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1.
4,4′‐(Hexafluoroisopropylidene)‐bis‐(phthalic anhydride) (1) was reacted with L ‐leucine (2) in toluene solution at refluxing temperature in the presence of triethylamine and the resulting imide‐acid (4) was obtained in quantitative yield. The compound (4) was converted to the diacid chloride (5) by reaction with thionyl chloride. The polymerization reaction of the imide‐acid chloride (5) with 1,6‐hexamethylenediamine (6a) , benzidine (6b) , 4,4′‐diaminodiphenylmethane (6c) , 1,5‐diaminoanthraquinone (6d) , 4,4′‐sulfonyldianiline (6e) , 3,3′‐diaminobenzophenone (6f) , p‐phenylenediamine (6g) and 2,6‐diaminopyridine (6h) was carried out in chloroform/DMAc solution. The resulting poly(amide‐imide)s were obtained in high yield and are optically active and thermally stable. All of the above compounds were fully characterized by IR, elemental analyses and specific rotation. Some structural characterization and physical properties of those optically active poly(amide‐imide)s are reported. © 1999 Society of Chemical Industry  相似文献   

2.
A new simple and rapid polycondensation reaction of 4,4′‐carbonyl‐bis(phthaloyl‐L ‐alanine)diacid chloride [N,N ′‐(4,4′‐carbonyldiphthaloyl)]bisalanine diacid chloride with several diphenols, such as bisphenol‐A, phenolphthalein, 1,8‐dihydroxyanthraquinone, 4,4′‐dihydroxybiphenyl, 1,5‐dihydroxynaphthalene and hydroquinone, in the presence of a small amount of a polar organic medium such as o‐cresol was performed using a domestic microwave oven. The polycondensation reaction proceeded rapidly and was almost complete within 12 min to give a series of poly(ester‐imide)s with inherent viscosities of about 0.35–0.58 dl g−1. The resulting poly(ester‐imide)s were obtained in high yield and are optically active and thermally stable. All the above compounds have been fully characterized by IR spectroscopy, elemental analysis, inherent viscosity (ηinh), solubility test and specific rotation. Thermal properties of the poly(ester‐imide)s have been investigated using thermal gravimetric analysis (TGA). © 2000 Society of Chemical Industry  相似文献   

3.
A new class of optically active poly(amide–imide–urethane)s (PAIUs) was synthesized via a two‐step diisocyanate route under microwave irradiation. In these reactions, 4,4′‐methylene‐bis(4‐phenylisocyanate) was reacted with bis(p‐amido benzoic acid)‐N‐trimellitylimido‐L ‐leucine and poly(ethylene glycol diol)s (PEGs), such as PEG‐400, PEG‐600, PEG‐1000, and PEG‐2000, to furnish a series of new PAIUs. The effects of different reaction conditions, such as the method of preparation (polyol or acid chain extension), the prepolymerization step (NCO‐terminated oligoamide or NCO‐terminated polyether polyol), the irradiation time and power, the reaction solvent, the soft‐segment length, and the presence or absence of reaction catalysts (e.g., triethylamine, pyridine, and dibutyltin dilaurate), on the properties of the copolymers, including the solubility, viscosity, and thermal behavior, were investigated. The resulting multiblock copolymers had inherent viscosities of 0.15–0.53 dL/g. These multiblock copolymers were optically active, thermally stable, and soluble in amide‐type solvents. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1781–1792, 2005  相似文献   

4.
Rapid and highly efficient synthesis of novel poly(amide‐imide)s (PAIs) were achieved under microwave irradiation by using a domestic microwave oven from the polycondensation reactions of 4,4′‐carbonyl‐bis(phthaloyl‐L ‐alanine) diacid chloride [N,N′‐(4,4′‐carbonyldiphthaloyl)] bisalanine diacid chloride (1) with six different derivatives of tetrahydropyrimidinone and tetrahydro‐2‐thioxopyrimidine compounds (2a–2f) in the presence of a small amount of a nonpolar organic medium that acts as a primary microwave absorber. Suitable organic media was o‐cresol. The polycondensation proceeded rapidly and was almost completed within 10 min, giving a series of PAIs with inherent viscosities of about 0.25–0.45 dL/g. The resulting PAIs were obtained in high yield and are optically active and thermally stable. All of the above compounds were fully characterized by means of Fourier transform infrared spectroscopy, elemental analyses, inherent viscosity (ηinh), solubility test, and specific rotation. Thermal properties of the PAIs were investigated using thermogravimetric analysis. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2416–2421, 2001  相似文献   

