ORGANO-SOLUBLE FLUORINATED POLYIMIDES DERIVED FROM α,α-BIS(4-AMINO-3,5-DIMETHYLPHENYL)-4'-FLUOROPHENYL METHANE AND VARIOUS AROMATIC DIANHYDRIDES

Organo-soluble fluorinated polyimides were synthesized by the polycondensation of a new aromatic diamine α,α-bis(4-amino-3,5-dimethylphenyl)-4'-fluorophenyl methane with several aromatic dianhydrides.The one-step polymerizationprocedure was conducted at 180℃ in m-cresol,producing the polyimides with inherent viscosities of 0.68-0.76 dL.g^(-1).Thepolyimides could be soluble not only in polar aprotic solvents,such as N-methyl-2-pyrrolidinone,and N,N-dimethylacetamide,but also in common organic solvents,such as chloroform,cyclopentanone,m-cresol and so on.Thepolyimide films show excellent transparency with the UV-Vis cut-off lengths of 310-360 nm and light transmittances ofhigher than 80% in the visible region.In addition,the polyimides exhibit good thermal stability with an initial decompositiontemperature(T_d)higher than 530℃ and have more than 60% of residual weight retentions at 700℃.

Synthesis and Characterization of Novel Polyimides Based on Pyridine-containing Diamine

A new aromatic diamine monomer containing pyridine unit, 2,6-bis （4-aminophenoxy- 4＇-benzoyl）pyridine（BABP）, was synthesized in three steps, starting from 2,6-pyridinedicarboxyl chloride. A series of novel pyridine-containing polyimides were prepared v/a the polycondensation of BABP with various aromatic dianhydrides through poly（amic acid） precursors, and thermal or chemical imidization of the precursors. The polyimides exhibit desirable properties, e.g., good solubility in N-methyl-2-pyrrolidone and m-cresol, excellent thermal stability and film-forming capability, as well as high inherent viscosity, indicating high molecular weight.

FLUORINATED PHTHALAZINONE-CONTAINING COPOLYIMIDES FOR PASSIVE OPTICAL WAVEGUIDES

A series of fluorinated copolyimides containing phthalazinone moieties were prepared from 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride(6FDA),3,3'4,4'-benzophenone-tetracarboxylic dianhydride(BPDA)and2-(4-aminophenyl)-4-[4-(4-aminophenoxyl)phenyl]-2,3-phthalazin-1-one(DHPZ-2NH_2)for making polymeric opticalwaveguides.The resulting copolymers containing 0-50 mo1% BPDA/DHPZ-2NH_2 show good solubility and are soluble insome organic polar aprotic solvents.The copolyimides also present excellent thermal stability.These polymers possess highglass transition temperature higher than 603 K and high decomposition temperature above 742 K determined by differentialscanning calorimetry and thennogravimetric analysis,respectively,under a nitrogen atmosphere.Their refractive indicescould be controlled by varying the ratio of 6FDA and BPDA in the copolymer from 0.5 to 1.0,and the in-plane refractiveindices(n_(TE))range from 1.6366 to 1.6668 and the out-of-plane refractive indices(n_(TM))from 1.6024 to 1.6280 at 632.8 nm.The polymers birefringence(0.0342-0.0388)is almost independent of the 6FDA content of copolymer,which indicated thatthe phthalazinone-containing copolyimides could be suitable to fabricate optical waveguides possessing a low polarizationdependent loss(PDL).

SYNTHESIS AND CHARACTERIZATION OF ORGANO-SOLUBLE FLUORINATED POLYIMIDES FROM 4,4'-BIS(3-AMINO-5-TRIFLUOROMETHYLPHENOXY)-BIPHENYL AND VARIOUS AROMATIC DIANHYDRIDES

An aromatic diamine monomer,4,4'-bis(3-amino-5-trifluoromethyl phenoxy)-biphenyl (TFBPDA),wassynthesized via the nucleophilic displacement reaction of 3,5-dinitrobenzotrifluoride and 4,4'-biphenol.The monomer wasreacted with various aromatic dianhydrides via the high temperature polycondensation procedure to provide a series ofpolyimides.The polyimides,PI-1 to PI-4,show good solubility not only in aprotic solvents,such as N-methyl-2-pyrrolidinone and N,N-dimethylacetamide,but also in many common solvents,such as m-cresol,chloroform andcyclopentanone.PI-4,derived from 4,4'-(hexafluoroisopropylidene)diphthalic anhydride and TFBPDA,was even soluble intoluene.Moreover,PI films exhibit good thermal stability,outstanding transparency in the visible light region and acceptablemechanical and electrical properties.The excellent combined properties of the polyimides make them as a good candidate forfabricating microelectronics.

