Study on synthesis and thermal properties of polyurethane–imide copolymers with multiple hard segments

Different multiple hard segment polyurethane–imide copolymers (MHPUI) were synthesized and characterized. FTIR spectroscopy confirmed the characteristic absorption of the MHPUI copolymer. The difference in the imide group FTIR absorption bands in different MH segment PUI copolymers was found in this study and was explained by the different MH segment types, hard segment contents, and hard segment rigidity with different interactions of the molecular chains. The hard segment interaction in MHPUI with an increase of the structure rigidity of the short hard segments is strengthening. The DSC analysis revealed that the glass‐transition temperature of the soft segment of PUI rose in value from ?42 to ?3.4°C with the introduction of MH and different MH segments. The DSC results suggest that the soft segment is more compatible with the hard segment rigidity increase. The TGA results showed the hard segment structure symmetry has a more important role in the MHPUI thermal stability. Every sample containing symmetrical structure short hard groups (4,4′‐diphenylmethane diisocyanate or 4,4′‐diaminodiphenylmethane) is more thermally stable than that with worse symmetry structure groups (2,4‐toluene diisocyanate or 3,3′‐dichloro‐4,4′‐diamino‐diphenylmethane). The three‐step mechanism of PUI thermal degradation was further verified by the TGA study. The thermally unstable group was confirmed as urethane or a urea–urethane segment. The TGA results showed that MHPUI copolymers with higher separation of the soft–hard phase have higher thermal stability. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2206–2215, 2002     

Synthesis and characterization of metal‐containing polyurethanes with antibacterial activity

Metal salts of mono(hydroxypentyl)phthalate [M(HPP)₂, where M is Ca²⁺, Cd²⁺, Pb²⁺, or Zn²⁺] were synthesized by the reaction of 1,5‐pentane diol, phthalic anhydride, and metal acetate. A new series of metal‐containing polyurethanes containing ionic links in the main chain were synthesized by the reaction of hexamethylene diisocyanate or toluylene 2,4‐diisocyanate with the M(HPP)₂ salts. The structures of the monomers and polymers were confirmed with infrared, ¹H‐NMR, and ¹³C‐NMR spectra and elemental analysis. The polymers were also characterized with thermogravimetric analysis, differential scanning calorimetry, and solubility and viscosity measurements. The antibacterial activity of these polyurethanes was investigated with the agar diffusion method. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1194–1206, 2002     

Synthesis of polyurethane–imide (PU–imide) copolymers with different dianhydrides and their properties

This study reports the synthesis of polyurethane–imide (PU–imide) copolymers using 4,4′-diphenylmethane diisocyanate (MDI) polytetramethylene glycols (PTMGs) and different aromatic dianhydrides. Differential scanning calorimetry (DSC) results indicate that PU–imide copolymers had two phase structures containing four transition temperatures (T_gs, T_ms, T_gh and T_mh). However, only PU–imide copolymers were formed by soft PTMG(2000) segments possessing a T_ms (melting point of soft segment). When different aromatic dianhydrides were introduced into the backbone chain of the polyurethane, although the T_gs (glass transition temperature of the soft segment) of some of PU–imide copolymers did not change, the copolymers with long soft segments had low T_gs values. The T_gh (glass transition temperature of hard segment) values of PU–imide copolymers were higher than that of polyurethane (PU). In addition, the high hard segment content of PU–imide copolymer series also had an obvious T_mh (melting point of hard segment). According to thermogravimetric analysis (TGA) and differential thermogravimetric analysis (DTGA), the PU–imide copolymers had at least two stages of degradation. Although the T_di (initial temperature of degradation) depended on the hard segment content and the composition of hard segment, the different soft segment lengths did not obviously influence the T_di. However, PU–imide copolymers with a longer soft segment had a higher thermal stability in the degradation temperature range of middle weight loss (about T_d 5%–50%). However, beyond T_d 50% (50% weight loss at temperature of degradation), the temperature of degradation of PU–imide copolymers increased with increasing hard segment content. Mechanical properties revealed that the modulus and tensile strength of PU–imide copolymers surpassed those of PU. Wide angle X-ray diffraction patterns demonstrated that PU–imide copolymers are crystallizable. © 1999 Society of Chemical Industry     

