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1.
A new family of positive photosensitive polyimide (PPI) systems composed of solvent soluble polyimides (Pls) with cyclobutane (CBDA) structures and diazonaphthoquinone compounds (DNQ) has been prepared. Heat and catalytic imidizations were carried out to obtain CBDA Pls; the former was better than the latter in controlling the molecular weight of the Pl. The ? OH groups in the Pls were easily acetylated during catalytic imidization, so ? COOH groups were selected as weak acidic groups in the Pls. The ? COOH groups were also effective in giving the Pls an alkaline solubility. Therefore, Pls having ? COOH groups were superior to those having ? OH groups for PPI systems. The photosensitive properties of various PPl systems containing ? COOH were found to vary with the fraction of ? COOH groups in the Pls, the content of DNQ in the systems, and the molecular weight of the Pls. 相似文献
2.
I.A. Khotina L.S. Lepnev N.S. Burenkova P.M. Valetsky A.G. Vitukhnovsky 《Journal of luminescence》2004,110(4):232-238
New materials based on low-generation polyphenylene dendrimers with the light emission in the blue spectrum range were synthesized and examined for an efficient organic light emitting diodes (OLED) application. It has been shown that the ratio of p-phenylene groups with high fluorescence parameters to 1,3,5-triphenylbenzene groups with low fluorescent parameters may be the possible reason for the experimental variations of relative quantum yield of photoluminescence in the compounds explored. The quantum yield value is increased with a number of dendrimer generations up to 50–70%. The role of bromine atoms as the luminescence quenchers have been demonstrated, which is important for synthesis route choice. 相似文献
3.
Chin‐Ping Yang Ruei‐Shin Chen Kuei‐Hung Chen 《Journal of polymer science. Part A, Polymer chemistry》2003,41(7):922-938
To investigate the position and amount of the CF3 group affecting the coloration of polyimides (PIs), we prepared 2,2‐bis[4‐(4‐amino‐2‐trifluoromethylphenoxy)phenyl]hexafluoropropane ( 2 ) with four CF3 groups with 2‐chloro‐5‐nitrobenzotrifluoride and 2,2‐bis(4‐hydroxyphenol)hexafluoropropane. A series of soluble and light‐colored fluorinated PIs ( 5 ) were synthesized from 2 and various aromatic dianhydrides ( 3a – 3f ). 5a – 5f had inherent viscosities ranging from 0.80 to 1.19 dL/g and were soluble in amide polar solvents and even in less polar solvents. The glass‐transition temperatures of 5 were 221–265 °C, and the 10% weight‐loss temperatures were above 493 °C. Their films had cutoff wavelengths between 343 and 390 nm, b* values (a yellowness index) ranging from 5 to 41, dielectric constants of 2.68–3.01 (1 MHz), and moisture absorptions of 0.03–0.29 wt %. In a comparison of the PI series 6 – 8 based on 2,2‐bis[4‐(4‐aminophenoxy)phenyl]hexafluoropropane, 2,2‐bis[4‐(4‐amino‐2‐trifluoromethylphenoxy)phenyl]propane, and 2,2‐bis[4‐(4‐aminophenoxy)phenyl]propane, we found that the CF3 group close to the imide group was more effective in lowering the color; this means that CF3 of 5 , 7 , and 8f was more effective than that of 6c . The color intensity of the four PI series was lowered in the following order: 5 > 7 > 6 > 8 . The PI 5f , synthesized from diamine 2 and 4,4′‐hexafluoroisopropylidenediphthalic anhydride, had six CF3 groups in a repeated segment, so it exhibited the lightest color among the four series. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 922–938, 2003 相似文献
4.
Ajay K. Saini Clifford M. Carlin Howard H. Patterson 《Journal of polymer science. Part A, Polymer chemistry》1992,30(3):419-427
New model compounds for poly[N,N′-bis(phenoxyphenyl)pyromellitimide] have been synthesized in order to investigate the formation of imine bonds which are proposed to form during the curing process and lead to crosslinking in the bulk polymer. Raman studies show that terminal amines can react with imide carbonyls during curing to form C?N bonds. The Raman band due to C?N appears at 1656 cm?1 and the band due to C?O closest to the imine bond is observed at 1742 cm?1. These results are in agreement with previously published results on vapor deposited polyimide films. 相似文献
5.
We wish to report synthesis of perfluorinated functionalized, branched ethers from their hydrocarbon analogues by direct fluorination. Yields up to 90%, with high purities, have been obtained at ambient temperature and pressure. This technique will likely develop into a new general method for producing perfluorinated, hyperbranched and dendritic polymers. 相似文献
6.
