New thermoplastic segmented polyurethanes with hard segments derived from 4,4′‐diphenylmethane diisocyanate and methylenebis(1,4‐phenylenemethylenethio)dialcanols

New thermoplastic poly(ether–urethane)s and poly(carbonate–urethane)s were synthesized by a one‐step melt polymerization from poly(oxytetramethylene) diol (PTMO) and poly(hexane‐1,6‐diyl carbonate) diol (PHCD) as soft segments, 4,4′‐diphenylmethane diisocyanate, and 2,2′‐[methylenebis(1,4‐phenylenemethylenethio)]diethanol, 3,3′‐[methylenebis(1,4‐phenylenemethylenethio)]dipropan‐1‐ol or 6,6′‐[methylenebis(1,4‐phenylenemethylenethio)]dihexan‐1‐ol as unconventional chain extenders. The effects of the kind and amount of the polymer diol and chain extender used on the structure and properties of the polymers were studied. The polymers were examined by Fourier transform infrared (FTIR) spectroscopy, X‐ray diffraction analysis, atomic force microscopy, differential scanning calorimetry, thermogravimetric analysis (TGA), TGA coupled with FTIR spectroscopy, and Shore hardness and tensile testing. The obtained high‐molecular‐weight polymers showed elastomeric or plastic properties. Generally, the PTMO‐based polymers exhibited significantly lower glass‐transition temperatures (up to ?48.1 vs ?1.4°C), a higher degree of microphase separation, and ordering in hard‐segment domains in comparison with the corresponding PHCD‐based ones. Moreover, it was observed that the polymers with the PTMO soft segments showed poorer tensile strengths (up to 36.5 vs 59.6 MPa) but higher elongations at break. All of the polymers exhibited a relatively good thermal stability. Their temperatures of 1% mass loss were in the range 270–320°C. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

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     

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     

Synthesis and characterization of aromatic polyesters and copolyesters from 4,4′‐(1‐hydroxyphenylidene)diphenol and 4,4′‐(9‐fluorenylidene)diphenol

Two isophthalic polyesters from 4,4′‐(1‐hydroxyphenylidene)diphenol (BAP/ISO) and 4,4′‐(9‐fluorenylidene)diphenol (BF/ISO), and three different copolyesters containing 75, 50, and 25 mol % of BAP/ISO were synthesized by interfacial polycondensation. This preparation method yielded polymers and copolymers that produced flexible and transparent films when they were cast from solution. Proton NMR spectrometry studies showed that the isophthalic copolyesters were obtained as random copolymers with differences in comonomer composition no larger than 2.5 mol % with respect to the expected compositions. Wide‐angle X‐ray diffraction measurements indicated that all the polyesters and copolyesters were amorphous. The copolyesters showed amorphous patterns with maxima that fell between those of the polyesters. It was also found that thermal properties such as glass‐transition temperature, onset of decomposition temperature, thermal stability, dynamic mechanical storage modulus, and maximum on the α‐transition of the damping factor tan δ of BF/ISO were higher than those of BAP/ISO. The values of these thermal properties in the copolyesters fell between those of the polyesters and were dependent on the amounts of BF/ISO and BAP/ISO present in the copolyester in a linear fashion. Therefore, the thermal properties of a given copolyester can be predicted directly from the comonomers' composition. Overall, it shows that the interfacial polycondensation method is suitable to obtain these copolyesters in a controlled manner and that their properties can be tailored to be between those of the homopolyesters. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2515–2522, 2002     

Preparation and properties of 4,4′‐(hexafluoroisopropylidene) diphenol cured 2,2‐bis(4‐cyanatophenyl) propane

A novel easily curing system of 2,2‐bis(4‐cyanatophenyl) propane(BACY) was prepared by employing 4,4′‐(Hexafluoroisopropylidene) Diphenol (BPAF) as modifier. The curing efficiency of BPAF was evaluated by means of differential scanning calorimetry (DSC) and Fourier translation infrared spectroscopy analysis (FTIR). It was found that the exothermic peak temperature (T_p) was 168 °C when the content of BPAF/BACY was 15/85 by weight, while the temperature of BACY was 215 °C under the same conditions when trace of cobalt(III) acetylacetonate(CoAt(III)) was added. Besides, BPAF/BACY system owned outstanding properties including excellent curing characteristics, high shear strength, remarkable dielectric properties and high thermal stability in contrast to BACY, 4,4′‐(1‐methylethylidene) bisphenol(BPA)/BACY, and nonylphenol(NoP)/BACY systems. Moreover, the properties of cured BPAF/BACY modified by different proportions of BPAF were studied in detail. It was shown that moderate BPAF was conducive to most properties of polycyanurate, and the optimal proportion of BPAF/BACY was 15/85 by weight. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44518.     

