基于间苯二甲胺单体的聚酰亚胺的合成与性能

以间苯二甲胺（MXDA）为二胺单体分别与五种芳香族二酐：4,4''-氧双邻苯二甲酸酐 （ODPA）、3,3'',4,4''-二苯甲酮四甲酸二酐（BTDA）、3,3'',4,4''-联苯四羧酸二酐（BPDA）、4,4''-（六氟异丙烯）二酞酸酐（6FDA）和4,4''-(4,4''-异亚丙基二苯氧基)双(邻苯二甲酸酐)（BPADA）在间甲酚中通过一步法合成了五种聚酰亚胺（PI）。采用FTIR、1HNMR分析了聚合物的分子结构，用DSC、TGA、UV-Vis等仪器研究了聚合物的性能。结果表明，所制备的PI特性黏数在0.36~1.44 dL/g，在酚类溶剂中均具有良好的溶解性；PI的玻璃化转变温度（Tg）在184~243 ℃之间，氮气气氛下5%热失重温度为485~538 ℃，热稳定性优异；PI薄膜在400 nm处的透过率为24%~85%，500 nm的透过率可达69%~88%，截止波长区间308~367 nm，具有良好的透明性；PI薄膜的拉伸强度、杨氏模量和断裂伸长率分别在41.1~85.3 MPa、1.7~2.1 GPa和2.5~8.7%的范围内，具有良好的机械性能。     

Barrier and thermal properties of polyimide derived from a diamine monomer containing a rigid planar moiety

An aromatic polyimide (3,6‐CPI ) was prepared by the polymerization of pyromellitic dianhydride and diamine (3,6‐CDA ) containing a rigid planar carbazole moiety. The synthesized polyimide shows outstanding barrier properties with oxygen permeation rate and water vapor permeation rate low at 7.9 cm³ m^?2 day^?1 and 9.8 g m^?2 day^?1, respectively. Wide angle X‐ray diffraction, positron annihilation lifetime spectroscopy and molecular dynamics simulations reveal that the excellent barrier properties of 3,6‐CPI are mainly due to the crystallinity and low free volume of the polymer, which result from the rigid planar backbone structure and strong interchain hydrogen bonding. In addition, the polyimide exhibits excellent thermal stability and favorable mechanical properties with a 5 wt% weight‐loss temperature of 559 °C in nitrogen, a glass transition temperature (T _g) of 397 °C and a tensile strength of 115.4 MPa . The as‐synthesized polyimide shows potential packaging applications in the field of flexible electronics and displays, flexible and thin film photovoltaics, and light‐emitting diodes. © 2017 Society of Chemical Industry     

Synthesis,characterization, thermal and optical properties of soluble polyimides derived from an unsymmetrical diamine

A new unsymmetrical diamine monomer, 2,4‐diaminophenyl [4′‐(2′′,6′′‐diphenyl‐4′′‐pyridyl)phenyl]ether, was successfully synthesized by nucleophilic substitution of 1‐chloro‐2,4‐dinitrobenzene with 4‐(2′,6′‐diphenyl‐4′‐pyridyl) phenol. The diamine monomer was characterized by FTIR, ¹H and ¹³C NMR, and elemental analysis techniques and used for the preparation of novel polyimides (PIs) by reaction with commercially available tetracarboxylic dianhydrides such as pyromellitic dianhydride, 3,3′,4,4′‐benzophenone tetracarboxylic dianhydride, and bicyclo[2.2.2]‐oct‐7‐ene‐2,3,5,6‐tetracarboxylic dianhydride. These PIs with inherent viscosities ranged from 0.43 to 0.48 dL/g were readily soluble in many organic solvents and afforded tough and flexible films by solution casting. These polymers exhibited T_gs between 237 and 294°C, and 10% weight loss temperatures in excess of 500°C with up to 56% char yield at 600°C in air. Their maximum fluorescence emission in dilute (0.2 g/dL) NMP solution appeared at 450 nm. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis and characterization of polyimides with low dielectric constants from aromatic dianhydrides and aromatic diamine containing phenylene ether unit

New aromatic polyimides (PIs) having the lowest dielectric constant in nonfluorinated PIs have been developed from aromatic dianhydrides and an aromatic diamine containing phenylene ether units. The diamine monomer was prepared from 4-bromophenyl ether in five steps. Polycondensations were performed in 1-methyl-2-pyrrolidinone at room temperature for 18 h, giving poly(amic acid)s (PAAs) with inherent viscosities up to 0.53 dl/g. PAAs were converted to corresponding poly(imide)s (PIs) by thermal treatment at 300 °C. New PIs showed good thermal stability (5% weight loss around 450 °C) and the low dielectric constant (2.74).     

