Preparation and properties of novel fluorinated polyimides based on 2,2′,6,6′-tetrafluorobenzidine

Fluorinated polyimides were prepared from 2,2′,6,6′-tetrafluorobenzidine and four conventional dianhydride monomers by a solution polycondensation reaction followed by a chemical imidization. Polyimide based on 2,2′,6,6′-tetrafluorobenzidine and hexafluoroisopropylidene bis(3,4-phthalic anhydride) (6FDA) is soluble in organic solvents such as NMP, DMA, DMF, THF, chloroform, and acetone while those based on 2,2′,6,6′-tetrafluorobenzidine and pyromellitic dianhydride (PMDA), benzophenone-3,3′,4,4′-tetracarboxylic acid dianhydride (BTDA), diphenylether-3,3′,4,4′-tetracarboxylic acid dianhydride (ETDA) are not. Polyimide from 2,2′,6,6′-tetrafluorobenzidine and 6FDA possesses high optical transparency at 350–700 nm and has a in-plane refractive index of 1.558 at 632.8 nm. All polyimides exhibit glass transition temperatures above 350°C. They also possess very high thermal stability. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 1605–1609, 1998     

Synthesis and characterization of polyimides from 4‐(diphenyl phosphine oxide)phenyl pyrromellitic dianhydride

A novel rigid‐rod type dianhydride monomer with phosphine oxide moiety, 4‐(diphenyl phosphine oxide)phenyl pyrromellitic dianhydride (POPPMDA), was synthesized via the Suzuki coupling reaction of 4‐(diphenyl phosphine oxide)phenyl boronic acid (POBB) and 1‐bromo‐2,3,5,6‐tetramethyl benzene (B4MB), followed by oxidation and cyclodehydration. The monomer was characterized by FTIR, NMR, EA, and melting point analyzer and utilized to synthesize polyimides with diamines such as bis(3‐aminophenyl)phenyl phosphine oxide (mDAPPO) and p‐phenylene diamine (pPDA) by varying their ratio. The polyimides were prepared via a conventional two‐step synthesis: preparation of poly(amic‐acid), followed by solution imidization. The polyimides were characterized by FTIR, NMR, DSC, TGA, and TMA, and their solubility, intrinsic viscosity, and adhesive properties were also evaluated. The polyimides exhibited high T_g (342–362°C), good thermal stability (>500°C), excellent adhesive property (134–107 g/mm), and low CTE (28–17 ppm/°C). © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Effects of dianhydrides on the thermal behavior of linear and crosslinked polyimides

To determine the thermal characteristics of linear and crosslinked polyimides (PIs), BTDA, ODPA, and 6FDA were used to synthesize polyimides. Thermal degradation temperature and glass transition temperature of the resulting PIs were measured using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). To measure the change in modulus and coefficient of thermal expansion (CTE) depending on dianhydride structure, a dynamic mechanical analyzer (DMA) and thermo‐mechanical analyzer (TMA) were used. The thermal degradation and glass transition temperature properties of linear PIs varied according to whether the linear chain adopted a bulky or flexible structure. Dynamic modulus and thermal expansion values of linear polyimides also showed good agreement with the TGA and DSC results. As we expected, linear polyimide with bulky 6FDA groups showed better thermal behavior than the flexible polyimides. Crosslinked polyimide nadic end‐capped (norbornene) with a bulky dianhydride group had a lower thermal degradation temperature and higher CTE than flexible BTDA and ODPA polyimides. Our results indicate that the mobility of the dianhydride group affects the thermal behaviors of linear and crosslinked polyimides in different ways. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41412.     

共聚型聚酰亚胺热亚胺化动力学研究

为考察共聚体系的热亚胺化动力学,今以4,4’-二氨基二苯醚(ODA),均苯二酐(PMDA),3,3’,4,4’-二苯酮二酐(BTDA)为单体合成共聚型聚酰胺酸(PAA),通过差示扫描量热分析(DSC)法测量PAA亚胺化动力学,并通过红外光谱分析仪 FT-IR 分析聚酰亚胺(PI)亚胺化程度,万能试验机测试共聚物力学性能.结果表明:随着柔性二酐(BTDA)的引入,聚合物分子链柔性增强,DSC图谱上反应出亚胺化反应相对平缓.动力学数据显示,二酐共聚体系亚胺化反应活化能最小,端基间碰撞克服的能垒最低,有利于亚胺化的进行.     

