共缩聚聚酰胺酸和聚酰亚胺的微波辐射合成研究

在N,N′-二甲基甲酰胺(DMF)溶剂中,选用3,3,′4,4′-二苯酮四羧酸二酐(BTDA)、均苯四甲酸酐(PMDA)和4,4′-二氨基二苯醚(ODA)为单体,微波辐射低温溶液缩聚合成一种共缩聚聚酰亚胺的前驱体聚酰胺酸(PAA),然后亚胺化脱水环化生成共缩聚聚酰亚胺(PI)。通过特性黏数([η])、红外光谱(FT-IR)和热重分析(TGA)对聚合物进行了结构表征和性能测试。结果表明,微波辐射溶液聚合能够提高PAA的特性黏数及产率,微波的引入大大缩短了反应时间;IR表明,在1778 cm-1和1723 cm-1处观察到聚酰亚胺特征峰;TG表明,PI在氮气中535℃左右开始降解,10%热失重温度(Td10%)为587℃。     

BTDA型聚酰胺酸和聚酰亚胺的微波辐射合成

在微波辐射条件下,将3,3′,4,4′-二苯酮四羧酸二酐(BTDA)、4,4′-二氨基二苯醚(ODA)和3,5-二氨苯甲酸(DABA)在少量非极性溶剂N,N′-二甲基甲酰胺(DMF)的存在下进行共缩聚反应,快速而高效地合成了聚酰胺酸(PAA)和聚酰亚胺(PI)。采用特性粘数、红外光谱(FT-IR)和核磁共振(1HNMR)对聚合物的结构进行了表征,利用热失重分析(TGA)对其热性能进行了测试,并测定了聚合物在多种溶剂中的溶解性。实验结果表明,微波辐射溶液聚合能够提高PAA的特性粘数及产率,微波的引入大大缩短了反应时间;FT-IR表明,在1779cm-1、1723cm-1、1239cm-1和1378cm-1处观察到聚酰亚胺特征峰;TG表明,PI在氮气中10%热失重温度(Td10%)为576℃。     

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.     

一种新型共聚酰亚胺的合成与表征

以3,3’-二氨基二苯砜（DDS）和4,4’-二氨基二苯醚（ODA）作为共缩聚二胺单体,与3,3’,4,4’-二苯酮四羧酸二酐（BTDA）进行缩合聚合,合成了一系列具有一定溶解性的共聚酰亚胺。采用升温红外光谱监控了聚酰胺酸热环化为聚酰亚胺的过程,对所得产物的热稳定性和力学性能进行研究,发现二胺单体的组成对共聚酰亚胺的性能产生较为明显的影响。     

含酮柔性共聚型聚酰亚胺性能研究

为了考察柔性二酐共聚对聚酰亚胺(PI)薄膜性能的影响,用含柔性基团的酮酐单体3,3',4,4'-二苯酮四酸二酐(BTDA)、刚性二酐单体均苯四甲酸二酐(PMDA)和芳香二胺4,4'-二氨基二苯醚(ODA)共聚,制得共聚聚酰亚胺薄膜.分别用FT-IR(ATR)、TMA、TGA、万能试验机对薄膜的结构、热性能及力学性能进行了测定.结果表明,聚合物亚胺化程度完全,且随着柔性二酐的加入聚合物的热性能得到明显改善,同时力学性能数据也表明,共聚物柔性增强,材料的加工性得到提高.     