5.
2,5‐Dibromo‐1,4‐(dihydroxymethyl)benzene was used as initiator in ring‐opening polymerization of ε‐caprolactone in the presence of stannous octoate (Sn(Oct)2) catalyst. The resulting poly(ε‐caprolactone) (PCL) macromonomer, with a central 2,5‐dibromo‐1,4‐diphenylene group, was used in combination with 1,4‐dibromo‐2,5‐dimethylbenzene for a Suzuki coupling in the presence of Pd(PPh3)4 as catalyst or using the system NiCl2/bpy/PPh3/Zn for a Yamamoto‐type polymerization. The poly(p‐phenylenes) (PPP) obtained, with PCL side chains, have solubility properties similar to those of the starting macromonomer, ie soluble in common organic solvents at room temperature. The new polymers were characterized by 1H and 13C NMR and UV spectroscopy and also by GPC measurements. The thermal behaviour of the precursor PCL macromonomer and the final poly(p‐phenylene)‐graft‐poly(ε‐caprolactone) copolymers were investigated by thermogravimetric analysis and differential scanning calorimetry analyses and compared. Copyright © 2004 Society of Chemical Industry  相似文献   

6.
Pyromellitic dianhydride (benzene‐1,2,4,5‐tetracarboxylic dianhydride) (1) was reacted with L‐phenylalanine (2) in a mixture of acetic acid and pyridine (3 : 2) and the resulting imide‐acid [N,N′‐(pyromellitoyl)‐bis‐L‐phenylalanine diacid] (4) was obtained in quantitative yield. The compound (4) was converted to the N,N′‐(pyromellitoyl)‐bis‐L‐phenylalanine diacid chloride (5) by reaction with thionyl chloride. A new facile and rapid polycondensation reaction of this diacid chloride (5) with several aromatic diols such as phenol phthalein (6a), bisphenol‐A (6b), 4,4′‐hydroquinone (6c), 1,8‐dihydroxyanthraquinone (6d), 4,4‐dihydroxy biphenyl (6e), and 2,4‐dihydroxyacetophenone (6f) was developed by using a domestic microwave oven in the presence of a small amount of a polar organic medium such as o‐cresol. The polymerization reactions proceeded rapidly and are completed within 20 min, producing a series of optically active poly(ester‐imide)s with good yield and moderate inherent viscosity of 0.10–0.26 dL/g. All of the above polymers were fully characterized by IR, elemental analyses, and specific rotation. Some structural characterization and physical properties of these optically active poly(ester‐imide)s are reported. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2211–2216, 2002  相似文献   

7.
A series of poly(ether–ester) copolymers were synthesized from poly(2,6 dimethyl‐1,4‐phenylene oxide) (PPO) and poly(ethylene terephthalate) (PET). The synthesis was carried out by two‐step solution polymerization process. PET oligomers were synthesized via glycolysis and subsequently used in the copolymerization reaction. FTIR spectroscopy analysis shows the coexistence of spectral contributions of PPO and PET on the spectra of their ether–ester copolymers. The composition of the poly(ether–ester)s was calculated via 1H NMR spectroscopy. A single glass transition temperature was detected for all synthesized poly(ether–ester)s. Tg behavior as a function of poly(ether–ester) composition is well represented by the Gordon‐Taylor equation. The molar masses of the copolymers synthesized were calculated by viscosimetry. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006  相似文献   

8.
Pyromellitic dianhydride (1,2,4,5‐benzenetetracarboxylic acid 1,2,4,5‐dianhydide) was reacted with L ‐valine in a mixture of acetic acid and pyridine (3:2) at room temperature, and then was refluxed at 90–100 °C, N,N′‐(pyromellitoyl)‐bis‐L ‐valine diacid was obtained in quantitative yield. The imide–acid was converted to N,N′‐(pyromellitoyl)‐bis‐L ‐valine diacid chloride by reaction with thionyl chloride. Rapid and highly efficient synthesis of a number of poly(amide–imide)s was achieved under microwave irradiation using a domestic microwave oven by polycondensation of N,N′‐(pyromellitoyl)‐bis‐L ‐valine diacid chloride with six different derivatives of 5,5‐disubstituted hydantoin compounds in the presence of a small amount of a polar organic medium that acts as a primary microwave absorber. A suitable organic medium was o‐cresol. The polycondensation proceeded rapidly, compared with conventional melt polycondensation and solution polycondensation and was almost completed within 8 min, giving a series of poly(amide–imide)s with inherent viscosities in the range 0.15–0.36 dl g?1. The resulting poly(amide–imide)s were obtained in high yield and are optically active and thermally stable. All of the above compounds were fully characterized by Fourier‐transform infrared (FT‐IR) spectroscopy, elemental analysis, inherent viscosity (ηinh) measurements, solubility testing and specific rotation measurements. The thermal properties of the poly(amide–imide)s were investigated by using thermogravimetric analysis. Copyright © 2004 Society of Chemical Industry  相似文献   