Syntheses and properties of novel polyimides derived from 2‐(4‐Aminophenyl)‐5‐aminopyrimidine

2‐(4‐Aminophenyl)‐5‐aminopyrimidine (4) is synthesized via a condensation reaction of vinamidium salts and amidine chloride salts, followed by hydrazine palladium catalyzed reduction. A series of novel homo‐ and copolyimides containing pyrimidine unit are prepared from the diamine and 1,4‐phenylenediamine (PDA) with pyromellitic dianhydride (PMDA) or 3,3′,4,4′‐biphenyl tertracarboxylic dianhydride (BPDA) via a conventional two‐step thermal imidization method. The poly(amic acid) precursors had inherent viscosities of 0.97–4.38 dL/g (c = 0.5 g/dL, in DMAc, 30°C) and all of them could be cast and thermally converted into flexible and tough polyimide films. All of the polyimides showed excellent thermal stability and mechanical properties. The glass transition temperatures of the resulting polyimides are in the range of 307–434°C and the 10% weight loss temperature is in the range of 556–609°C under air. The polyimide films possess strength at break in the range of 185–271 MPa, elongations at break in the range of 6.8–51%, and tensile modulus in the range of 3.5–6.46 GPa. The polymer films are insoluble in common organic solvents, exhibiting high chemical resistance. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5871–5876, 2006     

Characterization of alicyclic polyimides based on cyclobutane ring dianhydride and aromatic diamine

Films of alicyclic polyamic acid and polyimide containing cyclobutane ring in dianhydride moiety and aromatic ring with p- or m-linkages in diamine moiety were characterized by infrared (IR) spectroscopy, dynamic viscoelasticity, differential-scanning calorimetry (DSC), density, and wide-angle X-ray diffraction analyses. Partially and fully imidized polyimides were obtained by varying the imidization temperature, e.g., 150°C, 250°C, and 350°C. It was found from the results of IR spectra, dynamic viscoelasticity, and DSC measurements that the imidization of alicyclic polyamic acid was reduced at about 150°C and needed a higher imidization temperature than aromatic polyamic acid. Alicyclic polyimide with m-linkage in the diamine moiety had a higher density and a much more ordered structure than with p-linkage. © 1994 John Wiley & Sons, Inc.     

Introduction of side chains containing biphenyl unit on the crystalline morphology and properties of polyimides

Several polyimides derived from 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride (BTDA) and 3,5‐diaminobenzate containing various side chains with biphenyl unit through various flexible spacer were prepared by thermal imidization. By incorporating side chains, the solubility was greatly enhanced and all the polyimides with side chains showed good solubility in polar solvents. During a continuous thermal imidization procedure, the BTDA/MPDA polyimide samples formed a novel banded spherulites with not only zigzag Maltese crosses, but also distinct extinction rings, while the polyimides with side chains revealed only fine grainy crystalline particle. X‐ray diffraction of BTDA/MPDA powder showed sharp diffraction peak in the X‐ray diffraction and revealed the existence of highly ordered crystalline structure in polyimide, while BTDA/PP0DA, BTDA/PP2DA, and BTDA/PP6DA polyimides with side chains revealed only a broad reflection at the low angle and demonstrated the presence of low‐ordered layer structure. DSC confirmed that the introduction of side chains significantly reduced the melting points of the resulted polyimide, thus it greatly enhanced its thermal plasticity. However, the heat‐resistant properties such as the thermal stability were generally decreased, and all the polyimide with side chains showed a typical two‐step thermal degradation behavior relating to the pyrisis of side chains and polyimide backbone. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2255–2260, 2006     

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     

Preparation of organo‐soluble co‐polyimides using N‐methyl‐2‐pyrrolidone as the solvent via one‐pot high‐temperature polymerization

A series of organo‐soluble co‐polyimides (co‐PIs) were successfully synthesized from 3,3′,4,4′‐benzophenonetetracarboxylic‐dianhydride (BTDA), 1,4‐bis‐(4‐amino‐2‐trifluoromethyl‐phemoxy)‐benzene (p‐6FAPB) and 2‐(4‐aminophenyl)‐5‐aminobenzimidazole (BIA) via the one‐pot high‐temperature polymerization using N‐methyl‐2‐pyrrolidone (NMP) as the solvent. The imidization reaction of poly(amic acid)s in solution state was discussed in detail by attenuated total reflectance‐Fourier transform infrared spectra (ATR‐FTIR), and the results illustrate that the introduced benzimidazole moiety has a catalytic activity on the imidization process. The number‐average molecular weights and polydispersity index of these PIs measured by gel permeation chromatography range from 1.11 × 10⁵ to 2.20 × 10⁵ and 1.82 to 3.84, respectively. The prepared co‐PIs exhibit sufficient solubility in some polar solvents and high optical transparency. Meanwhile, these co‐PI films show good mechanical performances, and the strength and modulus of the sample with the molar ratio of p‐6FAPB/BIA = 5/5 reach 183 MPa and 4.71 GPa, respectively. Moreover, the obtained co‐PIs possess high glass transition temperatures (T_g) (above 260 °C) and good thermal stability with 5% weight loss temperature in the range of 502–531 °C in the nitrogen atmosphere. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45497.     