新型阻燃剂磷酸单(1-氯-2-羟基丙基)酯及其锑合物的合成

以三氯化铝为催化剂,环氧氯丙烷、磷酸为原料合成了磷酸单（１－氯－２－羟基丙基）酯并以磷酸单（１－氯－２－羟基丙基）酯和三氧化二锑为原料合成了其锑合物。实验结果表明,以甲苯为溶剂,在反应温度为９０℃,时间２ ｈ,原料配比为ｎ（环氧氯丙烷）∶ｎ（磷酸）＝ １∶１．２ 条件下,酯的收率为８２．５％ 。锑合物的合成条件为：温度９２℃,反应时间为４ ｈ,以二甲亚砜为溶剂,产品收率为８５．６％ 。     

Preparation and characterization of thermoplastic polyurethane–urea and carboxylated acrylonitrile butadiene rubber blend nanocomposites

This study deals with the preparation and characterization of novel thermoplastic polyurethane–urea (TPUU) and carboxylated acrylonitrile butadiene rubber (XNBR) blends. Blends of different compositions were prepared in tetrahydrofuran using a solution technique, following an ultra‐sonication. The chemical reaction between the two inherently immiscible blend phases was determined with the help of Fourier transform infrared‐attenuated total reflectance (FTIR‐ATR) spectroscopy and ¹H‐nuclear magnetic resonance (¹H‐NMR) spectroscopy. The identification of the new peaks in the FTIR‐ATR spectra corroborates the existence of chemical reaction between the carboxylic functional group of XNBR and the amide group of the TPUU. In addition, an increase in the network crosslink density of the blend investigated using ¹H‐NMR spectroscopy further supports the occurrence of the chemical reaction between the XNBR and the TPUU. The scanning and transmission electron micrographs of the blend morphology show a uniform dispersion of the minor TPUU phase in the XNBR. Furthermore, the existence of a single glass transition peak also confirms the enhancement in the interfacial miscibility. Additionally, the incorporation of 5 wt % of organomodified montmorillonite nanoclay improves the mechanical properties to a considerable extent in comparison with the unfilled blend elastomeric material. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis and evaluation of the thermal properties of biosourced poly(ether)ureas and copoly(ether)ureas from 1,4:3,6‐dianhydrohexitols

A new series of poly(ether)ureas were prepared by solution polyaddition of three diamines based on 1,4:3,6‐dianhydrohexitols with three types of diisocyanate. The corresponding poly(ether)ureas were obtained with high yields. They were characterized by various analytical techniques (NMR, TGA and differential thermal analysis, DSC). NMR spectroscopy allowed us to confirm structure type and to optimize reaction conditions and DSC proved the high thermal properties of the products obtained (T_g and T_m in the range 126 ? 158 °C and 235 ? 330 °C respectively). Then, copoly(ether)ureas partially based on commercial diamines were synthesized in order to reduce polymer cost and tune their thermal behaviour. The reactivity of both diamines was evaluated by their incorporation in the polymer by means of NMR spectra. Then their thermal properties were compared with fully commercial diamine based polyureas by DSC studies. © 2014 Society of Chemical Industry     

Effect of selected boroorganic compounds on thermal and heat properties of rigid polyurethane–polyisocyanurate foams

The effects of three selected borates {tri(hydroxypropyl), tri[(3‐chloro‐2‐hydroxy‐1‐propoxy)‐1‐methylethyl], tri[(3‐chloro‐2‐hydroxy‐1‐propoxy)propyl]} on the heat and thermal properties of rigid polyurethane–polyisocyanurate foams was studied. Increasing the amount of tri(hydroxypropyl) borate and tri[(3‐chloro‐2‐hydroxy‐1‐propoxy)propyl] borate in the foam composition from 0.1 to 0.4 chemical equivalents caused an increase in the softening point, the temperature of the first decrement of foam mass, the extrapolated temperature of the main decrement of the foam mass, and the temperature of the highest rate of the mass decrement. When tri[(3‐chloro‐2‐hydroxy‐1‐propoxy)‐1‐methylethyl] borate was added to the foam compositions, the softening point decreased but the temperatures characterizing their thermal resistance were higher in comparison with the standard foam. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 768–771, 2006     

Synthesis and characterization of novel optically active poly(imide–urethane)s derived from N,N′‐(pyromellitoyl)‐bis‐(L‐leucine) diisocyanate and aromatic diols