9.
4,4′‐Hexafluoroisopropylidene‐2,2‐bis(phthalic acid anhydride) (1) was treated with L ‐methionine (2) in acetic acid and the resulting 4,4′‐(hexafluoroisopropylidene)‐N,N′‐bis(phthaloyl‐L ‐methionine) diacid (4) was obtained in high yields. The direct polycondensation reaction of this diacid with several aromatic diols, such as bisphenol A (5a), phenolphthalein (5b), 1,4‐dihydroxybenzene (5c), 4,4′‐dihydroxydiphenyl sulfide (5 d), 4,6‐dihydroxypyrimidine (5e), 4,4′‐dihydroxydiphenyl sulfone (5f), and 2,4′‐dihydroxyacetophenone (5g), was carried out in a system of tosyl chloride (TsCl), pyridine (Py), and N,N‐dimethylformamide (DMF). The reactions with TsCl were significantly promoted by controlling alcoholysis with diols, in the presence of catalytic amounts of DMF, to give a series of optically active poly(ester imide)s, (PEI)s, with good yield and moderate inherent viscosity ranging from 0.43 to 0.67 dL/g. The polycondensation reactions were significantly affected by the amounts of DMF, molar concentration of monomers, TsCl and Py, aging time, temperature, and reaction time. All of the aforementioned polymers were fully characterized by 1H NMR, FTIR, elemental analysis, and specific rotation. Some structural characterization and physical properties of these optically active PEIs are reported. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 455–460, 2006  相似文献   

10.
Optically active poly(L ‐phenyllactic acid) (Ph‐PLLA), poly(L ‐lactic acid) (PLLA), and poly(L ‐phenyllactic acid‐co‐L ‐lactic acid) with weight‐average molecular weight exceeding 6 × 103 g mol?1 were successfully synthesized by acid catalyzed direct polycondensation of L ‐phenyllactic acid and/or L ‐lactic acid in the presence of 2.5–10 wt % of p‐toluenesulfonic acid. Their physical properties and crystallization behavior were investigated by differential scanning calorimetry, thermogravimetry, and polarimetry. The absolute value of specific optical rotation ([α]) for Ph‐PLLA (?38 deg dm?1 g?1 cm3) was much lower than that of [α] for PLLA (?150 deg dm?1 g?1 cm3), suggesting that the helical nature was reduced by incorporation of bulky phenyl group. PLLA was crystallizable during solvent evaporation, heating from room temperature, and cooling from the melt. Incorporation of a very low content of bulky phenyllactyl units even at 4 mol % suppressed the crystallization of L ‐lactyl unit sequences during heating and cooling, though the copolymers were crystallizable for L ‐phenylactyl units up to 6 mol % during solvent evaporation. The activation energy of thermal degradation (ΔEtd) for Ph‐PLLA (200 kJ mol?1) was higher than that for PLLA (158 kJ mol?1). The ΔEtd for the copolymers increased with an increase in L ‐phenyllactyl unit content. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008  相似文献   

11.
Novel bioactive and optically active poly(N‐acryloyl‐L ‐phenylalanine) (PAPA) was synthesized by atom transfer radical polymerization. PAPA‐silver (Ag) nanocomposites have been successfully prepared via in situ reducing Ag+ ions anchored in the polymer chain using hydrazine hydrate as reducing agent in an aqueous medium. By controlling of the amount of Ag+ ions introduced, we have produced an organic/inorganic nanocomposite containing Ag nanoparticles with well controlled size. Nanocomposites were characterized by X‐ray diffraction (XRD), UV–Vis spectrophotometry, transmission electron microscopy, and Fourier transform infrared. XRD pattern showed presence of Ag nanoparticles. The PAPA/Ag nanocomposites with 1 : 10 silver nitrate (AgNO3) : PAPA ratio revealed the presence of well‐dispersed Ag nanoparticles in the polymer matrix. All of these Ag nanoparticles formed are spherical and more than 80% of them are in the range of 15–25 nm. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011  相似文献   