含烷基取代基柔性聚酰亚胺薄膜的制备

以柔性二胺单体1,3-双(4-氨基苯氧基)苯(134BAPB)和含支链二胺单体3,3′-二乙基-4,4′-二氨基二苯甲烷(DEMMD)与3,3′,4,4′-二苯酮四酸二酐(BTDA)进行三元共聚,制备了一系列聚酰亚胺(PI)薄膜。通过傅里叶红外光谱、差示扫描量热仪、热重分析仪、热机械分析仪及电子万能材料试验机对材料的结构、热性能和力学性能进行了表征。结果表明PI薄膜已经成功制备,热性能与力学性能良好。     

PAPP/ODA共聚聚酰亚胺的制备与性能

以4–苯基–2,6–双[4–(4–氨基苯氧基)苯基]吡啶和4,4′–二氨基二苯醚为二胺单体,3,3′,4,4′–二苯酮四羧酸二酐为二酐单体,N–甲基–2–吡咯烷酮为溶剂,通过一次加料,得到共聚聚酰亚胺。用傅立叶变换红外光谱仪、差示扫描量热仪、热重分析仪、X射线衍射仪、溶解性测试等对共聚聚酰亚胺的结构和性能进行了表征。研究结果表明,所得聚合物在1 780,1 723,1 380 cm-1左右出现了聚酰亚胺的特征吸收峰,实验所得的聚酰亚胺能很好地溶解在常见有机溶剂中,玻璃化转变温度为246℃,氮气气氛中,10%的热失重温度为505℃,800℃的残余率为48%。     

含苯并双咪唑高阻燃共聚聚酰亚胺薄膜的制备及其性能研究

以二胺单体2,2′-对苯基双-(5-氨基苯并咪唑)(PBABI)、 1,4-二氨基苯二胺(p-PDA)与二酐单体3,3′,4,4′-联苯四甲酸二酐(BPDA)进行共聚,制备高相对分子质量的聚酰亚胺(PI)前驱体聚酰胺酸(PAA),再通过热酰亚胺化的方式得到含苯并双咪唑重复单元的高阻燃共聚PI薄膜;研究了PI薄膜的聚集态结构、化学结构、热稳定性、阻燃性能和力学性能。结果表明:随着苯并双咪唑单体的增多,PI薄膜逐渐从有序堆积向无定型结构演变;苯并双咪唑结构促进了PI薄膜体系中形成分子间氢键作用;苯并咪唑的引入使PI薄膜的最大热分解温度提高5℃、玻璃化转变温度提升90℃、拉伸强度提高126 MPa,同时含苯并双咪唑的PI薄膜表现出优异的阻燃性能,极限氧指数提高到54%。     

一种三元共聚型聚酰亚胺的制备与表征

以3,3'-二甲基-4,4'-二氨基二苯甲烷、1,3-双(4-氨基苯氧基)苯(1,3-APB)与3,3',4,4'-二苯醚四羧酸二酐(ODPA)进行缩聚反应,制得一种新型的三元共缩聚型聚酰亚胺。将此聚合物与两种二元共缩聚型聚酰亚胺的性能进行对此,发现三元共聚型聚酰亚胺的溶解性能、力学性能和热性能皆较好,且使用范围扩大。     

基于酚酞结构高可溶性聚酰亚胺的合成与性能

以百里香酚酞、对氟硝基苯为起始原料,通过芳香亲核取代和氧化还原反应得到新型芳香二胺单体5,5’-二异丙基-4,4’-二氨基苯氧基-2,2’-二甲基酚酞。该二胺单体分别与3,3’,4,4’-二苯醚四甲酸二酐、3,3’,4,4’-二苯酮四羧酸二酐和3,3’,4,4’-联苯四甲酸二酐以一步法高温缩聚制得了一系列同时含酚酞Cardo结构及异丙基和甲基侧基的高可溶性聚酰亚胺(PI-1、PI-2和PI-3)。该系列聚酰亚胺具有优异的溶解性,室温下不仅可溶于高沸点溶剂N-甲基吡咯烷酮、N,N-二甲基乙酰胺、N,N-二甲基甲酰胺、二甲基亚砜,而且能溶于低沸点溶剂氯仿,二氯甲烷和四氢呋喃,可通过其溶液浇铸制得一系列高性能聚酰亚胺薄膜。所制聚酰亚胺薄膜具有较高的光学透明性,截断波长在324～365 nm之间,450 nm的透过率在56%～78%之间。该系列薄膜玻璃化转变温度在266～289℃之间,在N₂和O₂下10%热失重温度均≥432℃。其拉伸强度在77～95 MPa之间,断裂伸长率在9.1%～13.0%之间,1 MHz下介电常数为2.79～3.01 F/m,...     

