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1.
Summary A poly(ether-imide) was prepared by thermal imidization of poly(amic-acid) intermediate resulting from the solution polycondensation
reaction of a bis(ether-anhydride), namely 2,2′-bis-[(3,4-dicarboxyphenoxy)phenyl]-1,4-phenylene-diisopropylidene dianhydride,
with an aromatic diamine containing two isopropylidene groups, namely 4,4′-(1,4-phenylenediisopropylidene)bisaniline. A poly(ether-imide)-polydimethylsiloxane
copolymer was prepared by polycondensation reaction of the same bis(ether-anhydride) with an equimolar quantity of the aromatic
diamine having isopropylidene groups and a bis(aminopropyl)polydimethylsiloxane oligomer of controlled molecular weight. A
solution imidization procedure was used to convert quantitatively the poly(amic-acid) intermediates to the corresponding polyimides.
The polymers were easily soluble in polar organic solvents and showed good thermal stability with decomposition temperature
being above 400 °C. Electrical insulating properties of poly(ether-imide)-polydimethylsiloxane copolymer film were evaluated
on the basis of dielectric constant and dielectric loss and their variation with frequency and temperature. 相似文献
2.
Chin-Ping Yang Yung-Chung Chen Sheng-Huei Hsiao Wenjeng Guo Hui-Min Wang 《Journal of Polymer Research》2010,17(6):779-788
A series of colorless and organosoluble poly(ether-imide)s (PEIs) were prepared from a phenylhydroquinone bis(ether anhydride),
i.e., 2,5-bis(3,4-dicarboxyphenoxy)biphenyl dianhydride, and seven trifluoromethyl-containing bis(ether amine)s by the conventional
two-stage process via the thermal or chemical imidization of the precursor poly(amic acid)s. The fluorinated PEIs prepared
via the chemical imidization procedure had inherent viscosities of 0.46–1.27 dL/g and weight-average molecular weights of
68,000–87,500. The PEIs exhibited good solubility in a variety of organic solvents; they were readily soluble in amide-type
polar solvents and chlorinated hydrocarbons on a concentration higher than 10%. The solution-cast films showed a high optical
transparency and low color intensity, with an ultraviolet-visible absorption edge of 368–375 nm and a yellowness index of
5.9–9.9. These films were flexible and tough with tensile strengths of 89–114 MPa. They exhibited glass-tranisition temperatures
of 198–250°C and 10% weight loss temperatures higher than 488°C in air or nitrogen. In addition, these PEI films also displayed
low dielectric constants (3.22–3.52 at 1 MHz) and low moisture absorptions (0.22–0.73 wt%). 相似文献
3.
Imide-aryl ether ether ketone block copolymers were prepared and the adhesion characteristics with poly(ether-imide) were
investigated. The copolymers were prepared via the poly(amic alkyl ester) precursor to the polyimides which is hydrolytically
stable and may be isolated and characterized prior to imidization. Solutions of the copolymers were cast and cured to effect
the imidization, producing clear tough films which showed two transitions, indicative of a multiphase morphology. Mixtures
of the copolymers with poly(ether-imide) also produced clear films, and the shift in the Tg of the aryl ether ether ketone component of the block copolymer indicated miscibility with the poly(ether-imide) within this
phase. This miscibility of the poly(ether-imide) with the aryl ether ether ketone component of the block copolymer produced
significant improvements in the adhesion of the thermoplastic poly(ether-imide) with the rigid polyimide copolymer. 相似文献
4.
