共查询到20条相似文献,搜索用时 15 毫秒
1.
Mitsuru Ueda Takeyoshi Takahashi Yoshio Imai 《Journal of polymer science. Part A, Polymer chemistry》1976,14(3):591-602
A new class of polyheterocycles, polybenzodipyrrolediones (PBP), has been synthesized successfully by the two-step polymerization of dibenzylidenebenzodifurandiones with aliphatic diamines. New bislactone monomers, 3,5-dibenzylidene-3,5-dihydro-1H,7H-benzo[1,2-c:4,5-c′]difuran-1,7-dione and 3,7-dibenzylidene-3,7-dihydro-1H,5H-benzo[1,2-c:4,5-c′]-difuran-1,5-dione, were synthesized from pyromellitic dianhydride and phenylacetic acid. The ring-opening polyaddition reaction of the bislactones with aliphatic diamines in a polar solvent afforded novel polyamides having inherent viscosities of 0.1–1.0 in quantitative yield. The solution polymerization was almost completed within several hours at 80°C, while it required approximately a week to its completion at room temperature. Dimethyl sulfoxide and N-methyl-2-pyrrolidone were preferred solvents for the polymerization. The open-chain polyamides were subsequently cyclodehydrated by heating at 240°C to give PBP having high molecular weight. The aliphatic PBP were soluble in hot polar solvents such as N-methyl-2-pyrrolidone, m-cresol, and nitrobenzene. They began to decompose at about 400°C in a nitrogen atmosphere as determined by thermogravimetric analysis. 相似文献
2.
Mitsuru Ueda Takeyoshi Takahashi Yoshio Imai 《Journal of polymer science. Part A, Polymer chemistry》1978,16(7):1735-1745
Novel diacetylphthalic acids, 2,5-diacetylterephthalic and 4,6-diacetylisophthalic acids, were synthesized starting from pyromellitic dianhydride. These diacids were subsequently converted to the corresponding pseudo diacetylphthaloyl chlorides. The ring-opening polyaddition, followed by dehydrochlorination, of the pseudo diacetylphthaloyl chlorides with aliphatic diamines in a polar aprotic solvent afforded almost quantitatively polyamides having inherent viscosities of 0.3–0.7. The solution polymerization was almost completed within 1 hr at room temperature. These polyamides were soluble in acidic solvents like m-cresol. Subsequent cyclodehydration of the polyamides by heating at 200°C gave insoluble polybenzodipyrrolediones, which underwent weight losses of 10% at around 400°C under nitrogen. 相似文献
3.
Chin-Ping Yang Yoshiyuki Oishi Masa-Aki Kakimoto Yoshio Imai 《Journal of polymer science. Part A, Polymer chemistry》1989,27(12):3895-3901
Aromatic polyamides (aramids) having pendant t-butyl group were synthesized by the direct polycondensation of 5-t-butylisophthalic acid with various aromatic diamines in N-methyl-2-pyrrolidone (NMP) using triphenyl phosphite and pyridine as condensing agents. The aramids having inherent viscosities of 0.6–2.4 dL/g were obtained in quantitative yields. These polymers were readily soluble in various solvents such as NMP,N,N-dimethylacetamide, dimethyl sulfoxide, and pyridine, and gave transparent, tough and flexible films by casting from the NMP solutions. The aramids had glass transition temperatures between 250 and 330°C, and started to lose weight around 350°C, with 10% weight loss being recorded at about 450°C in air. 相似文献
4.
Wu C Wang J Chang P Cheng H Yu Y Wu Z Dong D Zhao F 《Physical chemistry chemical physics : PCCP》2012,14(2):464-468
Polyureas were synthesized from diamines and carbon dioxide in the absence of any catalyst or solvent, analogous to the synthesis of urea from condensation of ammonia with carbon dioxide. The method used carbon dioxide as a carbonyl source to substitute highly toxic isocyanates for the synthesis of polyureas. FTIR and DFT calculations confirmed that strong bidentate hydrogen bonds were formed between urea motifs, and XRD patterns showed that the PUas were highly crystalline and formed a network structure through hydrogen bonds, which served as physical cross-links. The long chain PUas presented a microphase separated morphology as characterized by SAXS and showed a high melting temperature above 200 °C. The PUas showed high resistance to solvents and excellent thermal stability, which benefitted from their special network structures. The PUas synthesized by this method are a new kind of functional material and could serve some areas where their analogues with similar functional groups could not be applied. 相似文献
5.