以BAPP为原料的热塑性PI薄膜的合成及性能

以芳香长链二胺2,2-双[4-(4-氨基苯氧基)苯基]丙烷(BAPP)为二胺原料,与最具商业价值的四种酸酐均苯四甲酸二酐(PMDA)、3,3′,4,4′-联苯四酸二酐(BPDA)、3,3′,4,4′-二苯酮四酸二酐(BTDA)、3,3′,4．4′-二苯醚四酸二酐(ODPA)为二酸酐原料,采用二步溶液缩聚法制得了一系列均聚和共聚聚酰亚胺薄膜。利用FTIR表征了聚酰亚胺的结构,并用DSC、TOA、TMA DMA等手段测得了不同聚酰亚胺的Tg、5%与10%热失重温度、线膨胀系数、拉伸强度、断裂延伸率、热压粘接T型剥离强度等性能数据。     

Polyimides from isomeric biphenyltetracarboxylic dianhydrides and the effects of chemical structure on solubility

A series of homopolyimides and copolyimides was synthesized by the solution condensation of biphenyltetracarboxylic dianhydride (BPDA) isomers and various diamines followed by chemical imidization. These polyimides had intermediate to high molecular weights with inherent viscosities of 0.34–1.01 dL/g for homopolyimides and 0.48–1.02 dL/g for copolyimides. Thermogravimetric analysis indicated that the aromatic polyimides were stable up to 500°C, and the 5% weight loss temperatures were recorded in the range of 506–597°C in an air atmosphere and in the range of 517–601°C in a nitrogen atmosphere, depending on the diamines used. The glass transition temperatures of aromatic homopolyimides were above 271°C, while the glass transition temperatures of the copolyimides increased with an increase in the 2, 2′, 3, 3′‐BPDA‐component. The effects of the chemical structure of the polymer chain on the solubility were investigated. It was found that the solubility of BPDA‐based polyimides could be improved by the introduction of flexible units, nonlinear and non‐coplanar units, and copolymerization. The polyimides with nonlinear and non‐coplanar units derived from 2, 2′, 3, 3′‐BPDA appeared to have prominently enhanced solubility in polar aprotic solvents and polychlorocarbons when compared with the homopolyimide derived from 3, 3′, 4, 4′‐BPDA.     

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     

Adhesion property of novel polyimides with 1‐[3′,5′‐bis(trifluoromethyl)phenyl] pyromellitic dianhydride

Novel polyimides were synthesized from 1‐[3′,5′‐bis(trifluoromethyl)phenyl] pyromellitic dianhydride (6FPPMDA) by a conventional two‐step process: the preparation of poly(amic acid) followed by solution imidization via refluxing in p‐chlorophenol. The diamines used for polyimide synthesis included bis(3‐aminophenyl)‐3,5‐bis(trifluoromethyl)phenyl phosphine oxide, bis(3‐aminophenyl)‐4‐trifluoromethylphenyl phosphine oxide, and bis(3‐aminophenyl)phenyl phosphine oxide. The synthesized polyimides were designed to have a molecular weight of 20,000 g/mol by off‐stoichiometry and were characterized by Fourier transform infrared, NMR, differential scanning calorimetry, and thermogravimetric analysis. In addition, their intrinsic viscosity, solubility, water absorption, and coefficient of thermal expansion (CTE) were also measured. The adhesion properties of the polyimides were evaluated via a T‐peel test with bare and silane/Cr‐coated Cu foils, and the failure surfaces were investigated with scanning electron microscopy. The 6FPPMDA‐based polyimides exhibited high glass‐transition temperatures (280–299°C), good thermal stability (>530°C in air), low water absorption (1.46–2.16 wt %), and fairly low CTEs (32–40 ppm/°C), in addition to good adhesion properties (83–88 g/mm) with silane/Cr‐coated Cu foils. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1801–1809, 2005     