Synthesis and properties of polyimides containing bisphenol unit and flexible ether linkages

A series of novel polyimides was prepared from various diamines (with bisphenol units) and various aromatic tetracarboxylic dianhydrides via a two‐step (thermal imidization) method. The monomers and polymers were produced in high yields. The benzophenone series exhibited better solubility than the pyromellitic series and, especially, those with the alkyl (methyl)‐substituted ring exhibited good solubility and could be readily dissolved in polar aprotic solvents such as dimethylformamide and N,N′dimethylacetamide. The glass transition temperatures of all polyimides were found to be 235–322 and 223–332°C, respectively, by DSC and dynamic mechanical analysis. Thermogravimetric analyses indicated that the polymers were fairly stable up to 482–617°C (10 wt % loss in N₂) and 480–610°C (10 wt % loss in air). Wide‐angle X‐ray diffractograms revealed that most polyimides were predominantly amorphous. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 945–952, 2003     

基于一种含吡啶的氟化二胺的聚酰亚胺合成与性能

对苯二酚依次与2-氯-5-硝基三氟甲苯和2-氯-5-硝基吡啶进行亲核取代反应，还原后制备了一种含吡啶杂环的氟化二胺单体6-{4-[4-氨基-2-(三氟甲基)苯氧基]苯氧基}吡啶-3-胺，并采用两步法将其与二酐聚合，得到4种芳香族聚酰亚胺（PI）。对所得PI的溶解性、耐热稳定性、光学性能、力学性能进行了测试。结果表明，基于4,4’-氧双邻苯二甲酸酐和六氟二酐的PI在常见有机溶剂中均具有良好的溶解性。N2氛围下，这些PI的5%和10%热失重温度分别在548.8～594.2和566.3～609.7℃之间，玻璃化转变温度在226～290℃之间，具有良好的耐热稳定性。这些PI薄膜有较好的光学透明度和力学性能，截止波长在382～438 nm范围内，500 nm处的透过率在52%～78%范围内，拉伸强度为98.3～110.5 MPa，杨氏模量为1.86～2.14 GPa，断裂伸长率为9%～23%。     

Synthesis and characterization of organo‐soluble polyimides derived from a new spirobifluorene diamine

Polyimides exhibit outstanding thermal and thermo‐oxidative stability, excellent solvent resistance, good mechanical and electrical properties and superior chemical resistance. However, their practical applications are frequently limited by their infusible and insoluble nature. Structural modifications of the polymer backbone have been utilized to modify polyimide properties, either by reducing the interaction or by reducing the stiffness of the polymer backbone. Novel organo‐soluble polyimides containing spirobifluorene units were synthesized by the polycondensation of 2,7‐bis‐amino‐2′,7′‐di‐t‐butyl‐9,9′‐spirobifluorene with three aromatic dianhydrides. The one‐step polymerization procedure was conducted at 200 °C in m‐cresol, and the structures of the resulting polyimides were confirmed using infrared and NMR spectroscopy. The weight‐average molecular weights and polydispersities of the resulting polymers were in the ranges 20 600–341 000 and 1.02–1.30, respectively. The glass transition temperatures of the polyimides were in the range 289–322 °C, and the 10% weight loss in nitrogen appeared at a temperature higher than 435 °C and the residual weight at 800 °C was above 58%. The spiro segment has been introduced into polyimides, resulting in amorphous polyimides, conferring on them an enhanced solubility and leading to a significant increase in both glass transition temperature and thermal stability. These types of materials have potential for many applications. Copyright © 2010 Society of Chemical Industry     

含脂肪链的聚酰亚胺单体对称醚二胺的合成

以对氯硝基苯和脂肪二醇为原料,在无水碳酸钾作用下经缩合和Pd/C催化氢化还原得到4个对称型聚酰亚胺二胺单体。以1,2-二(对氨基苯氧基)乙烷为例,考察了物料配比、碳酸钾用量、反应压力、催化剂用量等因素对收率的影响,得到了缩合反应较佳工艺条件为:乙二醇3.1 g,碳酸钾用量为15.9 g,乙二醇和对氯硝基苯的摩尔比为1∶2.5,反应时长24 h;还原反应的较佳工艺条件为:压力为0.6 MPa,催化剂用量为0.30 g,温度70℃。在该条件下,1,2-二(对氨基苯氧基)乙烷两步总收率为74.1%,其余3个二胺单体的合成收率在49.4%~65.7%。     

