首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
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  相似文献   

2.
A series of new aromatic poly(amide‐imide)s were synthesized by the triphenyl phosphite‐activated polycondensation of the diimide‐diacid, 2,5‐bis(trimellitimido)chlorobenzene (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 0.76–1.42 dL g−1. The diimide‐diacid monomer (I) was prepared from 2‐chloro‐p‐phenylenediamine with trimellitic anhydride. Most of the resulting polymers showed an amorphous nature 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. Their cast films had tensile strengths ranging from 74 to 95 MPa, elongations at break from 7 to 11%, and initial moduli from 1.38 to 3.25 GPa. The glass transition temperatures of these polymers were in the range of 233°–260°C, and the 10% weight loss temperatures were above 450°C in nitrogen. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1691–1701, 1999  相似文献   

3.
A new diimide–diacid monomer, N,N′‐bis(4‐carboxyphenyl)‐4,4′‐oxydiphthalimide (I), was prepared by azeotropic condensation of 4,4′‐oxydiphthalic anhydride (ODPA) and p‐aminobenzoic acid (p‐ABA) at a 1:2 molar ratio in a polar solvent mixed with toluene. A series of poly(amide–imide)s (PAI, IIIa–m) was synthesized from the diimide–diacid I (or I′, diacid chloride of I) and various aromatic diamines by direct polycondensation (or low temperature polycondensation) using triphenyl phosphite and pyridine as condensing agents. It was found that only IIIk–m having a meta‐structure at two terminals of the diamine could afford good quality, creasable films by solution‐casting; other PAIs III using diamine with para‐linkage at terminals were insoluble and crystalline; though IIIg–i contained the soluble group of the diamine moieties, their solvent‐cast films were brittle. In order to improve their to solubility and film quality, copoly(amide–imide)s (Co‐PAIs) based on I and mixtures of p‐ABA and aromatic diamines were synthesized. When on equimolar of p‐ABA (m = 1) was mixed, most of Co‐PAIs IV had improved solubility and high inherent viscosities in the range 0.9–1.5 dl g?1; however, their films were still brittle. With m = 3, series V was obtained, and all members exhibited high toughness. The solubility, film‐forming ability, crystallinity, and thermal properties of the resultant poly(amide–imide)s were investigated. © 2002 Society of Chemical Industry  相似文献   

4.
A series of new alternative poly(amide–imide)s (PAIs, IIIa–j ) was synthesized by the direct polycondensation of 1,4‐bis(4‐aminophenoxy)naphthalene (1,4‐BAPON) with various aromatic diimide–diacids. These polymers were obtained in quantitative yields with inherent viscosities of 0.71–1.03 dL/g. Except for IIIa, most of the polymers were soluble in aprotic polar solvents such as NMP, DMAc, DMF, and DMSO and could be solution‐cast into transparent, flexible, and tough films. The glass transition temperatures of these PAIs were in the range of 235–280°C. Thermogravimetric analyses established that these polymers were fairly stable up to 450°C, and 10% weight loss temperatures were recorded in the range of 520–569°C under nitrogen and 506–566°C under an air atmosphere. Compared with the PAIs with the 1,4‐bis(4‐aminophenoxy)benzene structure (series IV), the solubility of series III was better than that of series IV. Series III also exhibited lower crystallinity and better processability than those of series IV. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 217–225, 2000  相似文献   

5.
A new type of tetraimide‐dicarboxylic acid (I) was synthesized starting from the ring‐opening addition of m‐aminobenzoic acid (m‐ABA), 4,4′‐oxydiphthalic anhydride (ODPA) and 4,4′‐methylenedianiline (MDA) at a 2:2:1 molar ratio in N‐methyl‐2‐pyrrolidone (NMP), followed by cyclodehydration to the diacid I. A series of soluble and light‐coloured poly(amide–imide–imide)s (IIIa–j) was prepared by triphenyl phosphite‐activated polycondensation from the tetraimide‐diacid I with various aromatic diamines (IIa–j). All films cast from DMAc had cutoff wavelengths shorter than 400 nm (376–393 nm) and had b* values between 20.46 and 40.67; these polymers were much lighter in colour than those of the corresponding trimellitimide series. All polymers were readily soluble in a variety of organic solvents such as NMP, N,N‐dimethylacetamide, dimethyl sulfoxide, and even in the less polar m‐cresol and pyridine. Compared with those of corresponding ODPA–MDA polyimide, the solubilities of poly(amide–imide–imide)s IIIa–j were greatly improved. Polymers IIIa–j afforded tough, transparent, and flexible films, which had tensile strengths ranging from 82 to 105 MPa, elongations at break from 8 to 14%, and initial moduli from 2.0 to 2.2 GPa. The glass transition temperature of polymers were recorded at 255–288 °C. They had 10% weight loss at a temperature above 540 °C and left more than 60% residue even at 800 °C in nitrogen. © 2002 Society of Chemical Industry  相似文献   