12.
13.
Pyromellitic dianhydride (benzene‐1,2,4,5‐tetracarboxylic dianhydride) (1) was reacted with several amino acids in acetic acid and the resulting imide‐acid [N,N′‐(pyromellitoyl)‐bis‐L ‐amino acid diacid] (4a–4d) was obtained in high yield. The direct polycondensation reaction of these diacids with 4,4′‐thiobis(2‐tert‐butyl‐5‐methylphenol) (5) was carried out in a system of tosyl chloride(TsCl), pyridine, and N,N‐dimethyl formamide (DMF) to give a series of novel optically active poly(esterimide)s. Step‐growth polymerization was carried out by varying the time of heating and the molar ratio of TsCl/diacid, and the optimum conditions were achieved. These new chiral polymers were characterized with respect to chemical structure and purity by means of specific rotation experiments, FTIR, 1H‐NMR, X‐ray diffraction, elemental, and thermogravimetric analysis (TGA) field emission scanning electron microscopy (FE‐SEM) techniques. These polymers are readily soluble in many polar organic solvents like DMF, N,N‐dimethyl acetamide, dimethyl sulfoxide, N‐methyl‐2‐pyrrolidone, and protic solvents such as sulfuric acid. TGA showed that the 10% weight loss temperature in a nitrogen atmosphere was more than 390°C; therefore, these new chiral polymers have useful levels of thermal stability associated with good solubility. Furthermore, study of the surface morphology of the obtained polymers by FE‐SEM showed that each polymers exhibit nanostructure morphology. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011  相似文献   

14.
The effect of ultrasonication on the dehydrogenation of poly(1,3‐cyclohexadiene) (PCHD) with benzoquinones was examined with the aim of improving the rate of reaction at moderate temperature. The type of solvent and the ultrasound treatment strongly affected the dehydrogenation of PCHD. The rate of reaction of the dehydrogenation of PCHD with 2,3‐dichloro‐5, 6‐dicyano‐1,4‐benzoquinone (DDQ) or 3,4,5,6‐tetrachloro‐1,2‐(o)‐benzoquinone (TOQ) was markedly improved by the use of ultrasound, and poly(para‐phenylene) (PPP) and PPP–TOQ complex, respectively, were successfully obtained. The electron drift mobility for PPP was of the order of 10?4 cm2 V?1 s?1 with a negative slope, while that for PPP–TOQ complex was of the order of 10?3 to 10?4 cm2 V?1 s?1 with a negative slope. The dehydrogenation of PCHD with benzoquinones under ultrasonication is thus an effective method to obtain soluble PPP with a well‐defined polymer chain structure. Copyright © 2010 Society of Chemical Industry  相似文献   

15.
The objective of this study was to prepare high molecular weight poly(ester‐anhydride)s by melt polycondensation. The polymerization procedure consisted of the preparation of carboxylic acid terminated poly(?‐caprolactone) prepolymers that were melt polymerized to poly(?‐caprolactone)s containing anhydride functions along the polymer backbone. Poly(?‐caprolactone) prepolymers were prepared using either 1,4‐butanediol or 4‐(hydroxymethyl)benzoic acid as initiators, yielding hydroxyl‐terminated intermediates that were then converted to carboxylic acid‐terminated prepolymers by reaction with succinic anhydride. Prepolymers were then allowed to react with an excess of acetic anhydride, followed by subsequent polycondensation to resulting high molecular weight poly(ester‐anhydride)s. Upon coupling of prepolymers, size exclusion chromatography analyses showed an increase from 3600 to 70,000 g/mol in number‐average molecular weight (Mn) for the 1,4‐butanediol initiated polymer, and an increase from 7200 to 68,000 g/mol for the 4‐(hydroxymethyl)benzoic acid‐initiated polymer. 4‐Hydroxybenzoic acid and adipic acid were also used as initiators in the preparation of poly(?‐caprolactone) prepolymers. However, with these initiators, the results were not satisfactory. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 176–185, 2001  相似文献   

16.
The miscibility behavior of poly(vinyl phenyl ketone hydrogenated) (PVPhKH) and poly(2,6‐dimethyl‐1,4‐phenylene oxide) (PPO) are studied by differential scanning calorimetry, thermomechanical analysis, and FTIR spectroscopy. Two miscibility windows between 10 to 40 and 60 to 90 wt % PPO are detected. Only the blend with 50 wt % PPO is immiscible. The best fit of the Gordon–Taylor equation of the experimental glass‐transition temperatures for miscible PVPhKH/PPO blends is shown. A study by FTIR spectroscopy suggests that hydrogen bonding interactions are formed between the hydroxyl groups of PVPhKH and the ether groups of PPO. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1887–1892, 2004  相似文献   