Synthesis and properties of polyimides containing polybutadiene blocks

Polyimides containing polybutadiene blocks were prepared by copolycondensation of benzophenone-3,3′,4,4′-tetracarboxylic dianhydride, diphenylmethane-4,4′-diisocyanate and isocyanate-endcapped polybutadiene LBD-3000. ¹³C NMR CP-MAS and FTIR spectroscopies were used to determine the chemical structure of the copolymers. TGA showed that the thermal stability of the copolymers in inert atmosphere is almost independent of the polybutadiene content in the copolymer (as follows from the temperature of 10% and 20% weight loss). Stress–strain experiments showed that copolymers containing amounts of polybutadiene higher than 59 wt% exhibited elastomeric behaviour. © 1999 Society of Chemical Industry     

新型含吡啶环氟化二胺及其共聚聚酰亚胺的合成与性能

以3-羟基苯乙酮和苯甲醛为原料,通过改进的Chichibabin反应制备了4-苯基-2,6-双（3-羟基苯基）吡啶（m-PHPP）,再将其与2-氯-5-硝基三氟甲苯反应,合成了硝基化合物4-苯基-2,6-双[3-（4-硝基-2-三氟甲基苯氧基）苯基]吡啶（m,p-6FPNPP）,最后用Pd/C和水合肼将m,p-6FPN...     

Synthesis and properties of organosoluble polyimides based on novel flourene‐ring containing diacetamido‐diamine

A new diacetamido‐diamine monomer, N′‐[7‐(acetyl‐4‐aminoanilino)‐9,9‐dioctylflouren‐2‐yl]‐N′‐4‐aminophenyl) acetamide (ADOAc), with flourene‐based structure was prepared from the reaction of 4‐aminoacetanillide with 2,7‐dibromo‐9,9‐dioctylfluorene in the presence of 10 mol % CuI, 20 mol % N,N′‐dimethylethylene diamine as catalyst and K₂CO₃ as base. Two new flourene‐ring containing polyimides were prepared from the reaction of ADOAc with aromatic dianhydrides such as pyromellitic dianhydride (PMDA) and 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride (BTDA) via chemical imidization of poly(amic acid). The new diamine and the related polyimides were characterized by using conventional methods such as FT‐IR, NMR, and elemental analysis. The polyimides obtained from the reaction of ADOAc with PMDA (PIa) and of ADOAc with BTDA (PIb) had inherent viscosity of 0.49 and 0.58 dL/g respectively, and showed excellent solubility in a variety of organic solvents. The polyimides of PIa and PIb showed excellent thermal stability with 10% weight loss in nitrogen atmosphere at temperatures of 418°C and 407°C and T_g of 172°C and 167°C, respectively. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Soluble polyimides from unsymmetrical diamine containing benzimidazole ring and trifluoromethyl pendent group

New unsymmetrical diamine monomer containing both the benzimidazole ring and trifluoromethyl group, 6,4′-diamino-2′-trifluoromethyl-2-phenylbenzimidazole, was prepared from 2-bromo-5-nitrobenzotrifluoride and 4-nitro-1,2-phenylenediamine. The monomer was polymerized with ODPA, BTDA and 6FDA by using one-pot synthetic method to obtain corresponding polyimides. All the prepared polyimides were soluble in aprotic polar solvents. Incorporation of trifluoromethyl groups unsymmetrically in the rigid polyimides improves their solubility without decreasing their physical properties. The polymers showed high glass transition temperature (T_g = 289-352 °C), high thermal stability (T_d10 > 500 °C), and relatively low coefficient of thermal expansion (CTE = 26.1-46.4 ppm/°C) because of their rigid-rod like structure. Also, they showed low refractive indexes (n = 1.46-1.68) and low birefringence (Δ ≈ 0.02) due to the trifluoromethyl pendent groups that interrupt chain packing and increase free volume.     