Synthesis and Properties of New Fluorinated Polyimides Derived from an Unsymmetrical and Noncoplanar Diamine

A new unsymmetrical and noncoplanar diamine containing trifluoromethyl and trimethyl groups, 1,4-bis（4- amino-2-trifluoromethylphenoxy）-2,3,5-trimethylbenzene （2）, was synthesized using 2,3,5-trimethylhydroquinone and 2-chloro-5-nitrobenzotrifluoride as starting materials. A series of fluorinated poly（ether imide）s （PEIs） （4a-4d） were prepared from diamine 2 with four aromatic dianhydrides via a one-step high-temperature polycondensation procedure. The obtained PEIs were readily soluble in most organic solvents and could be solution-cast into flexible and strong films. The resulting thin films exhibited light color and good optical transparency with a cutoff wave- length of 356--376 nm. They also displayed good thermal stability with glass transition temperatures （Tg） above 281℃, 10% weight loss temperatures in the range of 482--486 ~C, and the weight residue more than 55% at 800℃ in nitrogen. Moreover, they revealed low dielectric constants （2.77-2.93 at 1 MHz） and low moisture absorp- tions （0.41%-0.57%）.

Fluorinated Colorless Polyimides with High Heat-resistance and Low Birefringence

The development of optical films with high transparency,high thermal resistance and low birefringence remains a challenge in the flexible display industry.In this work,we designed and synthesized a series of fluorinated colorless polyimides(CPIs)materials using 2,5-substituted m-phenylenediamine diamine monomers and 1,2,4,5-cyclohexanetetracarboxylic dianhydride(CHDA).We systematically studied the effects of fluorinated group substitutions on the thermal,mechanical,optical and dielectric properties of CPI films.The introduction of alicyclic CHDA dianhydride affords high transparency and low yellowness,while the 2,5-substituted m-phenylenediamine diamines offer the CPIs with quite low birefringence as well as high glass transition temperatures.A particular CHDA/o3FBDA film with simple chemical structure stands out,exhibiting well-balanced overall properties.

Polyimides Based on Flexible Diamines:Synthesis, Characterization and Thermal Properties

1 Results and DiscussionTwo diamines 1,4-phenylene di(oxy-4,4′-aniline) and 4-aminophenyloxy-N-4-[(4-amiophenyloxy)benzylidene]aniline were prepared via the nucleopilic substitution reaction and were polymerized with 3,3′,4,4′-benzophenonetetracarboxylic acid dianhydride (BP), 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (HF) , 3,4,9,10-perylenetetracarboxylic acid dianhydride (PD) and pyromellitic dianhydride (PMDA) either by one step solution polymerization reaction or two step procedure. The l...

Asymmetric Synthesis of Fluorinated Vicinal Diamines from Fluoromethyl Sulfinyl Imines and Diphenylmethylene-Benzylamines

A novel strategy was developed for the asymmetric synthesis of fluorinated vicinal diamines.Deprotonation of N-(diphenylmethylene)-benzylamines under base,followed by asymmetric nucleophilic addition to N-tert-butanesulfinylfluoroacetaldimines,a pair of diastereomeric isomers were afforded.The diastereomeric isomers can be easily separated from each other by silica gel column chromatography.The absolute steric configuration of two isomers was confirmed by single crystal X-ray diffraction analyses.The proposed mechanism revealed that the configuration of the carbon next to tert-butanesulfinyl was well controlled to be R by the chiral auxiliary.