N,N′‐(Pyromellitoyl)‐bis‐(L ‐leucine) diacid was reacted with ethyl chloroformate in the presence of triethylamine followed by reaction with activated sodium azide and gave N,N′‐(pyromellitoyl)‐bis‐(L ‐leucine) diacylazide in high yield. This diacylazide was heated in dry benzene and gave the unstable N,N′‐(pyromellitoyl)‐bis‐(L ‐leucine) diisocyanate ( 5 ) in quantitative yield. Thus, diisocyanate 5 was generated in situ and polycondensation reaction of this monomer with several aromatic diols, such as 4,4′‐dihydroxybiphenyl, 1,4‐hydroquinone, bisphenol A, phenolphthalein and 1,4‐dihydroxyanthraquinone, was performed in dry toluene under refluxing in the presence of 1,4‐diazabicyclo[2.2.2]octane (triethylenediamine) as a catalyst. The polymerization reactions proceeded within 48 h, producing a series of optically active poly(imide–urethane)s with good yield and moderate inherent viscosity in the range 0.18–0.28 dl g^?1. All of the above polymers were fully characterized by infrared spectra, elemental analyses and specific rotation. Some structural characterization and physical properties of these optically active poly(imide–urethane)s are reported Copyright © 2003 Society of Chemical Industry     

Fire retardant synergism of hydroquinone bis(diphenyl phosphate) and novolac phenol in acrylonitrile–butadiene–styrene copolymer

Hydroquinone bis(diphenyl phosphate) (HDP) has been adopted to prepare acrylonitrile–butadiene–styrene copolymer (ABS)/HDP/novolac phenol (NP) composites. The limiting oxygen index (LOI) of ABS/HDP/NP composites is tested in this paper. The LOI value first grows with increasing ratio of HDP to NP, after reaching its maximum it decrease with further increasing ratio. The synergistic effect of HDP and NP exerted on the microstructure and the flame retardancy of ABS/HDP/NP composites are carefully analyzed by thermogravimetric analysis (TGA), cone calorimeter (CCT), scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). The results of CCT show that the synergistic action of HDP and NP reduces its heat release rate and smoke production rate. The results of TGA and SEM demonstrated that the introduction of NP and HDP is conducive to the improvement of the thermal stability and the formation of the intumescent char with homogeneous cavities and holes. The EDS results indicate that the introduction of NP could help retain phosphorus in the chars. As a result, the synergistic action of HDP and NP is favorable to the enhancement of flame retardancy of ABS/HDP/NP composites. Copyright © 2014 John Wiley & Sons, Ltd.     

Studies on various divalent metal complexes of poly(2-hydroxy-4-acryloyloxybenzophenone) in aqueous medium

2-Hydroxy-4-acryloyloxybenzophenone (2H4ABP) prepared by reacting acryloyl chloride with 2,4-dihydroxybenzophenone, was polymerized in 2-butanone at 65°C using benzoyl peroxide as initiator. Polychelates were obtained in the alkaline solution of poly(2H4ABP) with aqueous solutions of metal ions such as Ni(II), Mn(II), Co(II), Ca(II), Cd(II) and Zn(II). The polymer and polychelates were characterized by elemental analyses and spectral studies. Elemental analyses of the polychelates suggest that the metal-to-ligand ratio is 1: 2. The IR spectral data of the polychelates indicate that the metals were coordinated through the oxygen of the keto group and oxygen of the phenolic −OH group. The diffuse reflectance spectra, EPR and magnetic moments studies reveal that the polychelates of Cu(II) complex are square planar, and Ni(II), Mn(II) and Co(II) complexes are octahedral, while Ca(II), Cd(II) and Zn(II) complexes are tetrahedral. X-ray diffraction studies revealed that the polychelates are highly crystalline. The thermal and electrical properties of polymer and polymer–metal complexes are discussed. © 1998 SCI.     

Characterization of poly(trimethylene/butylene terephthalate) copolymer prepared by the copolycondensation of bis(3‐hydroxypropyl terephthalate) and bis(4‐hydroxybutyl terephthalate)

Homopolymers and copolymers were synthesized by polycondensation and copolycondensation, with varying feed ratios of bis(3‐hydroxypropyl terephthalate) (BHPT) and bis(4‐hydroxybutyl terephthalate) (BHBT) at 270°C. In addition, in the mol ratio of 1:1, copoly(trimethylene terephthalate/butylene terephthalate) [P(TT/BT)], with reaction times of 5, 10, 20, 30, and 60 min, was synthesized to identify the chain‐growth process of the copolymers. From differential scanning calorimetry (DSC) data, it was found that a random copolymer might be formed during copolycondensation. The molecular structure of copolymers, formed through the interchange reaction of BHPT and BHBT, was investigated using carbon nuclear magnetic resonance spectroscopy (¹³C‐NMR). We calculated the sequence‐length distributions of trimethylene and butylene sequences and randomness in the copolymers using ¹³C‐NMR data. From the values of the number‐average sequence length calculated, it was determined that a random copolymer was produced: This result coincides with previous DSC data. The lateral spacing of the unit cell of the copolymer increased slowly when the mol percent of one monomer was increased to that of the other monomer, indicating broadening of the unit cell by lateral distortion. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2200–2205, 2003     