We report a direct synthesis of polyamides via catalytic dehydrogenation of diols and diamines. A PNN pincer ruthenium complex, the Milstein catalyst, was used for this reaction and polyamides with number average molecular weight from ~10 to 30 kDa could be obtained from a wide variety of diols and diamines bearing aliphatic or aromatic, linear or cyclic spacers. Because of the high catalytic selectivity of primary amine over secondary amine, polyamines could be conveniently incorporated into linear polyamides without tedious protection/deprotection steps. Compared with conventional condensation method, this catalytic system avoids the requirement of stoichiometric preactivation or in situ activation reagents and provides a much cleaner process with high atomic economy. 相似文献
6.
Qianqian BuShujiang Zhang Hui LiYanfeng Li Chenliang GongFengchun Yang 《Polymer Degradation and Stability》2011,96(10):1911-1918
A novel method for the preparation of an asymmetric fluorinated aromatic diamine, 3,4′-bis(4-amino-2-trifluoromethylphenoxy)-benzophenone was investigated. This new diamine containing trifluoromethyl side group was synthesized from the nucleophilic substitution reaction of 2-chloro-5-nitrobenzotrifluoride and 3,4′-dihydroxybenzo phenone in the presence of potassium carbonate, followed by catalytic reduction with SnCl2·6H2O and concentrated hydrochloric acid. This novel diamine was used to react with different commercially available aromatic tetracarboxylic dianhydrides to prepare polyimides via thermal or chemical imidization. The polyimide properties such as inherent viscosity, solubility, thermal and surface properties were investigated to illustrate the contribution of the trifluoromethyl group and the asymmetry structure of the polyimide. The polyimides obtained had good thermal stability and the glass transition temperature values ranged from 225 to 267 °C. All of these novel polyimides held 10% weight loss at the temperature above 543 °C in air and left more than 47% residue even at 800 °C in nitrogen. The inherent viscosities of the obtained polyimides were above 0.73 dL/g and were easily dissolved in both polar, aprotic solvents and some low-boiling-point solvents. Moreover, these PI films had dielectric constants of 2.94-3.53 (1 kHz), with moisture absorption in the range of 0.07-0.34 wt%. In comparison of the PIs (5) series with the analogous symmetric PIs (6) series based on 4,4′-bis(4-amino-2-trifluoromethylphenoxy)-benzophenone, the (5) series revealed better solubility, low dielectric constant and moisture absorption. 相似文献
7.
Synthesis of benzylidene-pendant polyphthalimidines from flexible bisphthalides and various diamines
Yoshio Imai Takeyoshi Takahashi Renzhi Nan Mitsuru Ueda 《Journal of polymer science. Part A, Polymer chemistry》1983,21(5):1241-1249
New polyphthalimidine-forming monomers, 5,5′-(oxydi-p-phenylenedicarbonyl)bis(3-benzylidenephthalide) and the 6,6′-derivative, were synthesized by the Friedel–Crafts reaction of diphenyl ether with 5- and 6-chloroformyl-3-benzylidenephthalide, respectively. The direct polycondensation of these bisphthalides with both aliphatic and aromatic diamines in o-phenylphenol at 200–250°C afforded polyphthalimidines having inherent viscosities of 0.2–1.2 dL/g in almost quantitative yields. Syntheses of aliphatic polyphthalimidines with higher inherent viscosities were also achieved by a two-step procedure involving ring-opening polyaddition and subsequent thermal cyclodehydration. All the polymers were amorphous and readily soluble in N-methyl-2-pyrrolidone (NMP), m-cresol, nitrobenzene, pyridine, and chloroform. Tough and flexible films could be cast from NMP solutions of the polymers. Glass transition temperatures of the polyphthalimidines were in the range of 158–246°C. The thermogravimetry of the aromatic polymers showed 10% weight loss in air and nitrogen at 445–515 and 500–520°C, respectively. The crosslinking reaction of some benzylidenependant polyphthalimidines took place at 300°C through double-bond addition to afford cured polymers with improved thermal stability. 相似文献
8.