脂环二胺浅色透明聚酰亚胺薄膜的制备及性能表征

采用二步法,在冰浴的条件下,以含脂环结构的二胺单体5-氨基-1,3,3-三甲基环己甲胺(IPDA)和4,4′-二氨基二环己基甲烷(PACM)与二酐单体4,4′-(4,4′-异丙基二苯氧基)双(邻苯二甲酸酐)(BPADA),制备六种不同二胺比例的聚酰亚胺(PI)薄膜。通过红外光谱、X射线衍射(XRD)分析、紫外可见光谱、热机械分析、差示扫描量热(DSC)测试、热失重测试和力学性能测试对薄膜进行表征分析。结果表明,PI薄膜已经完全亚胺化,整体为无定型形态,在可见光范围内具有较高的紫外透过率,最大透过率均在87%以上,450 nm最高透过率为83.26%,力学性能表现出柔性,玻璃化转变温度(Tg)均在200℃左右,初始分解温度均在388℃以上,在未到初始分解温度之前,几乎不发生质量损失,热稳定性良好。

New Soluble Polyimides with High Optical Transparency and Light Color Containing Pendant Trifluoromethyl and Methyl Groups

A new aromatic diamine containing trifluoromethyl and methyl groups, namely a,a-bis（4-amino-3-methylphetayl）-4-（trifluoromethyl）phenylmethane （1）, was synthesized from 2-methylaniline and 4-（trifluoromethyl）- benzaldehyde. A series of fluorinated polyimides （PIs） were prepared from the diamine with four commercially available aromatic tetracarboxylic dianhydrides using a one-step high-temperature polycondensation procedure. These obtained PIs showed excellent solubility, with the dissolvability at a concentration of 10 wt% in most solvents, and they could afford flexible and strong films. Thin films of these PIs exhibited high optical transparency and light color, with the cutoff wavelength at 324-357 nm and transmittance higher than 74% at 450 nm. Moreover, these Pls possessed eminent thermal stability and good mechanical properties.

Fluorine Substitution Effect on the Material Properties in Transparent Aromatic Polyimides

The recent development of flexible display technology raised additional requirements for optical and electric properties of polyimides,accelerating the structure and property tunning of transparent polyimides.The unique electronic effect and steric hindrance effect of fluorine substitutions make fluorine-containing polyimides occupy an important position in the transparent polyimide family.In this work,a series of transparent aromatic polyimides were prepared from a fixed 4,4’-(hexafluoroisopropylidene)diphthalic anhydride(6FDA)and biphenyl diamines with different substitute groups at the 2,2’,6,6’-positions.We systematically studied the effects of pendant groups on the thermal,mechanical,optical and dielectric properties of these 6FDA-based polyimides with the aid of density function theory(DFT)calculation.In particular,we paid special attention to the simple but compact fluoro group substitution.The simple fluoro substitution brought the advantages of maintaining the linearity of the backbone and dense polymer chain packing,which would minimize the weakening of polyimides’inherent thermal,dimensional and mechanical properties.Comparing with trifluoromethyl substituted polyimides with the best optical transparency,polyimides containing fluoro substitutes exhibited slightly decreased optical transparency,but increased thermal and dimensional stability and higher mechanical strength.These results could shed light on the ultimate transparent polyimide film development toward the application in extreme working condition,e.g.,the colorless polyimide substrate film for the flexible display technology.

Synthesis of a new pyridine-containing diamine and related polyimide

A new kind of aromatic diamine monomer containing pyridine unit,2,6-bis[4-(4-aminophenoxy)phenoxy]pyridine(BAPP),was synthesized in three steps,using hydroquinone as starting material.A novel pyridine-containing polyimide was prepared from the resulting diamine BAPP with 4,4 -oxydiphthalic anhydride(ODPA) via a conventional two-step thermal imidization method.The resulting polyimide exhibits excellent solubility,film-forming capability and high thermal resistance.

Synthesis of a New Asymmetrical Ether Diamine with Aromatic Structure and Related Polyimide

A new aromatic asymmetrical ether diamine, 1,4-bis（3＇,4’-diaminophenoxy）benzene 3 was synthesized in three steps, using hydroquinone as starting material. A new aromatic polyimide containing asymmetrical diaryl ether segments was prepared from the resulting diamine with 4,4＇-oxydiphthalic anhydride （ODPA） via a conventional two-step thermal or chemical imidization method. The resulting polyimide exhibits high thermal resistance, excellent solubility, film-forming capability, high mechanical strength and modulus.