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     

Synthesis of new poly(amide–imide)s derived from trimellitylimido‐L‐phenylalanine

N‐Trimellitylimido‐L ‐phenylalanine was prepared from the reaction of 1,2,4‐benzenetricarboxylic anhydride with L ‐phenylalanine in N,N‐dimethylformamide solution at refluxing temperature. The direct polycondensation reaction of the monomer imide‐diacid with 4,4′‐diaminodiphenylsulfone, 4,4′‐diaminodiphenylmethane, 1,4‐phenylenediamine, 1,3‐phenylenediamine, 2,4‐diaminotoluene, 4,4′‐diaminodiphenylether and benzidine was carried out in a medium consisting of triphenyl phosphite, N‐methyl‐2‐pyrrolidone, pyridine and calcium chloride. The resulting poly(amide–imide)s, PAIs, having inherent viscosities of 0.21–0.45 dlg^?1 were obtained in high yield. All of the above compounds were fully characterized by IR spectroscopy and elemental analyses. The optical rotation of all PAIs has also been measured. Some structural characterization and physical properties of these new optically active PAIs are reported. © 2001 Society of Chemical Industry     

Effect of nitrogen–phosphorus fire retardant blended with Mg(OH)2/Al(OH)3 and nano‐SiO2 on fire‐retardant behavior and hygroscopicity of poplar

The aim of the study was to screen any possible synergistic effects related to the combination of nitrogen–phosphorus fire retardant and Mg(OH)₂/Al(OH)_3. This combination is used to improve fire performance, especially smoke suppression of poplar through ultrasonic wave impregnation after microwave treatment. In this study, nano‐SiO₂ was used to impregnate poplar treated with nitrogen–phosphorus fire retardant and form a hydrophobic layer on wood cells in order to improve hygroscopicity and reduce water uptake. Cone tests and thermal analysis showed that poplar treated with blended fire retardant had improved behavior. Results show that a 20% and 25% nitrogen–phosphorus fire‐retardant solution (blended by adding 10% Mg(OH)₂/Al(OH)₃ based on the dry weight of nitrogen–phosphorus fire retardant) was more effective for smoke suppression. The heat release rate, total heat release, and total smoke production of a 25% nitrogen–phosphorus fire‐retardant solution blended by adding 10% Mg(OH)₂/Al(OH)₃ showed significant reduction. The char residual yield showed a marked increase to 35.5%. Fourier transform infrared analysis suggested a –CH₂–Si–CH₂– and Si–O–C stretching vibration in nano‐SiO₂ treated poplar, which greatly decreased the hygroscopicity of fire‐retardant‐treated poplar. Copyright © 2014 John Wiley & Sons, Ltd.     

Synthesis and properties of novel aromatic poly(ester–amide)s derived from 1,5‐bis(3‐aminobenzoyloxy)naphthalene and aromatic dicarboxylic acids

A new naphthalene‐ring‐containing bis(ester–amine), 1,5‐bis(3‐aminobenzoyloxy)naphthalene, was prepared from the condensation of 1,5‐dihydroxynaphthalene with 3‐nitrobenzoyl chloride followed by catalytic hydrogenation. A series of novel naphthalene‐containing poly(ester–amide)s was synthesized by direct phosphorylation polyamidation from this bis(ester–amine) with various aromatic dicarboxylic acids. The polymers were produced in high yields and had moderate inherent viscosities of 0.47–0.81 dL g^?1. The poly(ester–amide) derived from terephthalic acid was semicrystalline and showed less solubility. Other polymers derived from less rigid and symmetrical diacids were amorphous and readily soluble in most polar organic solvents and could be solution‐cast into transparent, flexible and tough films with good mechanical properties. The amorphous poly(ester–amide)s displayed well‐defined glass transition temperatures of between 179 and 225 °C from differential scanning calorimetry and softening temperatures of between 178 and 211 °C from thermomechanical analysis. These poly(ester–amide)s did not show significant decomposition below 400 °C in nitrogen or air. Copyright © 2004 Society of Chemical Industry     

Synthesis and characterization of new thermally stable aromatic copoly(ester–amide)s from diester‐dicarboxylic acids