B. Y. Myung J. S. Kim J. J. Kim T. H. Yoon 《Journal of polymer science. Part A, Polymer chemistry》2003,41(21):3361-3374
2,2‐Bis[4(4‐aminophenoxy)phenyl]phthalein‐3′,5′‐bis(trifluoromethyl)anilide (6FADAP), containing fluorine and phthalimide moieties, was synthesized via the Williamson ether condensation reaction from 1‐chloro‐4‐nitrobenzene and phenolphthalein‐3′,5′‐bis(trifluoromethyl)anilide, which was followed by hydrogenation. Monomers such as 2,2‐bis[4(4‐aminophenoxy)phenyl]phthalein‐anilide containing phthalimide groups and 2,2‐bis[4(4‐aminophenoxy)phenyl]phthalein containing only phthalein moieties were also synthesized for comparison. The monomers were first characterized by Fourier transform infrared (FTIR), 1H NMR, 19F NMR, elemental analysis, and titration and were then used to prepare polyimides with 2,2‐bis(3,4‐dicarboxyphenyl)hexafluoropropane dianhydride. The polyimides were designed to have molecular weights of 20,000 g/mol via off‐stoichiometry and were characterized by FTIR, NMR, gel permeation chromatography (GPC), differential scanning calorimetry, and thermogravimetric analysis. Their solubility, water absorption, dielectric constant, and refractive index were also evaluated. The polyimides prepared with 6FADAP, containing fluorine and phthalimide moieties, had excellent solubility in N‐methylpyrrolidinone, N,N‐dimethylacetamide, tetrahydrofuran, CHCl3, tetrachloroethane, and acetone, and GPC analysis showed a molecular weight of 18,700 g/mol. The polyimides also exhibited a high glass‐transition temperature (290 °C), good thermal stability (~500 °C in air), low water absorption (1.9 wt %), a low dielectric constant (2.81), a low refractive index, and low birefringence (0.0041). © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3361–3374, 2003 相似文献
7.
Jin Kyu Park Dong Hun Lee Bok Ju Song Jae Buem Oh Hwan Kyu Kim 《Journal of polymer science. Part A, Polymer chemistry》2006,44(3):1326-1342
We have designed and synthesized novel perfluorinated polyimides with 3D controlled structure. At first, we successfully developed the new synthetic routes to diamines with pendant bulky perfluorinated aromatic units in a multi‐step synthetic procedure. Novel perfluorinated polyimides were prepared in a two‐step reaction in N‐methyl‐2‐pyrrolidinone (NMP) solution: The first step was for the synthesis of polyamic acids (PAAs) and the second reaction was for the imidization of PAA. The polymer yield was over 89% and the inherent viscosity of PAAs was in the range of 0.24–0.36 dL/g. The thin films were prepared by spin‐coating the PAA solution in NMP onto various substrates such as a Si wafer or a KBr pellet, dried at 80 °C and further cured at 230 °C. The resultant polyimides are thermally stable over 400 °C. The refractive index and birefringence of the resultant polyimides are 1.5858–1.6452 and 0.01–0.005, respectively. The refractive index of polyimide decreases with increasing the fluorine content. The copolymerization and the ether linkages into the backbone reduce the birefringence of polyimides. Surprisingly, the pendant ether linkage is not a crucial factor in reducing the polyimide birefringence. Their birefringence is comparatively very low, compared with that of previous polyimides. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1326–1342, 2006 相似文献
8.
Katsuya Sakayori Yuji Shibasaki Mitsuru Ueda 《Journal of polymer science. Part A, Polymer chemistry》2006,44(21):6385-6393
Poly(amic acid)s (PAAs) having the high solution stability and transmittance at 365 nm for photosensitive polyimides have been developed. PAAs with a twisted conformation in the main chains were prepared from 2,2′,6,6′‐biphenyltetracarboxylic dianhydride (2,2′,6,6′‐BPDA) and aromatic diamines. Imidization of PAAs was achieved by chemical treatment using trifluoroacetic anhydride. Among them, the PAA derived from 2,2′,6,6′‐BPDA and 4,4′‐(1,3‐phenylenedioxy)dianiline was converted to the polyimide by thermal treatment. The heating at 300 °C under nitrogen did not complete thermal imidization of PAAs having glass‐transition temperatures (Tg)s higher than 300 °C to the corresponding PIs. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6385–6393, 2006 相似文献
9.
用裂解气相色谱法研究PMR型聚酰亚胺前体在反应中的化学变化过程,以裂解产物醇和环戊二烯的生成率表示酰胺化或酰亚胺化及交联的程度,结果表明,酰胺化或酰亚胺化在50℃以下不发生,在180~220℃完成,降冰片烯端基在150℃以下不发生交联反应,在280℃,10~18小时可完成交联反应。 相似文献
10.
用ATRP法构筑核壳型梯度极性的多羟基多臂星状超支化聚合物及聚合物刷——双层聚合物刷的合成与表征 总被引:3,自引:0,他引:3
设计并通过原子转移自由基聚合方法 (ATRP)合成了核壳型多羟基多臂星状超支化聚合物刷 .以 2 溴异丁基酰溴封端的超支化聚 (3 乙基 3 羟甲基氧杂环丁烷 ) (HP Br)作为大分子引发剂 ,采用Cu(I)Br和N ,N ,N′ ,N′ ,N″ 五甲基二乙基三胺 (PMDETA)催化体系 ,在丁酮与丙醇的混和溶液中 ,通过甲基丙烯酸羟乙酯(HEMA)的ATRP溶液聚合 ,得到了一系列含有大量羟基的多臂星状超支化聚合物刷 (HP g PHEMA) ,并考察了其羟基的活性 ,发现羟基还可以与苯甲酰氯发生反应 .产物的结构和热性能用1 H NMR、FTIR、GPC、TGA、DSC等进行了表征和测试 . 相似文献