6.
A new diacid containing optically active functional groups, N,N′‐(4,4′‐diphthaloyl)‐bis‐L ‐leucine diacid ( 3 ), was synthesized and used in a preparation of a series of poly(amide‐imide)s (PAIs) by direct polycondensation with various aromatic diamines in N‐methyl‐2‐pyrrolidinone (NMP). All polymers derived from diacid ( 3 ) were highly organosoluble in the solvents like N‐methyl‐2‐pyrrolidinone, N,N‐dimethylacetamide, N,N‐dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, γ‐butyrolactone, cyclohexanone, and chloroform at room temperature or upon heating. Inherent viscosities of the PAIs were found to range between 0.34 and 0.61·dL g?1. All the PAIs afforded flexible and tough films. The glass‐transition temperatures of these PAIs were recorded between 212 and 237°C by differential scanning calorimetry, and the 10% weight loss temperatures were ranging from 372 to 393°C and 336–372°C under nitrogen and air, respectively. The polyimide films had a tensile strength in the range of 63–88 MPa and a tensile modulus in the range of 1.2–1.7 GPa. Optically active PAIs exhibited specific rotations in the range of ?10.58° to ?38.70°. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007  相似文献   

7.
A new diamine 5,5′‐bis[4‐(4‐aminophenoxy)phenyl]‐hexahydro‐4,7‐methanoindan ( 3 ) was prepared through the nucleophilic displacement of 5,5′‐bis(4‐hydroxylphenyl)‐hexahydro‐4,7‐methanoindan ( 1 ) with p‐halonitrobenzene in the presence of K2CO3 in N,N‐dimethylformamide (DMF), followed by catalytic reduction with hydrazine and Pd/C in ethanol. A series of new polyamides were synthesized by the direct polycondensation of diamine 3 with various aromatic dicarboxylic acids. The polymers were obtained in quantitative yields with inherent viscosities of 0.76–1.02 dl g−1. All the polymers were soluble in aprotic dipolar solvents such as N,N‐dimethylacetamide (DMAc) and N‐methyl‐2‐pyrrolidone (NMP), and could be solution cast into transparent, flexible and tough films. The glass transition temperatures of the polyamides were in the range 245–282 °C; their 10% weight loss temperatures were above 468 °C in nitrogen and above 465 °C in air. © 2000 Society of Chemical Industry  相似文献   

8.
Three diimide‐diacids, 2,2‐bis[4‐(4‐trimellitimidophenoxy)phenyl]hexafluoropropane ( I‐A ), 2,2‐bis[4‐(4‐trimellitimidophenoxy)phenyl]propane ( I‐B ), and 5,5′‐bis[4‐ (4‐trimellitimidophenoxy)phenyl]hexahydro‐4,7‐methanoindan ( I‐C ), were prepared by the azeotropic condensation of trimellitic anhydride with three analogous diamines. Three series of alternating aromatic poly(arylate‐imide)s, having inherent viscosities of 0.41–0.82 dL/g, were synthesized from these diimide‐diacids ( I‐A , I‐B , and I‐C ) with various bisphenols by direct polycondensation using diphenyl chlorophosphate and pyridine as condensing agents. All of the polymers were readily soluble in a variety of organic solvents such as N‐methyl‐2‐pyrrolidone, N,N‐dimethylacetamide, and even in the less polar tetrahydrofuran. These polymers could be cast into transparent and tough films, which had strength at break values ranging from 73 to 98 MPa, elongation at break from 6 to 11%, and initial modulus from 1.6 to 2.2 GPa. The softening temperatures of the polymers were recorded at 145–248°C. They had 10% weight loss at a temperature above 450°C and left 35–51% residue even at 800°C in nitrogen. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3818–3825, 2003  相似文献   