Sundararaj Senthilkumar Sahadevan Rajesh Ayyavoo Jayalakshmi Gurumurthi Aishwarya Doraiswamy Raju Mohan 《Journal of Polymer Research》2012,19(6):9867
Biocompatible Polysulfone (PSf) hemodialysis membranes were prepared by phase inversion technique using poly (ether-imide)
(PEI) as the modification agent and Polyethylene glycol (PEG-200) as the pore former. The effect of PSf/PEI blend ratio on
the morphology, hydrophilicity, water content, porosity, glass transition temperature, mechanical strength, biocompatibility
and permeation rate of the prepared membranes were studied and were found to be improved significantly by the incorporation
of PEI in the dope solution. The scanning electron microscopy (SEM) studies revealed that, incorporation of PEI resulted in
the formation of spongy sub-layer and increased the connectivity of pores between sub-layer and bottom layer. The water content
and permeation rate of the membranes of PSf/PEI blend membranes were increased considerably indicating the enhancement of
hydrophilicity and it was supported by lower contact angle values of the blend membranes. The existence of single well defined
Tg over entire composition established the compatibility between the components in blend membranes. The biocompatibility of
membranes was investigated through protein adsorption, platelet adhesion and thrombus formation on the membrane surface. Anticoagulant
activity of PSf/PEI blend membranes was evaluated by measuring the activated partial thrombin time (APTT), prothrombin time
(PT), thrombin time (TT) and fibrinogen time (FT). The results revealed that antithrombogenicity of PSf/PEI blend membranes
was increased significantly. The efficiency of these membranes in removal of urea, creatinine and vitamin B12 were studied and found to be improved for blend membranes. Thus, it is worth mentioning to note that, the biocompatible PSf/PEI
blend membranes prepared in this study would offer immense potential in hemodialysis. 相似文献
5.
Stephen Edge W. James Feast Witold F. Pacynko Linda Preston Susan Walker 《Polymer Bulletin》1992,27(4):441-445
Summary The surface modification of poly(ether-imide) by the photochemical vapour phase grafting of poly(2-hydroxyethylmethacrylate) is described. After grafting for four hours the contact angle of the film surface was 62° compared to a value of 80° for an untreated sample. XPS confirmed the presence of 2-hydroxyethylmethacrylate in the polymer surface. 相似文献
6.
Four cyclolinear poly(aryloxycyclotriphosphazenes) derived from poly[4,4′‐(isopropoylidene)diphenoxytetrachlorocyclotriphosphazene] and poly[4,4′‐(hexafluoroisopropylidene)diphenoxytetrachlorocyclotriphosphazene] were synthesized from the reaction of hexachlorocyclotriphosphazene (HCP) with 4,4′‐(isopropylidene)diphenol (bisphenol A) or 4,4′‐(hexafluoroisopropylidene)diphenol (bisphenol AF) in molar ratio 1 : 1 via a one‐step condensation polymerization. Subsequent reaction of the resulted chlorine‐bound polymers with adequate amount of the sodium salts of 4‐methoxycarbonylphenoxide or 4‐propoxycarbonylphenoxide yielded the corresponding chlorine‐free polymers, [poly(tetra‐4‐methoxycarbonylphenoxy)‐4,4′‐(isopropoylidene)diphenoxy cyclotriphosphazene] (MBACP), [poly(tetra‐4‐propoxycarbonylphenoxy)‐4,4′‐(isopropoylidene)diphenoxycyclotriphosphazene] (PBACP), [poly(tetra‐4‐methoxycarbonylphenoxy)‐4,4′‐(hexafluoroisopropylidene)diphenoxycyclotriphosphazene] (MBAFCP), [poly(tetra‐4‐propoxycarbonylphenoxy)‐4,4′‐(hexafluoroisopropylidene)diphenoxycyclotriphosphazene] (PBAFCP), respectively. The chemical structures were characterized by Fourier transformer infrared, 1H, and 13C‐NMR. Thermal properties of polymers were investigated using DSC and TGA analysis. The obtained polymers were thermoplastic, having moderate Tg values in the range of 26–78°C and good thermal stability up to 350°C in N2 and O2 gases. The thermal decomposition of the isopropylidene‐containing polymers is a one‐step process, while that of hexafluoroisopropylidene‐containing polymers is a two‐step process. However, presence of the latter group in the polymers backbone showed negligible effects on the thermo‐oxidative stability. The adhesive strength was measured by lap‐shear strength test on glass–glass bonded joint and found to be in the range of 1.78–2.62 MPa, this property may be attributed to the physical interactions between glass–glass interfaces and the polar‐pendant units present at the polymers backbone. The products showed high optical transparency when they applied between two glass surfaces, the adhesive layers were colorless, with the UV cut‐off wavelength of 300–302 nm, and the maximum transparency of about 90% was observed within the wavelengths range of 400–700 nm. Because of their properties, the cyclolinear poly(aryloxycyclotriphosphazenes) synthesized in this study are recommended as potential candidates for high thermally stable, transparent adhesives required in industrial applications. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011. 相似文献
7.
