyphenyl)methylene]succinohydrazide, which acted as hard segment. UV–vis, FTIR, ¹H NMR, ¹³C NMR, and DSC/TGA analytical technique has been used to determine the structural characterization and thermal properties of the hard segmented PUs. X‐ray diffraction revealed that PUs contained semicrystalline and amorphous regions that varied depending upon the nature of the backbone structures. PUs were soluble in polar aprotic solvents. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008