9.
A series of new, organosoluble, and light‐colored poly(amide imide imide)s were synthesized from tetraimide dicarboxylic acid ( I ) and various aromatic diamines by direct polycondensation with triphenyl phosphite and pyridine as condensing agents. I was prepared by the azeotropic condensation of 4,4′‐(hexafluoroisopropylidene)diphthalic anhydride, m‐aminobenzoic acid, and 4,4′‐oxydianiline at a 2/2/1 molar ratio in N‐methyl‐2‐pyrrolidone (NMP)/toluene. The thin films cast from N,N‐dimethylacetamide (DMAc) had cutoff wavelengths shorter than 400 nm (365–394 nm) and color coordinate b* values between 13.10 and 36.07; these polymers were lighter in color than the analogous poly(amide imide)s and isomeric polymers. All of the polymers were readily soluble in a variety of organic solvents, including NMP, DMAc, N,N‐dimethylformamide, dimethyl sulfoxide, and even less polar dioxane and tetrahydrofuran. The cast films exhibited tensile strengths of 90–104 MPa, elongations at break of 7–22%, and initial moduli of 1.9–2.4 GPa. The glass‐transition temperatures of the polymers were recorded at 274–319°C. They had 10% weight losses at temperatures beyond 520°C and left more than a 50% residue even at 800°C in nitrogen. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 669–679, 2003  相似文献   

10.
A new monomer of tetraimide‐dicarboxylic acid (IV) was synthesized by starting from ring‐opening addition of 4,4′‐oxydiphthalic anhydride, trimellitic anhydride, and 1,4‐bis(4‐amino‐2‐trifluoromethylphenoxy)benzene at a 1:2:2 molar ratio in N‐methyl‐2‐pyrrolidone (NMP). From this new monomer, a series of novel organosoluble poly(amide‐imide‐imide)s with inherent viscosities of 0.7–0.96 dL/g were prepared by triphenyl phosphite activated polycondensation from the tetraimide‐diacid with various aromatic diamines. All synthesized polymers were readily soluble in a variety of organic solvents such as NMP and N,N‐dimethylacetamide, and most of them were soluble even in less polar m‐cresol and pyridine. These polymers afforded tough, transparent, and flexible films with tensile strengths ranging from 99 to 125 MPa, elongations at break from 12 to 19%, and initial moduli from 1.6 to 2.4 GPa. The thermal properties and stability were also good with glass‐transition temperatures of 236–276°C and thermogravimetric analysis 10 wt % loss temperatures of 504–559°C in nitrogen and 499–544°C in air. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2854–2864, 2006  相似文献   

11.
N‐Trimellitylimido‐L ‐leucine was reacted with thionyl chloride, and N‐trimellitylimido‐L ‐leucine diacid chloride was obtained in a quantitative yield. The reaction of this diacid chloride with p‐aminobenzoic acid was performed in dry tetrahydrofuran, and bis(p‐amidobenzoic acid)‐N‐trimellitylimido‐L ‐leucine (5) was obtained as a novel optically active aromatic imide–amide diacid monomer in a high yield. The direct polycondensation reaction of the monomer imide–amide diacid 5 with 4,4′‐diaminodiphenylsulfone, 4,4′‐diaminodiphenylether, 1,4‐phenylenediamine, 1,3‐phenylenediamine, 2,4‐diaminotoluene, and benzidine (4,4′‐diaminobiphenyl) was carried out in a medium consisting of triphenyl phosphite, N‐methyl‐2‐pyrolidone, pyridine, and calcium chloride. The resulting novel poly(amide imide)s (PAIs), with inherent viscosities of 0.22–0.52 dL g?1, were obtained in high yields, were optically active, and had moderate thermal stability. All of the compounds were fully characterized with IR spectroscopy, elemental analyses, and specific rotation. Some structural characterization and physical properties of these new optically active PAIs are reported. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 35–43, 2002; DOI 10.1002/app.10181  相似文献   

12.
Eight new flame‐retardant poly(amide‐imide)s with high inherent viscosities containing phosphine oxide moieties in main chain were synthesized from the polycondensation reaction of N,N′‐(3,3′‐diphenylphenylphosphine oxide) bistrimellitimide diacid chloride 7, with eight ;aromatic diamine 8a–h by two different methods such as solution and microwave‐assisted polycondensation. Results showed that the microwave‐assisted polycondensation by using a domestic microwave oven proceeded rapidly, compared with solution polycondensation and were completed within about 10–12 min. The resulting poly(amide‐imide)s 9a–h showed high thermal stability and flame‐retardant properties. All of the obtained polymers were fully characterized by means of elemental analysis, viscosity measurements, solubility test, and FTIR spectroscopy. Thermal properties of the PAIs 9a–h were investigated by using thermal gravimetric analysis (TGA), derivative thermogravimetric analysis (DTG), and differential scanning calorimetry (DSC). Char yield measurements at 600°C demonstrated that incorporating phosphine oxide moieties in polymer backbone markedly improves their flame retardancy. All of the earlier polymers were soluble at room temperature in various organic solvents such as NMP, DMF, DMSO, DMAc, and concentrated sulfuric acid. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4263–4269, 2006  相似文献   