Bruno Ribeiro Jefersson A. R. Corredor Laura Ardila Luis F. P. Santos Michelle L. Costa Mirabel C. Rezende Edson C. Botelho 《应用聚合物科学杂志》2020,137(5):48330
Vacuum filtration technique was employed in order to prepare multiwalled carbon nanotube buckypapers (MWCNT-BP) through a well-dispersed suspension of MWCNT/H2O with the aid of Triton X-100 surfactant. The obtained BP (buckypaper) was then infiltrated with a solution of poly (ether-imide) (PEI) under vacuum conditions. The visual inspection demonstrated the importance of the centrifugation procedure before the vacuum filtration of the suspension, revealing a smooth surface of the as-prepared buckypaper. Thermogravimetric experiments (TGA) and scanning electron microscopy analyses have demonstrated the role of isopropyl alcohol in the removal of Triton X-100 from the nanotube network. SEM observations of the cross-section view of the samples revealed a porous network of the fabricated BP, and an impregnated structure of the PEI/BP composite, suggesting a good interfacial bonding between MWCNT and PEI. Moreover, significant improvements were achieved in mechanical and thermal properties of PEI matrix by the incorporation of BP, as the increase of both the storage modulus (42%) and the T g (11 °C) for the PEI/BP composite. TGA have shown a significant increase in the onset decomposition temperature of the polymer by the incorporation of the BP. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48330. 相似文献
8.
9.
Aromatic poly(benzoxazole)s are a class of rigid‐rod conjugated polymers. However, their poor solubility in organic solvents limits potential applications. Thus, a good method that can address this dilemma is needed, given that existing methods involve models with either poor solubility but good thermal stability or good solubility but poor thermal stability. In this paper we report a novel aromatic poly(benzoxazole) with a soft linkage and a rigid pendant group. Structural characterizations of the polymers via Fourier transform infrared and proton nuclear magnetic resonance spectroscopy reveal the formation of a benzoxazole ring and an imide ring. The introduction of rigid pendant groups improved the solubility and enhanced the thermal stability of the polymer, which was impaired by the incorporation of the soft linkage. Most of these polymers are soluble at room temperature or when heated in dimethyl sulfoxide, N,N‐dimethylformamide or N,N‐dimethylacetamide. Some polymers can even be dissolved in m‐cresol and tetrahydrofuran. A 10% weight loss in these polymers was observed at temperatures over 410 °C. Moreover, the incorporation of the imide pendant group increased the conjugation length of the polymer structural unit and accelerated electron delocalization. Copyright © 2012 Society of Chemical Industry 相似文献
10.
Ju-Yeon Lee 《Polymer Bulletin》1995,35(1-2):33-40
Summary 3,5-Dimethoxy-4-(2-vinyloxyethoxy)-4-nitrostilbene 2 and 3,5-dimethoxy-4-(2-vinyloxyethoxy)-2,4-dinitrostilbene 5 were prepared by the reactions of 2-iodoethyl vinyl ether with 3,5-dimethoxy-4-hydroxy-4-dinitrostilbene 1 and 3,5-dimethoxy-4-hydroxy-2,4-dinitrostilbene 4, respectively. Monomers 2 and 5 were polymerized with cationic initiators to obtain polymers with the NLO-phores 3,5-dimethoxy-4-oxy-4-nitrostilbene and 3,5-dimethoxy-4-oxy-2,4-nitrostilbene in the side chain. The resulting polymer 3 and 6 were soluble in DMSO and DMF. The inherent viscosities of polymers were in the range of 0.28–0.33 dL/g in DMSO. Polymers 3 and 6 showed good thermal stabilities in their TGA thermograms, and the Tg values from DSC thermograms were in the range of 81–87°C. 相似文献
11.