9.
Ke Xu Zhao Ke Dongpeng Li Tao Li Guangtao Qian Zhiqing Deng Dandan Li Youhai Yu 《Journal of polymer science. Part A, Polymer chemistry》2024,62(9):1808-1819
To synthesize colorless superheat-resistant polyimide films, one of the valid approaches is the incorporation of the asymmetric and warped structures in the main chain. Applying this approach on 5(6)-amino-2-(4-aminobenzene)benzimidazole (PABZ) and changing its linearity, 6, 5′-diamine-2′-methyl-1-methyl-2-phenylbenzimidazole (5a) and 6, 3′-diamine-2′-methyl-1-methyl-2-phenylbenzimidazole (5b) were devised and synthesized successfully, then polymerized with 1,2,4,5-cyclohexanetetracarboxylic dianhydride (HPMDA). The prepared poly(benzimidazole imide)s (PBIIs) with the rigid main chain and loose packing had the excellent heat-resistant level (Tg > 400°C) and optical properties (T400 > 80%). Besides, the alterations resulting from various linearities were discussed comprehensively. This research is beneficial to the application of optical field, providing a promising candidate of heat-resistant colorless materials. 相似文献
10.
A new and rather widely applicable method for the synthesis of a number of tri, tetra-, and pentacyclic compounds from ortho-aminodiacylarylimides and dibromotriphenylphosphorane via an intramolecular cyclization is reported. A mechanism for this cyclization is proposed. 相似文献
11.
A convenient one-step synthesis of five-membered or six-membered imino-protected cyclic guanidine via an intramolecular ring-closure reaction of alkyl diamine(2a-2g) with 1,3-diamino-protected methylisothiourea(1a and 1b) was established and investigated.Amino guanidine such as 3-(2-aminoethyl)-1,2-dibenzyloxycarbonylguanidine(4a) has been proved to be the intermediate of the reaction via utilizing mono-protected diamine as starting material.The intramolecular ring closure of 4a results in 2-benzyloxycarbonyliminoimidazolidine(3a).This new one-step synthesis has advantages of simple condition,easy workup procedure and reasonable yield. 相似文献
12.
Synthesis and characterization of novel polyimides derived from pyridine-bridged aromatic dianhydride and various diamines 总被引:2,自引:0,他引:2
A new kind of pyridine-bridged aromatic dianhydride monomer, 4-phenyl-2,6-bis[4-(3,4-dicarboxyphenoxy)phenyl]-pyridine dianhydride (PPDA), was successfully synthesized by modified Chichibabin reaction of benzaldehyde and substituted acetophenone, 4-(3,4-dicyanophenoxy)-acetophenone (DCAP), followed by acidic hydrolysis of the intermediate tetranitrile and cyclodehydration of the resulting tetraacid. The pyridine-bridged aromatic dianhydride was employed to synthesized a series of new pyridine-containing polyimides by polycondensation with various aromatic diamines in N-methyl-2-pyrrolidone (NMP) via the conventional two-step method, i.e. ring-opening polycondensation forming the poly(amic acid)s and further thermal or chemical imidization forming polyimides. The inherent viscosities of the resulting polyimides were in the range of 0.49-0.63 dL/g, and most of them were soluble in aprotic amide solvents and cresols, such as N,N-dimethylacetamide (DMAc), NMP, and m-cresol, etc. Meanwhile, strong and flexible polyimide films were obtained, which have good thermal stability with the glass transition temperatures (Tg) of 223-256 °C, the temperature at 5% weight loss of 523-569 °C, and the residue at 700 °C of 52.1-62.7% in nitrogen, as well as have outstanding mechanical properties with the tensile strengths of 70.7-97.6 MPa and elongations at breakage of 7.9-9.7%. Wide-angle X-ray diffraction measurements revealed that these polyimides were predominantly amorphous. 相似文献
13.