17.
Poly(2,6‐dimethyl‐1,4‐phenylene oxide) (PPO) is a chemically resistant polymer and, therefore, an attractive material for the formation of membranes. However, membranes of unmodified PPO prepared by an immersion precipitation possess very low hydraulic permeabilities at the filtration processes. The membranes with higher hydraulic permeabilities can be prepared from sulfonated PPO and/or from blends of unsulfonated PPO and sulfonated PPO. In conclusion, the mechanism of the formation of membranes from blends of unsulfonated PPO and sulfonated PPO is suggested. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 161–167, 1999  相似文献   

18.
A pyromellitic dianhydride (benzene‐1,2,4,5‐tetracarboxylic dianhydride) was reacted with L ‐isoleucine in acetic acid, and the resulting imide acid [N,N′‐(pyromellitoyl)‐bis‐L ‐isoleucine] (4) was obtained in a high yield. 4 was converted into N,N′‐(pyromellitoyl)‐bis‐L ‐isoleucine diacid chloride by a reaction with thionyl chloride. The polycondensation reaction of this diacid chloride with several aromatic diamines, including 1,4‐phenylenediamine, 4,4′‐diaminodiphenyl methane, 4,4′‐diaminodiphenylsulfone (4,4′‐sulfonyldianiline), 4,4′‐diaminodiphenylether, 2,4‐diaminotoluene, and 1,3‐phenylenediamine, was developed with two methods. The first method was polymerization under microwave irradiation, and the second method was low‐temperature solution polymerization, with trimethylsilyl chloride used as an activating agent for the diamines. The polymerization reactions proceeded quickly and produced a series of optically active poly(amide imide)s with good yields and moderate inherent viscosities of 0.17–0.25 dL/g. All of the aforementioned polymers were fully characterized by IR, elemental analyses, and specific rotation. Some structural characterization and physical properties of these optically active poly(amide imide)s are reported. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 951–959, 2004  相似文献   

19.
Aromatic poly(amide‐imide)s (PAIs) are high‐performance materials with a good compromise between thermal stability and processability when compared with polyamides or polyimides of analogous structures. In addition, the incorporation of photosensitive functional groups and chiral segments into the polymer backbone can lead to interesting polymers for various applications. In this work, six new photosensitive and chiral PAIs were synthesized from the direct polycondensation reaction of novel N,N′‐(bicyclo[2,2,2]oct‐7‐ene‐tetracarboxylic)‐bis‐L ‐amino acids with 2,5‐bis(4‐aminobenzylidene)cyclopentanone as dibenzalacetone moiety using two different methods. The polymerization reactions produced a series of photosensitive and optically active PAIs in high yields and with good inherent viscosities. The resulting polymers were characterized using Fourier transform infrared and 1H NMR spectroscopy, elemental analysis, inherent viscosity, specific rotation, solubility tests and UV‐visible spectroscopy. The thermal properties of the PAIs were investigated using thermogravimetric analysis. Due to the presence of the dibenzalacetone moiety in the polymer chain, the PAIs have photosensitive properties. Also, these PAIs are optically active and soluble in various organic solvents. These resulting new polymers have the potential to be used in column chromatography for the separation of enantiomeric mixtures. Copyright © 2009 Society of Chemical Industry  相似文献   

20.
Two N‐phenylmaleimide derivatives bearing a chiral oxazoline group, N‐[o‐(4‐phenyl‐4,5‐dihydro‐1,3‐oxazol‐2‐yl)phenyl]maleimide [(R)‐PhOPMI] and N‐[o‐(4‐isopropyl‐4,5‐dihydro‐1,3‐oxazol‐2‐yl)phenyl]maleimide [(S)‐PriOPMI], were polymerized using in situ generated calixarene‐based phenates as initiators to yield optically active polymers. The formation of star‐shaped architectures was strongly dependent on both polymerization conditions and calixarene moieties. In the case of polymerization conducted in toluene at 80–100 °C, the arm‐chain numbers achieved their respective maxima for the polymers with these multifunctional initiators. In contrast, the polymers obtained in polymerizations at lower temperature possessed fewer arm chains. The structure and chiroptical properties were investigated on the basis of 13C NMR, multiangular laser light scattering, gel permeation chromatography, and circular dichroism for the macromolecules with calixarene cores. Copyright © 2006 Society of Chemical Industry  相似文献   

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