Synthesis and properties of novel aromatic polyimides derived from bis(p-aminophenoxy)methylphenylsilane

A novel siloxane-containing diamine, bis(p-aminophenoxy)methylphenylsilane (BAMPS), was synthesized from the condensation of dichloromethylphenylsilane with p-aminophenol in the presence of triethylamine. A series of BAMPS-based aromatic polyimides were prepared from BAMPS and various aromatic tetracarboxylic dianhydrides by the usual two-step procedure including ring-opening polyaddition to poly(amic acid)s and subsequent cyclodehydration to polyimides. The inherent viscosities of poly(amic acid)s III_a - III_f ranged from 0.09 to 0.36 dL g⁻¹ in N,N-dimethylacetamide at a concentration of 0.5 g dL⁻¹ at 30°C. The inherent viscosities of polyimides were between 0.06 and 0.32 dL g⁻¹ in various solvents at 30°C. Polyimides, especially IV_c and IV_f , were soluble in a wide range of organic solvents such as N-methyl-2-pyrrolidinone, concentrated H₂SO₄, N,N-dimethylacetamide, N,N-dimethylformamide, and dimethyl sulfoxide. The polyimides were characterized by elementary analysis, IR spectra, TGA, and DSC. They also had glass transition temperatures ranging from 128 to 181°C. The 10% mass loss temperature was recorded in the range of 404–443°C in nitrogen and of 315–339°C in oxygen. © 1997 John Wiley & Sons, Inc.     

Syntheses and properties of polyimides derived from diamines containing 2,5‐disubstituted pyridine group

A series of novel homo‐ and copolyimides containing pyridine units were prepared from the heteroaromatic diamines, 2,5‐bis (4‐aminophenyl) pyridine and 2‐(4‐aminophenyl)‐5‐aminopyridine, with pyromelltic dianhydride (PMDA), and 3,3′, 4,4′‐biphenyl tertracarboxylic dianhydride (BPDA) via a conventional two‐step thermal imidizaton method. The poly(amic acid) precursors have inherent viscosities of 1.60–9.64 dL/g (c = 0.5 g/dL in DMAC, 30°C) and all of them can be cast and thermally converted into flexible and tough polyimide films. All of the polyimides show excellent thermal stability and mechanical properties. The polyimides have 10% weight loss temperature in the range of 548–598°C in air. The glass transition temperatures of the PMDA‐based samples are in the range of 395–438°C, while the BPDA‐based polyimides show two glass transition temperatures (T_g1 and T_g2), ranging from 268 to 353°C and from 395 to 418°C, respectively. The flexible films possess tensile modulus in the range of 3.42–6.39 GPa, strength in the range of 112–363 MPa and an elongation at break in the range of 1.2–69%. The strong reflection peaks in the wide‐angle X‐ray diffraction patterns indicate that the polyimides have a high packing density and crystallinity. The polymer films are insoluble in common organic solvents exhibiting high chemical resistance. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1844–1851, 2006     

Synthesis and characterization of addition-type polyimides functionalized with diamine chromophore

Summary The Bismaleimide-Diamine Chromophore (2) prepolymers were prepared in acetone. The structure of the prepolymer was characterized. The prepolymer exhibited excellent film-forming quality and good solubility in low boiling point solvent. Thermal and NLO properties of the cured polyimides were evaluated. The chromophore content strongly influenced the thermal properties and order parameter Φ. Received: 21 July 1998/Revised version: 25 August 1998/Accepted: 28 August 1998     

Poly(pyridinium salt)s with organic counterions derived from an aromatic diamine containing oxyethylene unit exhibiting amphotropic liquid-crystalline and photoluminescence properties

Several poly(pyridinium salt)s containing various organic counterions and oxyethylene unit in their backbones were synthesized by either the ring-transmutation polymerization reaction of 4,4′-(1,4-phenylene)bis(2,6-diphenylpyrylium tosylate) with 1,2-bis(4-aminophenoxy)ethane on heating in dimethyl sulfoxide or the metathesis reaction of the tosylate polymer with the corresponding lithium or sodium salts in acetonitrile. Their chemical structures were determined by ¹H and ¹³C NMR spectroscopy, and elemental analyses. Their number-average molecular weights and polydispersity indices were in the range of 59,000-63,000 and 1.41-1.65, respectively, as determined by gel permeation chromatography. They were characterized for their thermotropic and lyotropic liquid-crystalline properties by using differential scanning calorimetry and polarizing optical microscopy. Since these polymers exhibited liquid-crystalline phase both in the melt and in solutions, they belong to an amphotropic class of ionic polymers. Their light-emitting properties both in polar organic solvents and in films cast from methanol and acetonitrile were also studied by using spectrofluorometry.     