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     

Preparation and characterization of novel polyurethanes containing 4,4′‐{oxy‐1,4‐diphenyl bis(nitromethylidine)}diphenol schiff base diol

Four novel segmented polyurethanes (PUs) based on4,4′‐{oxy‐1,4‐diphenyl bis(nitromethylidine)}diphenol (ODBNMD) diol with different diisocyanates such as 4,4′‐diphenylmethane diisocyanate, toluene 2,4‐diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate have been prepared by solution method. The structures of ODBNMD and PUs have been confirmed by Fourier transform infrared (FTIR), nuclear magnetic resonance (¹H‐NMR and ¹³C‐NMR), UV‐visible, and fluorescence spectroscopies. The segmented PUs were further characterized by thermogravimetry (TGA), differential scanning calorimetry (DSC), and wide‐angle X‐ray diffraction. FTIR confirmed hydrogen bonding interactions, whereas TGA and DSC suggested that introduction of aromatic/phenyl ring in the main chain considerably increased the thermal stability. POLYM. ENG. SCI., 54:24–32, 2014. © 2013 Society of Plastics Engineers     

Synthesis,structure, and properties of segmented carborane‐containing polyurethanes

Novel segmented carborane‐containing polyurethane (PUR 2–5) is synthesized from hydroxyl‐terminated carborane‐containing prepolymer (P3) as soft segment and isocyanate‐terminated carborane‐containing prepolymer (P5) as hard segment by different ratio of P3 and P5. The prepared carborane‐containing polyarylesters and polyurethanes (PURs) are characterized by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy (NMR). Their mechanical properties and thermal stability are measured, while the dosage of carborane biphenol is 5–10 wt %, the tensile strength is up to 20 MPa, and thermal gravimetric analyzer (TGA) curves indicate that the carborane group effectively reduces the degradation rate of carborane‐containing polyurethane, which is fairly stable above 300°C and with char yield exceeding 40%. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42227.     

Synthesis and characterization of novel polyurethanes based on 1,3‐bis(hydroxymethyl) benzimidazolin‐2‐one and 1,3‐bis(hydroxymethyl) benzimidazolin‐2‐thione hard segments

Novel polyurethanes (PUs) based on 1,3‐bis(hydroxymethyl) benzimidazolin‐2‐one and 1,3‐bis(hydroxymethyl) benzimidazolin‐2‐thione as hard segments with two aromatic diisocyanates, viz., 4,4′‐diphenylmethane diisocyanate and toluene 2,4‐diisocyanate, were prepared. Polymer structures were established by Fourier transform infrared and nuclear magnetic resonance spectroscopy. Morphology of the PUs was studied by differential scanning calorimetry and thermogravimetry. All PUs contain domains of crystalline and amorphous structures as indicated by X‐ray diffraction experiments. Furthermore, polymers were insoluble in the majority of organic solvents and, hence, their solution characterization was not possible. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2236–2244, 2005     

Segmented and nonsegmented polyurethanes: Polyaddition products of 4,4′‐bis(2‐hydroxyethoxy)diphenyl ether and 1,6‐hexanediisocyanate

New linear polyurethanes (PUs) derived from 4,4′‐bis(2‐hydroxyethoxy)diphenyl ether (4‐HEDE) and 1,6‐hexanediisocyanate (HDI) were synthesized by either melt or solution polymerization. We found that the properties of PUs obtained are dependent mainly on the kind of organic solvent, contribution of the catalyst, and concentration of the monomers used. Good results are obtained using aprotic solvent‐N,N‐dimethylformamide, ∼ 30 wt % concentration of monomers, dibutyltin dilaurate as a catalyst, and conducting the process at 90–100°C for 4 h. This article presents basic properties of the series of PUs obtained. Thermal properties of the polymers were investigated by means of thermal gravimetric analysis and differential scanning calorimetry. Molecular weight distribution was determined by gel permeation chromatography. Shore hardness and tensile test results are also presented. The structure of the resulting products was confirmed by elemental analysis, Fourier transform infrared spectroscopy and X‐ray diffractometry. We also present the properties of copolyurethanes type 4‐HEDE/HDI/1,6‐hexanediol or 4‐HEDE/HDI/polytetramethylene oxide containing variable amounts of 1,6‐hexanediol or polytetramethylene oxide (M _n ∼ 650) synthesized in the optimal conditions established earlier for PU 4‐HEDE/HDI. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 83–91, 1999     