Synthesis of anew siloxane-containing diamine and related polyimide

A novel siloxane-containing diamine, bis[4-(p-aminophenoxy)phenoxy]dimethylsilane (APPMS), was successfully synthesized in three steps using hydroquinone as starting material, which was reacted with 4,4′-oxydiphthalic anhydride (ODPA) via a conventional two-step thermal or chemical imidization method to produce a new siloxane-containing polyimide. The resulting polyimide exhibited excellent solubility, and film-forming capability.

Design of Polarization-independent Wavelength-interleave Coupler in Fluorinated Polyimide Waveguide

Based on the measurement of dispersion characteristic and birefractive index of the fluorinated polyimide film,a statistical optimum design method is proposed and used to realize the design of 32- and 36-wavelengths optical waveguide wavelength-interleave coupler(i,e.,interleaver) with the optimization of polarization fluctuation and wavelength interval of 0.8 nm at 1 550 nm.The largest cross coupling ratios of the two interleavers are respectively less than 1.8% and 3.5%,while the least through coupling ratios are respectively greater than 98.2% and 96.5%.The output differences due to polarization fluctuation are less than ±1.7% and ±3.2%.

Synthesis of nonlinear optical fluorinated polyimide/inorganic composites for photonic devices

A nonlinear optical (NLO) active alkoxysilane chromophore (SGDR1) was synthesized. A fluorinated polyimide/SGDR1 composite was prepared to improve the poor temporal stability of second-order NLO effects of the reported poled sol-gel film. The poled composite film was characterized by FTIR, DSC, TGA and UV-Vis. The composite displays good hydrophobic properties, high glass transition temperature (266 ℃), and high decomposition temperature (433 ℃). The second harmonic coefficient d33 of the composite was measured to be 16.77 pm/V by using maker fringe technique. The new NLO composite exhibits 85 % of the original d33 over 720 h at 100 ℃ and possesses much better stability than the reported sol-gel film.

一种含氟类聚酰亚胺的合成与表征综合实验设计

主要针对辽宁科技大学应用化学专业实验项目设计了含氟类聚酰亚胺的合成与表征的综合设计性实验。通过实验设计了含氟芴基二胺9,9-双(4-氨基-2-三氟甲基苯氧基苯基)芴的方法,再加入不同比例不同种类的三胺,与CBDA聚合生成聚酰胺酸溶液,涂膜、热酰胺化得到含氟的聚酰亚胺薄膜,并通过红外、DSC、拉伸强度、透光率来对聚酰亚胺薄膜进行表征。添加含氟基团可以提高聚酰亚胺的性能,使其有更广阔的应用。

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%。

氟化石墨烯绝缘导热性能及其聚酰亚胺复合材料性能研究进展

便携式电子设备的发展对于高导热和电绝缘的热管理材料需求越来越大,氟化石墨烯(FG)作为一种新兴的具有高热导率及电绝缘性的导热填料受到了科学界的广泛关注。本文总结了FG的制备方法、结构与性能关系等,特别对FG的导热机理进行了分析,同时系统阐述了FG作为功能填料复合改性聚酰亚胺(PI)的最新研究进展,并对存在的问题和挑战进行了总结和展望。

含氟PI/氟化石墨烯复合薄膜的制备与性能

为了降低聚酰亚胺(PI)薄膜的介电常数及介电损耗,使其满足如5G通信等领域的应用需求,在合成本征型含氟聚酰亚胺(FPI)的基础上引入氟化石墨烯(FG)填料制备了高含氟量PI薄膜。首先采用溶剂热插层辅助超声离心的方法制备了FG填料,利用傅里叶变换红外光谱仪、激光粒度分布仪及X射线衍射仪对制备的FG进行表征,再利用原位聚合法合成了本征型FPI/FG复合薄膜,并对复合薄膜的微观形貌、介电性能、力学性能及耐水性能进行测试,研究不同FG含量对复合薄膜结构与性能的影响。结果表明,成功制备了粒径较小的FG纳米填料和FPI/FG复合薄膜,将FG加入到FPI基体中能有效降低其介电常数,随着FG填料在复合薄膜中质量分数的增大,FPI/FG复合薄膜的介电常数呈现先降低后升高的趋势,当FG质量分数为1.0%时,薄膜具有最低的介电常数2.11及较低的介电损耗(<0.015)。此外由于FG与FPI间较好的相互作用,使得FPI/FG复合薄膜的拉伸性能和耐水性得到一定改善。