Yu. N. Lazareva M. N. Vidyakin A. Yu. Alentiev M. Yu. Yablokova A. A. Kuznetsov I. A. Ronova 《Polymer Science Series A》2009,51(10):1068-1074
Gas-separating membrane characteristics of polyimide films composed of the common fragment of benzophenone-3,3′,4,4′-tetracarboxylic
dianhydride and diamines of varying structure were studied. Permeability coefficient P, diffusion coefficient D, and solubility coefficient S for H2, CO, CO2, and CH4 were determined. The polyimide derived from m-phenylenediamine exhibited the best gas-separating properties. A relationship between the chain rigidity, free volume, and
transport parameters (P, D, S, and selectivity) of polyimide was established on the basis of the data. It was shown that there is an optimal chain rigidity
for the studied polyimides that results in polymer structurization during film preparation and corresponds to high separation
selectivity. 相似文献
14.
Meenakshi Goyal Tatsuo Inoue Masa-Aki Kakimoto Yoshio Imai 《Journal of polymer science. Part A, Polymer chemistry》1998,36(1):39-47
Aliphatic polyimides (P-XBTA) having inherent viscosities of 0.4–1.4 dL/g were readily synthesized by the high-pressure polycondensation of the salt monomers, composed of aliphatic diamines having various methylene chain lengths (X = 4–12) and 3,3′,4,4′-benzophenonetetracarboxylic acid (BTA), under 200–250 MPa at 200–320°C. The salt monomers with odd-numbered methylene units were found to be more susceptible to crosslinking than those containing even-numbered methylene chains. The polyimides having even-numbered methylene units were highly crystalline, whereas those with odd-numbered methylene chains were crosslinked and therefore amorphous with only one exception, i.e., P-11BTA. The thermal behavior of these polymers was also studied. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 39–47, 1998 相似文献
15.
S. V. Kononova E. V. Kruchinina K. A. Romashkova I. L. Potokin A. V. Shchukarev V. V. Kudryavtsev 《Russian Journal of General Chemistry》2010,80(10):1977-1985
Morphology of microporous films prepared from aromatic polyamidoimides under different molding conditions was studied by scanning,
transmission, and atomic force microscopy with the specific attention given to the nanosize skin layer. The films were manufactured
by the phase inversion molding of aromatic polyamidoimides which were synthesized by low-temperature polycondensation of phthalimidobenzenedicarbonyl
dichloride with various diamines. Comparison of the parameters of films, including their wettability and X-ray photoelectron
spectroscopy data, gave additional information on factors affecting the mechanism of formation of microporous membranes in
the system polymer (polyamidoimide)-solvent (N-methylpyrrolidin-2-one)-non-solvent (water). 相似文献
16.
Yoshiyuki Oishi Shigeyuki Harada Masa-Aki Kamimoto Yoshio Imai 《Journal of polymer science. Part A, Polymer chemistry》1989,27(10):3393-3403
New fluorine-containing aromatic polyamides with inherent viscosities of 0.4–1.8 dL/g were prepared by the low temperature solution polycondensation of tetrafluoroisophthaloyl and tetrafluoroterephthaloyl chlorides with N,N′-bis(trimethylsilyl)-substituted aromatic diamines. The aromatic polyperfluoroisophthalamides were amorphous polymers with glass transition temperatures around 280°C, whereas the polyperfluoroterephthalamides were crystalline. Most of these aromatic polyamides were soluble in organic solvents, and began to decompose around 330°C in air or nitrogen atmosphere. 相似文献
17.