Synthesis and characterization of polyhydroxylated polybutadiene binding 2,2′‐thiobis(4‐methyl‐6‐tert‐butylphenol) with isophorone diisocyanate

A macromolecular hindered phenol antioxidant, polyhydroxylated polybutadiene containing thioether binding 2,2′‐thiobis(4‐methyl‐6‐tert‐butylphenol) (PHPBT‐b‐TPH), was synthesized via a two‐step nucleophilic addition reaction using isophorone diisocyanate (IPDI) as linkage. First, the ? OH groups of PHPBT reacted with secondary ? NCO groups of IPDI to form the adduct PHPBT‐NCO, then the PHPBT‐b‐TPH was obtained by one phenolic ? OH of 2,2′‐thiobis(4‐methyl‐6‐tert‐butylphenol) (TPH) reacting with the PHPBT‐NCO. The PHPBT‐b‐TPH was characterized by Fourier transform infrared spectroscopy, ¹H nuclear magnetic resonance (¹H‐NMR), ¹³C‐NMR, and thermogravimetric analysis, and its antioxidant activity in natural rubber was studied by an accelerated aging test. Influences of reaction conditions on the two nucleophilic reactions between ? OH group and ? NCO group were investigated. In addition, catalytic mechanism for the reaction between PHPBT‐NCO and TPH was discussed. The results showed that the adduct PHPBT‐NCO could be obtained by using dibutyltin dilaurate (DBTDL) as catalyst, and the suitable temperature and DBTDL amount were 35°C and 3 wt %, respectively. However, triethylamine (TEA) was more efficient than DBTDL to catalyze the reaction between PHPBT‐NCO and TPH because of steric hindrance effect. In addition, it was found that the thermal stability and antioxidant activity of PHPBT‐b‐TPH were higher than those of the low molecular weight antioxidant TPH. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40942.     

Synthesis and characterization of 4,4′‐diaminodiphenyl methane‐based benzoxazines and their polymers

A series of diamine‐based benzoxazine precursors have been prepared using 4,4′‐diaminodiphenyl methane, formaldehyde, and different phenol derivatives including phenol, p‐cresol, and 2‐naphthol. Their chemical structures were identified by FTIR, ¹H NMR, and elemental analysis. The curing reactions of those precursors were monitored by FTIR and DSC. The obtained materials exhibited higher glass transition temperature and char yields than the corresponding bisphenol‐A based polybenzoxazines. The polybenzoxazine prepared from phenol showed the highest char yields of 65% and thermal stability with 5 and 10% weight‐loss temperatures at 346 and 432°C, respectively. The polybenzoxazine prepared from 2‐naphthol exhibited the highest glass transition temperature at 244°C. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Synthesis and characterization of organosoluble polyfluorinated polyimides derived from 3,3′,5,5′‐tetrafluoro‐4,4′‐diaminodiphenylmethane and various aromatic dianhydrides

A polyfluorinated aromatic diamine, 3,3′, 5,5′‐tetrafluoro‐4,4′‐diaminodiphenylmethane (TFDAM), was synthesized and characterized. A series of polyimides, PI‐1–PI‐4, were prepared by reacting the diamine with four aromatic dianhydrides via a one‐step high‐temperature polycondensation procedure. The obtained polyimide resin had moderate inherent viscosity (0.56–0.68 dL/g) and excellent solubility in common organic solvents. The polyimide films exhibited good thermal stability, with an initial thermal decomposition temperature of 555°C–621°C, a 10% weight loss temperature of 560°C–636°C, and a glass‐transition temperature of 280°C–326°C. Flexible and tough polyimide films showed good tensile properties, with tensile strength of 121–138 MPa, elongation at break of 9%–12%, and tensile modulus of 2.2–2.9 GPa. The polyimide films were good dielectric materials, and surface and volume resistance were on the order of a magnitude of 10¹⁴ and 10¹⁵ Ω cm, respectively. The dielectric constant of the films was below 3.0 at 1 MHz. The polyfluorinated films showed good transparency in the visible‐light region, with a cutoff wavelength as low as 302 nm and transmittance higher than 70% at 450 nm. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1442–1449, 2007     

Synthesis and characterization of high‐performance epoxy resin based on disiloxane and 4,4′‐oxybis(benzoic acid) ester