Synthesis and properties of novel soluble polyimides having a spirobisindane-linked dianhydride unit

A new synthetic procedure was elaborated allowing the preparation of semiaromatic dianhydride. N-Methyl protected 4-chlorophthalic anhydride was nitrated with HNO₃ to produce N-methyl-4-chloro-5-nitrophthalimide (1). The aromatic nucleophilic substitution reaction between 5,5′,6,6′-tetrahydroxy-3,3,3′,3′-tetramethyl-1,1-spirobisindane and 1 afforded spirobisindane-linked bis(N-methylphthalimide) (2), which was hydrolyzed and subsequently dehydrated to give the corresponding dianhydride (3). The latter was polymerized with five different aromatic diamines to afford a series of aromatic polyimides. The properties of polyimides such as inherent viscosity, solubility, UV transparency and thermal stability were investigated to illustrate the contribution of the introduction of spirobisindane groups into the polyimide backbone. The resulting polyimides were readily soluble in polar solvents such as chloroform, THF and N-methyl-2-pyrrolidone. The glass-transition temperatures of these polyimides were in the range of 254-292 °C. The tensile strength, elongation at break, and Young's modulus of the polyimide film were 68.8-106.6 MPa, 5.9-9.8%, 1.7-2.0 GPa, respectively. The polymer films were colorless and transparent with the absorption cutoff wavelength at 286-308 nm.     

Synthesis,thermal properties,and flame retardancy of phosphorus containing polyimides

Phosphorus containing polyimides were prepared via phosphorylation of organosoluble polyimides. This was achieved by phenoxaphosphine oxide ring formation reaction or esterification with diethylchlorophosphate. The phosphorylation was confirmed by infrared, ³¹P nuclear magnetic resonance, and elemental analysis for phosphorus. Polyimides containing phosphorus of 8.3 and 5.4% by weight were found. Thermal characteristics and decomposition behavior of the resulting polyimides were investigated by differential scanning calorimetry and thermogravimetric analysis. Introduction of phosphorus into polyimides slightly reduced their initial weight loss temperatures and led to high char yields at temperatures higher than 800°C. Limiting oxygen index values higher than 48 were found for the phosphorylated polyimides. Such properties make these polymers useful in flame retardant applications. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 63: 875–882, 1997     

Synthesis and properties of polyimides derived from cis- and trans-1,2,3,4-cyclohexanetetracarboxylic dianhydrides

Cis-1,2,3,4-cyclohexanetetracarboxylic dianhydride (cis-1,2,3,4-CHDA) was synthesized. It was found that under such conditions as heating or boiling in acetic anhydride, cis-1,2,3,4-CHDA could be converted to its trans-isomer. The process of thermal isomerization was monitored by ¹H NMR spectra and the mechanism of conversion was proposed. Their absolute structures of cis- and trans-1,2,3,4-CHDAs were elucidated by single crystal X-ray diffraction. The polycondensations of cis- and trans-1,2,3,4-CHDAs with aromatic diamines such as 4,4′-oxydianiline (ODA), 4,4′-methylenedianiline (MDA), 4,4′-diamino-3,3′-dimethyldiphenylmethane (DMMDA), 4,4′-bis(4-aminophenoxy)benzene (TPEQ), 2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP) were studied. It is easy to obtain higher molecular weight polyimides from trans-1,2,3,4-CHDA using conventional one-step or two-step methods. However, higher molecular weight polyimides derived from cis-1,2,3,4-CHDA could not be prepared by the usual methods (solid content ca. 10%) owing to the trend of forming cyclic oligomers. Increasing the concentration of monomers could give higher molecular weight cis-polymers. All of the cis-polyimides were soluble at room temperature in aprotic polar solvents and phenolic solvents and some of them even soluble in chloroform and tetrahydrofuran, while the corresponding trans-polymers showed poor solubility as compared to cis-polymers. All of the polyimides showed good thermal stability with the 5% weight loss temperatures in air over 415 °C. Furthermore, polyimides derived from cis-1,2,3,4-CHDA have higher glass transition temperatures (T_gs) than corresponding trans-polyimides. The flexible polyimide films possessed a tensile modulus range of 2.1-3.6 GPa, a tensile strength range of 42-116 MPa, an elongation at break of 4-18%. These polyimides exhibited cutoffs at wavelengths around 270 nm and were entirely colorless. All the polyimides showed amorphous pattern according to Wide angle X-ray diffraction measurements. The differences of polymerization and properties were explained by the structural changes resulted from isomerism.