Two series of new photosensitive poly(amide imide)s (PAIs) containing photochromic azobenzene moieties as side groups have been synthesized. For this purpose the following diamines with azobenzene groups have been prepared: 2,4-diamino-4′-fluoroazobenzene, 2,4-diamino-4′-methylazobenzene, 2,4-diamino-4′-trifluoromethoxy-azobenzene and 2,4-diamino-4′-nitroazobenzene. The poly(amide imide)s have been obtained from diamidedianhydrides and diamino-chromophores using high-temperature polycondensation. The resulting polyimides are characterized by good solubility in some solvents, high glass transition temperatures (257-280 °C), high thermal decomposition temperatures and good film forming properties. The irradiation with linearly polarized light (488 nm, 100 mW/cm2), causes a reorientation of the azobenzene groups by angular-selective EZ photoisomerization. In this way optical anisotropy is induced in the initially isotropic films casting from the amorphous polymers. The photoinduced dichroism in the films has been measured, and the results are discussed in relation to the structure of these polymers, whereas the substitution of the azobenzene moiety and the structure of the backbone are varied. 相似文献
12.
In this work, we present a simple method for preparation of an inexpensive CO2-philic amphiphiles for solubilization and related applications. The poly(ether-siloxane)s we have synthesized showed very good solubility in supercritical carbon dioxide, despite the fact they contained hydrophilic polyether structures. So far, incorporation of any type of substituents to the poly(dimethylsiloxane) (PDMS) chains resulted in decrease of the solubility in scCO2. We showed that, it is possible to obtain copolymers containing both hydrophilic (polyether) and hydrophobic (polysiloxane) parts which have better solubility in scCO2 than respective homopolymers. The proposed synthetic route should allow the design of a wide range of related CO2-philic hyperbranched materials. 相似文献
13.
Ritchie A. Wessling 《应用聚合物科学杂志》1970,14(6):1531-1545
The relative abilities of various solvents to dissolve crystalline polyvinylidene chloride were judged by comparing temperatures at which dilute suspensions became homogeneous. PVDC is not soluble in common solvents at ambient temperatures. It dissolves in solvents of matching solubility parameter only above ~130°C. An analysis of the data suggests that δ = 10.1 for PVDC. Five classes of specific solvents were observed that could dissolve PVDC at much lower temperatures. These include sulfoxides, dialkyl amides, alkyl lactams, cyclic sulfides, and cyclic ketones. PVDC acts as a weak Lewis acid in these solutions. The best solvents found, in order of decreasing activity, are: hexamethylphosphoramide, tetramethylene sulfoxide, N-acetylpiperidine, N-methylpyrrolidone, N-formylhexamethyleneimine, and trimethylene sulfide. 相似文献
14.
Nonlinear optical (NLO) poly(adamantyl methacrylate-methylvinylurethane)s were prepared by functionalisation of adamantyl methacrylate vinyl isocyanate precursor polymers. A modified pathway to obtain phenyltetraene-bridged chromophore was worked out. Poled films of the polymers show high and very stable NLO response even at elevated temperatures. 相似文献
15.
Nawadon Petchwattana Phisut Naknaen Jakkid Sanetuntikul Borwon Narupai 《塑料、橡胶和复合材料》2018,47(4):147-155
In this paper, dimethylbenzylidene sorbitol (DMBS) was applied to poly(lactic acid) (PLA) as a nucleating and clarifying agents. Eight level concentrations, from 0.25 to 10?wt-%, were added and measured some changes in the thermal, mechanical, physical and morphological properties. Experimental results revealed that the nucleated PLA crystallised earlier together with the reductions of the crystallisation temperature (Tc) at all DMBS concentrations, while the glass transition temperature (Tg) reduced by around 10°C. The degree of crystallinity (Xc) increased from 1.48 to 16.6% corresponding to the decreased crystallisation time (tc) from more than 40 to less than 5?min at 100°C. The nucleated PLA maintained its clarity at all DMBS concentrations, with reductions of the haze value from around 36–29%. The tensile modulus and tensile strength increased slightly with the content of DMBS up to 1.5?wt-%. Beyond this content, they dropped slightly. 相似文献
16.