Epoxy‐terminated siloxane‐contained resin (BCDS/OBBA‐ETS) with high tensile strength and lap shear strength as well as good thermal stability was synthesized and characterized by ¹H‐NMR and Fourier transform infrared spectroscopy. Carboxy‐capped disiloxane‐4,4′‐oxybis (benzoic acid) ester oligomer (BCDS/OBBA) was firstly prepared from the reaction between 1,3‐bis(chloromethyl)‐1,1,3,3‐tetramethyl‐disiloxane and 4,4′‐oxybis(benzoic acid) (OBBA) in N,N‐dimethylformamide in the presence of triethylamine. Then, the BCDS/OBBA oligomer was reacted with epichlorohydrin to obtain the title BCDS/OBBA‐ETS resin. Cured with liquid polyamide L‐651, or diethylenetriamine, the mechanical and thermal properties as well as the lap shear strength of the BCDS/OBBA‐ETS resin were evaluated. The results indicated that the BCDS/OBBA‐ETS resin exhibited good thermal stability below 200°C, and the glass transition temperature (T_g) was about 64°C after cured with L‐651. The tensile strength of same cured BCDS/OBBA‐ETS resin was 27.46 MPa with a stain at break of 42.11%, and the lap shear strength for bonding stainless steel was 18.59 MPa. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis,characterization, and properties of low viscosity tetra‐functional epoxy resin N,N,N′,N′‐ tetraglycidyl‐3,3′‐diethyl‐4,4′‐diaminodiphenylmethane

Tetra‐functional epoxy resin N,N,N′,N′‐tetraglycidyl‐3,3′‐diethyl‐4,4′‐diaminodiphenylmethane (TGDEDDM) was synthesized and characterized. The viscosity of TGDEDDM at 25°C was 7.2 Pa·s, much lower than that of N,N,N′,N′‐tetraglycidyl‐4,4′‐diaminodiphenylmethane (TGDDM). DSC analysis revealed that the reactivity of TGDEDDM with curing agent 4,4′‐diamino diphenylsulfone (DDS) was significantly lower than that of TGDDM. Owing to its lower viscosity and reactivity, TGDEDDM/DDS exhibited a much wider processing temperature window compared to TGDDM/DDS. Trifluoroborane ethylamine complex (BF₃‐MEA) was used to promote the curing of TGDEDDM/DDS to achieve a full cure, and the thermal and mechanical properties of the cured TGDEDDM were investigated and compared with those of the cured TGDDM. It transpired that, due to the introduction of ethyl groups, the heat resistance and flexural strength were reduced, while the modulus was enhanced. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014 , 131, 40009.     

Synthesis of some new polymers by the polycondensation of 1,1‐bis(4‐chlorophenyl)‐2,2,2‐tricloroaethan with bisphenols and phase‐transfer catalysts

Two new polymers were synthesized by the polymerization of 1,1‐bis(4‐chlorophenyl)‐2,2,2‐trichloroaethan with 4,4‐isopropylidendiphenol (bisphenol A) and 4,4‐sulfonyl diphenol in a two‐phase system of water and dichloromethan in the presence of dibenzo‐24‐crown‐8. The polymers were characterized by IR and NMR spectroscopy. Thermogravimetric analysis of the aromatic bisphenol A polymer showed a 10% weight loss in air at 225°C. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 651–654, 2004     

Synthesis and characterization of new optically active poly(amide‐imide‐urethane) thermoplastic elastomers,derived from 4,4′‐(hexafluoroisopropylidene)‐N,N′‐bis(phthaloyl‐L‐leucine‐p‐aminobenzoic acid) and PEG‐MDI

A new class of optically active poly(amide‐imide‐urethane) was synthesized via two‐step reactions. In the first step, 4,4′‐methylene‐bis(4‐phenylisocyanate) (MDI) reacts with several poly(ethylene glycols) (PEGs) such as PEG‐400, PEG‐600, PEG‐2000, PEG‐4000, and PEG‐6000 to produce the soft segment parts. On the other hand, 4,4′‐(hexafluoroisopropylidene)‐N,N′‐bis(phthaloyl‐L ‐leucine‐p‐amidobenzoic acid) (2) was prepared from the reaction of 4,4′‐(hexafluoroisopropylidene)‐N,N′‐bis(phthaloyl‐L ‐leucine) diacid chloride with p‐aminobenzoic acid to produce hard segment part. The chain extension of the above soft segment with the amide‐imide 2 is the second step to give a homologue series of poly(amide‐imide‐urethanes). The resulting polymers with moderate inherent viscosity of 0.29–1.38 dL/g are optically active and thermally stable. All of the above polymers were fully characterized by IR spectroscopy, elemental analyses, and specific rotation. Some structural characterization and physical properties of this new optically active poly(amide‐imide‐urethanes) are reported. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2288–2294, 2004     

Synthesis and characterization of new soluble poly(ester‐imide)s containing noncoplanar 2,2′‐dimethyl‐4,4′‐biphenylene unit