化学亚胺化合成含吡啶环共聚聚酰亚胺

用2,2-双[4-（4-氨基苯氧基）苯基]丙烷（BAPP）和4-苯基-2,6-双（4．氨基苯基）吡啶（PBAP）作为二胺,3,3’,4,4＇-二苯酮四酸二酐（BTDA）作为二酐,以N,N-二甲基甲酰胺（DMF）为溶剂,合成了3种聚酰亚胺。先用BAPP和PBAP同BTDA反应生成一系列聚酰胺酸（PAA）,然后将得到的PAA用化学亚胺化制备相应的聚酰亚胺。用FT-IR、^1H—NMR、粘度测试、溶解性测试和TGA对聚合物的结构和性能进行了表征。结果表明,FT—IR测试在1780cm^-1、1720cm^-1和725cm^-1左右出现了聚酰亚胺的特征吸收峰,所得聚酰胺酸的特性粘数为0．32～0．46dL／g,大部分聚酰亚胺在常见有机溶剂NMP中可溶,它们有很好的热稳定性,氮气氛中,在500℃以前没有明显的降解。     

Synthesis and property measurements of polyimides with substituted pyromellitic dianhydride for flexible printed circuits applications

Pyromellitic dianhydride‐based dianhydrides with bulky substituents, such as 1‐phenyl pyromellitic dianhydride and 1‐(4′‐trifluoromethylphenyl)pyromellitic dianhydride, were combined with bis(3‐aminophenyl)phenylphosphine oxide and 4,4′‐phenylene diamine to prepare polyimides with low coefficient of thermal expansion (～ 17 ppm/°C) and good adhesion (>100 g/mm). The polyimides were synthesized via a conventional two‐step process: preparation of poly(amic‐acid) followed by solution imidization with o‐dichlorobenzene. The molecular weights of the polyimides were controlled to 25,000 g/mol via off‐stoichiometry and the synthesized polyimides were characterized by Fourier transform infrared, nuclear magnetic resonance, differential scanning calorimetry, and thermogravimetric analysis. Their intrinsic viscosity and solubility were also measured, while adhesive property was measured via T‐peel test samples of Cu/polyimide. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis and characterization of new water-soluble precursors of polyimides

We have successfully synthesized and characterized new water-soluble precursors of polyimides based on dianhydrides with diaminobenzene sodium sulfonate (DABSS) and diaminostilbene disodium sulfonate (DASBDSS). The precursors are soluble in water and methanol as well as in several aprotic solvents. The optimum inherent viscosities of the poly(amic acids), obtained by varying reaction temperatures, were measured using a conventional Ubbelohde viscometer. The average molar mass of the polymers expressed as the “poly(ethylene oxide)-PEO/poly(ethylene glycol)-PEG equivalent” molecular masses obtained by gel permeation chromatography (GPC) showed significant broad molecular mass distributions with their polydispersities ranging from 2.9 to 4.6. FT-IR spectra revealed complete imidization of the polyimides. Their thermal properties were studied by techniques such as differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). Polyimides derived from the dianhydrides and DASBDSS showed better thermal stability up to 40°C in nitrogen than in oxygen atmosphere. However, polyimides based on the dianhydrides and DABSS were slightly more stable in oxygen than in nitrogen atmosphere. In oxygen, all the synthesized polyimides exhibited weight losses of about 50% in the range of 450–510°C. The overall weight losses of these polyimides under nitrogen were less than 50% at 700°C. New network polymellitimides based on mellitic trianhydride (MTA) and DABSS, and co-polymellitimides based on MTA, DABSS, and ODA (oxydianiline) were also synthesized and characterized successfully. Their thermal stabilities were compared with the linear polyimides using TGA and DSC.     

Polyimide foams with ultralow dielectric constants

To explore ultralow dielectric constant polyimide, the crosslinked polyimide foams (PIFs) were prepared from 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride (BTDA), 4,4′‐oxydianiline (ODA), and 2,4,6‐triaminopyrimidine (TAP) via a poly(ester–amine salt) (PEAS) process. FTIR measurements indicated that TAP did not yield a negative effect on imidization of PEAS precursors. SEM measurement revealed the homogeneous cell structure. Through using TAP as a crosslinking monomer, the mechanical properties of PIFs could be improved in comparison with uncrosslinked BTDA/ODA based PIF. The crosslinked PIFs still exhibited excellent thermal stability with 5% weight loss temperatures higher than 520°C. In the field with frequency higher than 100 Hz, the dielectric constants of the obtained PIFs ranged from 1.77 to 2.4, and the dielectric losses were smaller than 3 × 10^?2 at 25–150°C. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1734–1740, 2006     