C. G. Overberger T. Nishiyama 《Journal of polymer science. Part A, Polymer chemistry》1981,19(2):331-348
The polyamides were prepared from the dicarbonyl chloride of (+) (S)- or (?)(R)-trans-1,2-cyclopropanedicarboxylic acid (C3A) with either the dihydrochloride salt of (+)(S)- or (?)(R)-trans-1,2-diaminocyclopropane (C3B) or the dihydrobromide salt of (+)(S)- or (?)(R)-trans-1,2-bis(methylamino)cyclopropane (C3MB) by interfacial polycondensation. Several diamide model compounds composed of these monomers were also synthesized. The polyamides [poly(C3A-C3B)] derived from C3A and C3B have the capability of hydrogen bonding, while the polyamides [poly-(C3A-C3MB)] derived from C3A and C3MB do not. Poly(C3A-C3B) were insoluble in common organic solvents except strong acids. Poly(C3A-C3MB) were soluble in common organic solvents. Poly(C3A-C3B) had melting points higher than 300°C. Poly(C3A-C3MB) melted at 180–235°C. The ORD and CD study has shown that poly(+)C3A(+)C3B in methane sulfonic acid (MSA), 2,2,2-trifluoroethanol (TFE) (5 v % MSA), and tetramethylenesulfone (TMS) (5 v % MSA) exhibits a very strong Cotton effect or CD peak at 212–218 mμ, attributable to a component of the split π–π* transition of the amide chromophores. Poly(+)C3A(+)C3MB in MSA and TFE (5 v % MSA) shows a strong Cotton effect or CD peak at 217–223 mμ and an intermediate Cotton effect or CD trough at 202–204 mμ as well as an intermediate Cotton effect or CD trough at 220–222 mμ and an intermediate Cotton effect or CD peak at 202–204 mμ in TFE and TMS. These peaks and troughs may be assigned to splitting of the π–π* transition. The CD spectra of poly(+)C3A(+)C3MB in nonacidic media are quite different from those in acidic media: they are almost mirror images. The CD spectra in this transition induced by MSA suggests that a transition from a compact helix to another more extended helix with opposite handedness occurs similar to poly-L-proline I ? II. This transition may be explained by electrostatic repulsion between protonated amide groups. Viscosity data have shown that the conformation is changed to a highly extended from in acidic media. The polyamides and diamides derived from enantiomers exhibit mirror image spectra. Poly(+)C3A(+)C3B and poly(+)C3A(+)C3MB in every solvent studied exhibit a marked enhancement of the rotatory strength of ORD and CD with respect to the corresponding diamide models. 相似文献
18.
19.
Minoru Nagata 《Macromolecular rapid communications》1996,17(8):583-587
Poly(hexamethylene adipate) copolymers with 10–40 mol-% (in feed) of aliphatic diamines of various methylene chain lengths were prepared by melt polycondensation. In vitro degradation was performed in buffer solution at 37°C with a lipase and was evaluated by weight loss of the films. The weight loss increased greatly by the copolymerization and showed a maximum at 10 mol-% of comonomer content. Degradation also increased in a zig-zag fashion with decreasing number of methylene chains in the diamine comonomers. Both effects on the enzymatic degradation are discussed. 相似文献
20.
Masaru Yoneyama K. D. Athula Kuruppu Masa-Aki Kakimoto Yoshio Imai 《Journal of polymer science. Part A, Polymer chemistry》1988,26(11):2917-2922
Aromatic polyamides (aramids) having inherent viscosities of 0.5–1.10 dL/g were prepared by the direct polycondensation of 1,1,3-trimethyl-3-(4-carboxyphenyl)indane-5-carboxylic acid with various aromatic diamines using triphenyl phosphite and pyridine as the condensing agents. Copolyamides were also prepared by a similar procedure from a mixture of the phenylindane diacid, terephthalic acid, and p-phenylenediamine. Almost all of the aramids were soluble in a variety of solvents such as N-methyl-2-pyrrolidone, pyridine, and m-cresol, and afforded transparent and tough films by the solution casting. These aramids and copolyamides had glass transition temperatures in the range of 290–355°C, and started to lose weight at 340°C in air. 相似文献