A new diimide–diacid chloride (3) containing a noncoplanar 2,2′‐dimethyl‐4,4′‐biphenylene unit was synthesized by treating 2,2′‐dimethyl‐4,4′‐diamino‐biphenylene with trimellitic anhydride followed by refluxing with thionyl chloride. Various new poly(ester‐imide)s were prepared from 3 with different bisphenols by solution polycondensation in nitrobenzene using pyridine as hydrogen chloride quencher at 170°C. Inherent viscosities of the poly(ester‐imide)s were found to range between 0.31 and 0.35 dL g^?1. All of the poly(ester‐imide)s, except the one containing pendent adamantyl group 5e, exhibited excellent solubility in the following solvents: N,N‐dimethylformamide, tetrahydrofuran, tetrachloroethane, dimethyl sulfoxide, N,N‐dimethylacetamide, N‐methyl‐2‐pyrrolidinone, m‐cresol, o‐chlorophenol, and chloroform. The polymers showed glass‐transition temperatures between 166 and 226°C. The 10% weight loss temperatures of the poly(ester‐imide)s, measured by TGA, were found to be in the range between 415 and 456°C in nitrogen. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2486–2493, 2004     

Synthesis and characterization of new thermally stable poly(ester‐imide)s derived from 2,2′‐bis(4‐trimellitimidophenoxy)biphenyl and 2,2′‐bis(4‐trimellitimidophenoxy)‐1,1′‐binaphthyl and various aromatic dihydroxy compounds

A series of new alternating aromatic poly(ester‐imide)s were prepared by the polycondensation of the preformed imide ring‐containing diacids, 2,2′‐bis(4‐trimellitimidophenoxy)biphenyl (2a) and 2,2′‐bis(4‐trimellitimidophenoxy)‐1,1′‐binaphthyl (2b) with various aromatic dihydroxy compounds in the presence of pyridine and lithium chloride. A model compound (3) was also prepared by the reaction of 2b with phenol, its synthesis permitting an optimization of polymerization conditions. Poly(ester‐imides) were fully characterized by FTIR, UV‐vis and NMR spectroscopy. Both biphenylene‐ and binaphthylene‐based poly(ester‐imide)s exhibited excellent solubility in common organic solvents such as tetrahydrofuran, m‐cresol, pyridine and dichloromethane. However, binaphthylene‐based poly(ester‐imide)s were more soluble than those of biphenylene‐based polymers in highly polar organic solvents, including N‐methyl‐2‐pyrrolidone, N,N‐dimethylacetamide, N,N‐dimethylformamide and dimethyl sulfoxide. From differential scanning calorimetry thermograms, the polymers showed glass‐transition temperatures between 261 and 315 °C. Thermal behaviour of the polymers obtained was characterized by thermogravimetric analysis, and the 10 % weight loss temperatures of the poly(ester‐imide)s was in the range 449–491 °C in nitrogen. Furthermore, crystallinity of the polymers was estimated by means of wide‐angle X‐ray diffraction. The resultant poly(ester‐imide)s exhibited nearly an amorphous nature, except poly(ester‐imide)s derived from hydroquinone and 4,4′‐dihydroxybiphenyl. In general, polymers containing binaphthyl units showed higher thermal stability but lower crystallinity than polymers containing biphenyl units. Copyright © 2005 Society of Chemical Industry     

Synthesis and characterization of new poly(amide‐imide)s based on 1,4‐bis(trimellitimido)‐2,5‐dichlorobenzene

A series of new aromatic poly(amide‐imide)s were synthesized by the triphenyl phosphite‐activated polycondensation of the diimide‐diacid, 1,4‐bis(trimellitimido)‐2,5‐dichlorobenzene (I), with various aromatic diamines in a medium consisting of N‐methyl‐2‐pyrrolidone (NMP), pyridine, and calcium chloride. The poly(amide‐imide)s had inherent viscosities of 0.88–1.27 dL g⁻¹. The diimide‐diacid monomer (I) was prepared from 2,5‐dichloro‐p‐phenylenediamine with trimellitic anhydride. All the resulting polymers were amorphous and were readily soluble in a variety of organic solvents, including NMP and N,N‐dimethylacetamide. Transparent, flexible, and tough films of these polymers could be cast from N,N‐dimethylacetamide or NMP solutions. Cast films had tensile strengths ranging from 92 to 127 MPa, elongations at break from 4 to 24%, and initial moduli from 2.59 to 3.65 GPa. The glass transition temperatures of these polymers were in the range of 256°–317°C, and the 10% weight loss temperatures were above 430°C in nitrogen. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 271–278, 1999