双酚A型二胺和二酐合成可溶性聚酰亚胺的研究

采用2,2-双[4-(4-氨基苯氧基)苯基]丙烷(BAPP)和2,2-双[4-(3,4-二羧基苯氧基)苯基]丙烷二酐(BPADA)为单体,N,N-二甲基甲酰胺(DMF)为溶剂,通过常规的两步法,并分别经热亚胺化和化学亚胺化过程合成了双酚A型聚酰亚胺(PI).用FTIR、DSC、TGA等对聚合物的结构和性能进行了表征.F...     

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。     

亚胺化对聚酰亚胺热学性能的影响

用均苯四甲酸二酐(PMDA)与4,4’-二氨基二苯醚(ODA)为单体,聚合得到一定表观黏度的聚酰胺酸(PAA)。通过调节温度和时间两个变量,并采用红外光谱仪、高温综合热分析试着分别对PAA凝胶膜热亚胺化过程以及热学稳定性进行了研究,结果表明:亚胺化程度随时间的增加而增大,亚胺化程度随着亚胺化温度的提高同样增大;通过热重分析仪对聚酰亚胺薄膜热学性能进行了研究,随着薄膜亚胺化程度的增大,薄膜的热稳定性提高。     

Preparation of poly(amic acid) and polyimide derived from 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride with different diamines by microwave irradiation

Polycondensation‐type poly(amic acid) (PAA) was synthesized with 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride as a dianhydride monomer and 4,4′‐diaminodiphenylmethane and 4,4′‐oxydianiline as diamine monomers under microwave irradiation in dimethylformamide. Then, PAA was used to make polyimide (PI) by imidization at a low temperature. The structure and performance of the polymers were characterized with Fourier transform infrared (FTIR), proton nuclear magnetic resonance (¹H‐NMR), viscosity, X‐ray diffraction (XRD), and thermogravimetry (TG) curve analyses. The FTIR spectra of the polymers showed characteristic peaks of PI around 1779 and 1717 cm^?1. The ¹H‐NMR spectrum of PAA indicated a singlet at 6.55 ppm assigned to ? NHCO? and a singlet at 10.27 ppm assigned to carboxylic acid protons. The XRD spectrum demonstrated that the obtained PI had a low‐order aggregation structure with a d‐spacing of 0.5453 nm. The TG results revealed that the PI was thermally stable with 10% weight loss at 565°C in an N₂ atmosphere. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

Microwave assisted polycondensation of polyimides by [4,4′‐(hexafluoroisopropylidene)diphthalic anhydride,pyromellitic dianhydride] and [2,4,6‐trimethyl‐m‐phenylenediamine]. Power,time, and solvent effect

The microwave assisted polycondensation of two polyimides were studied using pyromellitic dianhydride (PMDA), and 4,4′‐(hexafluoroisopropyliden)diphthalic anhydride (6FDA) as dianhydride monomers and 2,4,6‐trimethyl‐m‐phenylenediamine (TrmPD), as diamine monomer, under microwave irradiation in DMF and DMSO solvents. The structure and performance of polymers were characterized by Fourier Transform Infrared Spectroscopy (FTIR), viscosity, density, and Thermogravimetric Analysis (TGA). The results show that the polyimides can be obtained in a short reaction time with high intrinsic viscosity and high yield. The effect of the presence of a bridging group, ? C(CF₃)₂? , in the monomer structure is apparent in the permeability parameters of the macromolecules as polymer (6FDA‐TrmPD) always presents better results than polymer (PMDA‐TrmPD). Properties as density and T_g increases with the time exposition to the microwave irradiation. Polyimides obtained present good thermal properties because they began to lose weight in a range of 8–16% at high temperature as 450°C. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