13.
An imide ring‐performed dicarboxylic acid bearing one hexafluoroisopropylidene and two ether linkages between aromatic rings, 2,2‐bis[4‐(4‐trimellitimidophenoxy)phenyl]hexafluoropropane (II), was prepared from the condensation of 2,2‐bis[4‐(4‐aminophenoxy)phenyl]hexafluoropropane and trimellitic anhydride. A novel series of poly(amide‐imide)s having inherent viscosities of 0.72 ∼ 1.86 dL g−1 was prepared by the triphenyl phosphite‐activated polycondensation from the diimide‐diacid (II) with various aromatic diamines in a medium consisting of N‐methyl‐2‐pyrolidone, pyridine, and calcium chloride. Several of the resulting polymers were soluble in polar amide solvents, and their solutions could be cast into transparent, thin, flexible films having good tensile properties and high thermal stability. The 10% weight loss temperatures were all above 495°C in air or nitrogen atmosphere, and the glass transition temperatures were in the range of 237°–276°C. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 823–831, 1999  相似文献   

14.
A series of fluorinated polyamideimides (PAIs) were synthesized by the direct polycondensation of a novel diimide‐diacid, 1,4‐bis(trimellitimido‐2‐trifluoromethylphenoxy) benzene (BTTFB), with aromatic diamines by using triphenyl phosphite (TPP) and pyridine as condensation agents in a medium consisting of N‐methyl‐2‐pyrrolidone (NMP) and CaCl2. Most of the resulting polymers showed an amorphous nature. All the fluorinated PAIs were readily soluble in a variety of organic solvents such as NMP, N,N‐dimethyl acetamide, dimethylformamide, and dimethyl sulfoxide and could even be dissolved in less polar solvents such as THF and m‐cresol. The PAIs had inherent viscosities of 0.77–0.93 dL/g, depending on the diamines. All the soluble PAIs afforded transparent, flexible, and tough films that exhibited excellent thermal stability, good mechanical properties, and low moisture absorption. The glass transition temperatures of these PAIs ranged from 244 to 272°C and the 5% weight loss temperatures were >525°C in nitrogen. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 321–327, 2005  相似文献   

15.
A CF3‐containing diamine, 4,4′‐bis(4‐amino‐2‐trifluoromethylphenoxy)benzophenone ( 2 ), was synthesized from 4,4′‐dihydroxybenzophenone and 2‐chloro‐5‐nitrobenzotrifluoride. Imide‐containing diacids ( 3 and 5Ba – 5Bg ) were prepared by the condensation reaction of aromatic diamines and trimellitic anhydride. Then, two series of novel soluble aromatic poly(amide imide)s (PAIs; 6Aa – 6Ak and 6Ba – 6Bg ) were synthesized from a diamine ( 4Aa – 4Ak or 2 ) with the imide‐containing diacids ( 3 and 5Ba – 5Bg ) via direct polycondensation with triphenyl phosphate and pyridine. The aromatic PAIs had inherent viscosities of 0.74–1.76 dL/g. All of the synthesized polymers showed excellent solubility in amide‐type solvents, such as N‐methyl‐2‐pyrrolidone and N,N‐dimethylacetamide (DMAc), and afforded transparent and tough films by DMAc solvent casting. These polymer films had tensile strengths of 90–113 MPa, elongations at break of 8–15%, and initial moduli of 2.0–2.9 GPa. The glass‐transition temperatures of the aromatic PAIs were in the range 242–279°C. They had 10% weight losses at temperatures above 500°C and showed excellent thermal stabilities. The 6B series exhibited less coloring and showed lower yellowness index values than the corresponding 6A series. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:3641–3653, 2006  相似文献   