Two new aromatic diester‐dicarboxylic acids containing furan rings, namely, benzofuro[2,3‐b]benzofuran‐2,9‐dicarboxyl‐bis‐pyridyl ester‐4,4′‐dicarboxylic acid and benzofuro[2,3‐b]benzofuran‐2,9‐dicarboxyl‐bis‐phenyl ester‐4,4′‐dicarboxylic acid were synthesized by the reaction of benzofuro[2,3‐b]benzofuran‐2,9‐dicarbonyl chloride with 6‐hydroxynicotinic acid and 4‐hydroxybenzoic acid, respectively. These monomers were converted to aromatic copoly(ester–amide)s by reaction with various aromatic diamines via direct polycondensation. Polymers were characterized by FTIR and ¹H NMR spectroscopy, thermogravimetry, viscosity and solubility tests. The inherent viscosity of the polymers was in the range 0.23–0.46 dl g^?1 in dimethyl sulfoxide at 30 °C. They dissolved readily in polar solvents at room temperature. They possess a glass‐transition temperature in the range 210–260 °C and exhibit excellent thermal stability. Copyright © 2004 Society of Chemical Industry     

Physical,mechanical, and thermal properties of polyurethanes based on hydroxyalkylated cardanol–formaldehyde resins

Polyurethanes are synthesized using three different hydroxyalkylated cardanol–formaldehyde resins, diphenylmethane diisocyanate (MDI), and a commercial polyol (PPG‐2000). These polyurethanes are found to be tough and crosslinked. A polyurethane prepared using a higher mole ratio of cardanol/formaldehyde of hydroxyalkylated cardanol–formaldehyde resin is found to possess better thermal and mechanical properties than the polyurethane prepared from a lower mole ratio. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 284–288, 2005     

Quantification of response time in poly(vinyl alcohol)–metal complex thermochromic polymeric systems

Thermochromic poly(vinyl alcohol) (PVA)‐based material was synthesized and an extensive study of its thermochromic behavior with respect to response time was carried out. It was observed that it is possible to manipulate the response time by keeping control over chemical and physical parameters. The response time, which is the most important property of a smart material, has in this case been found to be very much influenced by rate of heat transfer into the material. Different compositions of the thermochromic material and their corresponding response time with respect to rate of heat transfer were studied and correlated. First, a theoretical equation was derived and later on it was experimentally verified to quantify the response time in PVA–metal complex‐based thermochromic systems. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4832–4834, 2006     

Synthesis and characterization of new aromatic poly(amide–imide)s based on 4‐aryl‐2,6‐bis(4‐trimellitimidophenyl) pyridines

New diimide–dicarboxylic acids, ie 4‐phenyl‐2,6‐bis(4‐trimellitimidophenyl)pyridine and 4‐p‐biphenyl‐2,6‐bis‐(4‐trimellitimidophenyl)pyridine, were synthesized by the condensation reaction of 4‐phenyl‐2,6‐bis(4‐aminophenyl)pyridine and 4‐p‐biphenyl‐2,6‐bis(4‐aminophenyl)pyridine with trimellitic anhydride in glacial acetic acid or dimethylformamide. The monomers were fully characterized by FT‐IR and NMR spectroscopies, and elemental analyses. A series of novel poly(amide–imide)s with inherent viscosities of 0.68–0.87 dl g^?1 was prepared from the two diimide–diacids with various aromatic diamines by direct polycondensation. The poly(amide–imide)s were characterized by FT‐IR and NMR spectroscopies. The λ_max data for the resulting poly(amide–imide)s were in the range of 260–292 nm. These polymers exhibited good solubilities in polar aprotic solvents. The 10 % weight loss temperatures are above 485 °C under a nitrogen atmosphere. Copyright © 2004 Society of Chemical Industry     

Separation and recovery of gold(III) from base metal ions using melamine–formaldehyde–thiourea chelating resin

Melamine–formaldehyde–thiourea (MFT) chelating resin has been prepared. Au³⁺ ions uptake behavior and selectivity of the chelating resin were investigated by both batch and column methods. MFT resin showed higher affinity toward Au³⁺ compared with base metal ions, Cu²⁺ and Zn²⁺. The highest Au³⁺ uptake values were obtained at pH 2 and Au³⁺ adsorption capacity of the resin was calculated as 48 mg Au³⁺/g resin (0.246 mmol Au³⁺/g resin) by batch method. It was concluded that Au³⁺ ions could be selectively concentrated from the solution including Cu²⁺ and Zn²⁺ base metal ions by column method. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008