Minoru Nagata Tsuyoshi Kiyotsukuri Susumu Minami Naoto Tsutsumi Wataru Sakai 《Polymer International》1996,39(2):83-89
Poly(ethylene terephthalate) copolymers were prepared by melt polycondensation of dimethyl terephthalate and excess ethylene glycol with 10–40mol% (in feed) of poly(ethylene glycol) (E) and poly(tetramethylene glycol) (B), with molecular weight (MW) of E and B 200–7500 and 1000, respectively. The reduced specific viscosity of copolymers increased with increasing MW and content of polyglycol comonomer. The temperature of melting (Tm), cold crystallization and glass transition (Tg) decreased with the copolymerization. Tm depression of copolymers suggested that the E series copolymers are the block type at higher content of the comonomer. Tg was decreased below room temperature by the copolymerization, which affected the crystallinity and the density of copolymer films. Water absorption increased with increasing content of comonomer, and the increase was much higher for E1000 series films than B1000 series films. The biodegradability was estimated by weight loss of copolymer films in buffer solution with and without a lipase at 37°C. The weight loss was enhanced a little by the presence of a lipase, and increased abruptly at higher comonomer content, which was correlated to the water absorption and the concentration of ester linkages between PET and PEG segments. The weight loss of B series films was much lower than that of E series films. The abrupt increase of the weight loss by alkaline hydrolysis is almost consistent with that by biodegradation. 相似文献
17.
18.
Yongshun Wang Yuxi Dou Zhengzhe Wu Yingxin Tian Yiming Xiong Juan Zhao De Fang Fuzhi Huang Yi-Bing Cheng Jie Zhong 《Frontiers of Chemical Science and Engineering》2023,17(2):206
Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is an important organic electrode for solution-processed low-cost electronic devices. However, it requires doping and post-solvent treatment to improve its conductivity, and the chemicals used for such treatments may affect the device fabrication process. In this study, we developed a novel route for exploiting ultrafast lasers (femtosecond and picosecond laser) to simultaneously enhance the conductivity and transparency of PEDOT:PSS films and fabricate patterned solution-processed electrodes for electronic devices. The conductivity of the PEDOT:PSS film was improved by three orders of magnitude (from 3.1 to 1024 S·cm–1), and high transparency of up to 88.5% (average visible transmittance, AVT) was achieved. Raman and depth-profiling X-ray photoelectron spectroscopy revealed that the oxidation level of PEDOT was enhanced, thereby increasing the carrier concentration. The surface PSS content also decreased, which is beneficial to the carrier mobility, resulting in significantly enhanced electrical conductivity. Further, we fabricated semitransparent perovskite solar cells using the as-made PEDOT:PSS as the transparent top electrodes, and a power conversion efficiency of 7.39% was achieved with 22.63% AVT. Thus, the proposed route for synthesizing conductive and transparent electrodes is promising for vacuum and doping-free electronics. 相似文献
19.
Pentafluorophenyl sulfone was prepared by oxidation of pentafluorophenyl sulfide. Ethynyl terminated fluorinated poly(arylene ether sulfone) (EFPAESO) was synthesized via nucleophilic aromatic substitution from 4,4′-(hexafluoroisopropylidene) diphenol or 4,4′-(trifluoromethylphenylisopropylidene) diphenol with an excess of pentafluorophenyl sulfone, followed by reaction with 3-ethylnylphenol. The molecular weights (Mns) of the polymers determined by GPC with polystyrene standard were in the range of 6,400-17,200 and polydispersities (Mw/Mns) were in the range of 2.25-3.19. This EFPAESO showed very high thermal stability up to 479 °C for 5% weight loss in TGA in air. Tg of the polymer was changed from 148 to 196 °C after curing. The cured films showed good chemical resistance and high thermal-stability. At 1550 nm wavelength, the refractive indices of the copolymer films were in the range of 1.5037-1.5504 and birefringences were in the range of 0.0021-0.0025. The optical loss for EFPAESO was less than 0.37 dB/cm at 1550 nm wavelength. 相似文献
20.
Summary Optical polymers which exhibit good thermal stability, controllable refractive index, and low optical loss in the optical communication wavelengths of 1.3 and 1.55 μm were synthesized from 4,4'-(hexafluoroisopropylidene)diphenol (bisphenol AF) and decafluorobiphenyl. The copolymers were prepared by the appropriate molar ratio of 4,6-dichlororesorcinol and bisphenol AF with decafluorobiphenyl. Optical properties such as refractive index and absorption behavior in the near IR region of the resulting polymers were characterized. As the content of chlorine was increased, the refractive indices of polymer were increased without causing further optical loss. Embedded optical waveguides were fabricated by using fluorinated and chloro-fluorinated poly(arylene ether)s. Received: 2 June 1998/Revised version: 27 July 1998/Accepted: 4 August 1998 相似文献