16.
Novel aromatic poly(amide imide)s (m‐PAIs, m = 8, 12, 16) containing preformed isophthalamide unit and pendent n‐alkyloxy (‐O‐n‐CmH2m+1, m = 8, 12, 16) side chains were prepared in thin films by polymerization of pyromellitic dianhydride (PMDA) with N,N′‐bis(4‐aminophenyl)‐5‐(n‐alkyloxy)isophthalamides (m‐DAs) obtained from N,N′‐bis(4‐nitrophenyl)‐5‐(n‐alkyloxy)isophthalamides (m‐DNs). The m‐PAI films were tough, flexible and transparent with inherent viscosities in the 1.25–1.67 dL/g range in DMAc and soluble in DMAc and NMP on heating. In TGA m‐PAIs began to degrade around 440°C and in DSC no phase transitions were detected. In X‐ray diffractometry the m‐PAIs appeared amorphous with loosely developed layered crystalline structure. In liquid crystal (LC)‐aligning performance measured using 4‐n‐pentyl‐4′‐cyanobiphenyl (5CB) on thin film surfaces rubbed with standard velvet fibers, the m‐PAIs showed homogeneous LC alignment parallel to the rubbing direction with 2.5–17.5° pretilt angles, depending on the rubbing density and n‐alkyloxy side chain length. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007  相似文献   

17.
New fluorinated poly(imide‐amide)s have been synthesized by solution polycondensation of various aromatic diamines containing a naphthalene unit with diacid chlorides having both imide and hexafluoroisopropylidene (6F) groups. These polymers are soluble in polar aprotic solvents, such as N‐methylpyrrolidone (NMP) or N,N‐dimethylformamide (DMF), and can be cast into flexible thin films from solutions. They show high thermooxidative stability with decomposition temperatures being above 425°C and glass transition temperatures being in the range of 235–305°C. The polymer films exhibit a low dielectric constant and tough mechanical properties.  相似文献   

18.
A dicarboxylic acid ( 1 ) bearing two phthalimide rings was prepared by the condensation of N-phenyl-3,3-bis[4-(4-aminophenoxy)phenyl]phthalimidine and trimellitic anhydride. A new family of poly(amide–imide)s having inherent viscosities of 0.65–1.65 dl/g was prepared by the triphenyl phosphite activated polycondensation of the diimide–diacid 1 with various aromatic diamines in a medium consisting of N-methyl-2-pyrrolidone (NMP), pyridine, and calcium chloride. All the resulting polymers showed an amorphous nature and were readily soluble in polar solvents such as NMP and N,N-dimethylacetamide. The soluble poly(amide–imide)s afforded transparent, flexible, and tough films. The glass transition temperatures of these polymers were in the range 249–340°C and the 10% weight loss temperatures were above 545°C in nitrogen.  相似文献   

19.
The reaction of 4‐(3‐hydroxynaphthalene)‐1,2,4‐triazolidine‐3,5‐dione ( 3HNTD ) with n‐propylisocyanate was performed at different molar ratios. The resulting monosubstituted urea and disubstituted urea‐urethane derivatives were obtained in high yields and were used as model compounds for polymerization reactions. 3HNTD as a monomer was used in the preparation of heterocyclic poly(urea‐urethane)s to produce photoactive polymers, by polycondensation with different diisocyanates in N,N‐dimethylacetamide (DMAc) solution. Chromophoric heterocyclic polymers containing naphthalene group, obtained in quantitative yields, possessed inherent viscosities in the range of 0.14–0.38 dL/g. The resulting poly(urea‐urethane)s is insoluble in most organic solvents, but easily soluble in polar solvents such as dimethyl sulfoxide (DMSO), DMAc, and N‐methylpyrrolidone (NMP). The polymers were characterized by IR, 1H‐NMR, elemental analysis, and TGA. Fluorimetric and UV–vis studies of the monomer as well as polymers were performed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008  相似文献   

20.
A series of novel benzhydrol-containing poly(amide-imide)s (PAIs) have been prepared from a new diimide-dicarboxylic acid, N,N′-bis(4-hydroxycarbonyl)-benzhydrol-3,3′,4,4′-tetracarboxydiimide (BHTDA-DIA), with various diamines by direct polycondensation using triphenyl phosphite and pyridine as condensing agents. The polymers obtained had inherent viscosities of 0.35–0.96 dl g−1. All these PAIs, except polymer PAI-2, were soluble in N-methyl-2-pyrrolidinone and N,N-dimethylacetamide containing LiCl (1 wt%). Tough and flexible PAI films could be obtained by casting PAIs from their DMAc or NMP solutions, except for polymer PAI-2. The polymer films had a tensile strength of 93–111 MPa, an elongation at break range of 4–6%, and an initial modulus range of 2.7–3.8 GPa. The glass transition temperatures of most polymers were found to be above 255 °C. These polymers were fairly stable up to a temperature around or above 400 °C, and lost 10% weight in the range 426–507 °C in nitrogen and 423–515 °C in air. © 1999 Society of Chemical Industry  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号