Polyimides 7: Synthesis,characterization, and properties of novel soluble semifluorinated poly(ether imide)s

Three novel diamine monomers ( VI , VII , and VIII ) were synthesized. These diamine monomers lead to a number of semifluorinated poly(ether imide)s when reacted with different commercially available dianhydrides like pyromellitic dianhydride (PMDA), benzophenone tetracarboxylic acid dianhydride (BTDA), 2,2‐bis (3,4‐dicarboxyphenyl) hexafluoropropene (6FDA), and oxydiphthalic dianhydride (ODA) by thermal imidization route. Elemental analyses, IR and NMR techniques were used to characterize the monomers and polymers. The resulting polymers exhibited weight average molar masses up to 1.78 × 10⁵ g mol^?1 in GPC with respect to polystyrene standard and have very good solubility in several organic solvents such as NMP, DMF, DMAC, DMSO, chloroform, and THF. Very good solubility of these polymers in CDCl₃ enables their complete characterization by proton as well as ¹³C‐NMR techniques. The polymers showed very high thermal stability with decomposition temperature (5% weight loss) up to 511°C in air and high glass transition temperature up to 311°C depending upon the exact repeating unit structure. The polymer films showed high modulus (up to 2.9 GPa) as was evaluated by DMA. The polymers also showed very low water absorption (0.16%), low dielectric constant (2.35 at 1MHz) and very good optical transmission. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3025–3044, 2007     

Novel poly(thiourea‐ether‐imide)s derived from 4,4′‐oxydiphenyl‐bis(thiourea): probing the possibility for high‐temperature applications

Our interest in the fabrication of high‐performance polyimides has led to thiourea‐substituted poly(thiourea‐ether‐imide)s (PTEIs) with good retention of thermal properties along with flame retardancy. A new aromatic monomer, 4,4′‐oxydiphenyl‐bis(thiourea) (ODPBT), was efficiently synthesized and polymerized with various dianhydrides (pyromellitic dianhydride, 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride and 4,4′‐(hexafluoroisopropylidene)diphthalic dianhydride) via two‐stage chemical imidization to fabricate a series of PTEIs. The structural characterization of ODPBT and the polymers was carried out using Fourier transform infrared, ¹H NMR and ¹³C NMR spectral techniques along with crystallinity, organosolubility, inherent viscosity and gel permeation chromatographic measurements. PTEIs bearing C?S and ? O? moieties in the backbone demonstrated an amorphous nature and were readily soluble in various amide solvents. The novel polymers had inherent viscosities of 1.16–1.23 dL g^?1 and molecular weights of ca 90 783–96 927 g mol^?1. Their thermal stability was substantiated via 10% weight loss in the temperature range 516–530 °C under inert atmosphere. The polyimides had glass transition temperatures of 260–265 °C. Incorporation of thiourea functionalities into polymer backbones is demonstrated to be an effective way to enhance their thermal properties and flame retardancy. Thus, ODPBT can be considered as an excellent candidate for use in the synthesis of high‐performance polymeric materials. Copyright © 2010 Society of Chemical Industry     

Synthesis and properties of highly branched poly(urethane–imide) via A2 + B3 approach

A series of highly branched poly(urethane–imide) (HBPUI) were synthesized via A₂ + B₃ approach using isophorone diisocyante (IPDI), polycarbonatediol (PCDL), 3,3′,4,4′-Benzophen-onetetracarboxylic dianhydride (BTDA), and poly(oxyalkylene) triamine (ATA) as materials. The structure of the products was characterized by FT-IR and ¹³C-NMR. The molecular weights were characterized by gel permeation chromatograph (GPC). The solution viscosity, thermal, and mechanical properties were measured by rotational rheometer, differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), tensile tests, and dynamic mechanical analysis (DMA), respectively. The HBPUI showed lower viscosity than that of linear poly(urethane–imide) (LPUI), nevertheless T _g of HBPUI was higher than that of LPUI. TGA indicated that the thermal degradation of poly(urethane–imide) occurred above 300 °C, which was higher than conventional polyurethane. The tensile strength of HBPUI was obviously improved by increasing the content of BTDA and the molar ratio of [A₂]/[B₃]. The effects of the content of BTDA and the molar ratio of [A₂]/[B₃] on the storage modulus of the polymers were also studied.