DABA-BAPP-BPADA共聚聚酰亚胺的合成与性能

用2,2-双[4-(4-氨基苯氧基)苯基]丙烷(BAPP)及3,5-二氨基苯甲酸(DABA)作为二胺,2,2-双[4-(3,4-二羧基苯氧基)苯基]丙烷二酐(BPADA)作为二酐,以N,N-二甲基甲酰胺(DMF)为溶剂,通过常规的两步法,分别经热亚胺化和化学亚胺化过程合成了可溶性共聚聚酰亚胺。用FT-IR对聚合物的结构进行了表征,性能测试采用了溶解性测试、DSC、TGA、拉伸测试和吸水率测试。FT-IR图谱表明,在1 780cm~(-1)、1720 cm~(-1)和740 cm~(-1)左右出现了聚酰亚胺的特征吸收峰。共聚聚酰亚胺在常见有机溶剂中可溶,并且有很好的热稳定性,玻璃化转变温度T_g为226.5℃,在氮气氛中降解起始温度508.5℃,800℃质量保持率为46.5%。共聚聚酰亚胺膜的拉伸强度、拉伸模量、断裂伸长率分别为109.7MPa、2.25GPa和15.2%。     

聚砜酰胺酸和聚砜酰亚胺的微波辐射合成

采用4，4'-二氨基二苯砜(DDS)与均苯四酸二酐(PMDA)为单体进行微波辐射溶液聚合反应，所得的聚酰胺酸进行固相微波辐射亚酰化。考察了微波辐射时间、反应温度、单体浓度、单体配比等因素对聚合物的特性粘数、转化率的影响，并与热聚合进行比较，用红外及核磁共振的测试方法对聚合物的结构进行了表征，通过红外光谱表征了聚酰亚胺的亚酰化度。实验结果表明：微波辐射不仅能缩短缩聚反应时间，还能提高缩聚物的特性粘数和转化率。固相微波辐射使聚酰胺酸的亚酰化时间缩短，亚酰化度增大。合成的聚酰胺酸和聚酰亚胺都具有一定的荧光性能，聚酰亚胺具有一定的磁性。     

Microwave-assisted synthesis of isosorbide-derived diols for the preparation of thermally stable thermoplastic polyurethane

In order to prepare thermally stable isosorbide-derived thermoplastic polyurethane, the synthesis of two new chiral exo–exo configured diols, prepared from isosorbide, and two types of diphenols (bisphenol A and thiodiphenol) was described. The synthesis conditions were optimized under conventional heating and microwave irradiations. To prove their suitability in polymerization, these monomers were successfully polymerized using 4,4′-diphenylmethane diisocyanate (MDI) and hexamethylene diisocyanate (HDI). Both monomers and polymers have been studied by NMR, FT-IR, TGA, DSC; intrinsic viscosity of polymers has also been determined. The results showed the effectiveness of the synthetic strategy proposed; moreover, a dramatic reduction of the reaction time and an important improvement of the monomers yield using microwave irradiation have been demonstrated. The monomers, as well as the polymers, showed excellent thermal stability both in air and nitrogen. It was also shown that the introduction of sulphur in the polyurethane backbone was effective in delaying the onset of degradation as well as the degradation rate.     

Polycondensation of sodium tetrazodiphenyl naphthionate and pyromellitic dianhydride under microwave irradiation and the performance of the third‐order nonlinear optics

Sodium tetrazodiphenyl naphthionate and pyromellitic dianhydride were polycondensed under microwave irradiation and oil‐bath heating. The resultant poly(amic acid) was imidized in the solid phase by microwave irradiation and oil‐bath heating. The effects of the reaction temperature, the concentration of monomers, the monomer ratio, and the microwave irradiation time on the conversion, intrinsic viscosity, and third‐order nonlinear optical (NLO) coefficient of the polymer were investigated. The results showed that the polycondensates had high third‐order NLO coefficients (χ⁽³⁾ = 1.476 × 10^?12esu) and very fast time responses (15.79 ps). The χ⁽³⁾ values of the polycondensates under microwave irradiation were higher than those of conventional thermopolymerization. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1121–1128, 2003