Journal ArticleDOI
Thermally stable soluble polyimides
TLDR
In this paper, a new method has been developed for the synthesis of high molecular aromatic polyimides, a one-step high-temperature polycyclization in solution, which substantially simplifies the synthesis and their application.Abstract:
1.
A new method has been developed for the synthesis of high molecular aromatic polyimides — a one-step high-temperature polycyclization in solution, which substantially simplifies the synthesis of such polymers and their application.
2.
An idea of the molecular weights and coefficient of polydispersion of polyimides was obtained for the first time, with soluble polydiphenylenphthalidepyromellitimide as an example.
3.
Certain physicochemlcal properties of polyimides of anilinephthalein and anilinephthaleinimide were studied, and it was shown that these polymers possess a valuable complex of properties: high mechanical indices, excellent thermal stability, which in conjunction with the good solubility of these polyimides, makes them extremely promising for practical utilization.
4.
The question of the influence of various structural factors upon the solubility of polyimides was discussed, and it was shown that the solubility of polyimides of anilinephthalein and anilinephthaleinimide is due to the large size of the phthalide and phthalimidine side groups and to their polarity.read more
Citations
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Patent
Polymers exhibiting nonlinear optical properties
TL;DR: In this paper, the authors proposed a non-linear optical properties of polymers having nonlinear optical property, which polymers include fluorene moieties having at least one electron accepting group and at least electron donating group substituted to different phenyl rings of the fluorenes moiety (I), wherein: A is an electron withdrawing substituent; D are an electron donating substituents; R?1 and R2? are the same or different and are divalent conjugated organic or inorganic moiety.
Book ChapterDOI
Synthesis of Polyimides in the Melt of Benzoic Acid
Abstract: Review of the authors’works on the synthesis of polyimides (PIs) by the method of one-stage high-temperature polycondensation in an unusual solvent—molten benzoic acid (BA). Compared with a known synthesis in inert high-boiling solvents, synthesis in BA takes place under mild conditions (140°C, 1–2 hour) to give completely imidized PIs. The approach has a number of advantages. Due to catalysis of the first reversible stage of amiс acid (AA) formation and low equilibrium constant (K = 10–20 l/mol), the first stage disappears kinetically, and the imidization reaction becomes limiting. The process becomes less sensitive to the basicity of diamines; therefore, low reactivity diamines can be involved. Water is easily removed from the melt by evaporation, which makes the whole process irreversible. Specific features of the method are successfully used to control the microstructure of the chain copolyimides (statistical to multiblock) and to synthesize hyperbranched PIs and star-shaped PIs with narrow molecular weight distribution.
References
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Journal ArticleDOI
Thermal degradation of an aromatic polypyromellitimide in air and vacuum III—Pyrolytic conversion into a semiconductor☆
TL;DR: In this article, the pyrolytic conversion of poly[N,N′-(p,p′-oxydiphenylene) pyromellitimide] to semiconducting products is discussed as supported by data on electron paramagnetic resonance (e.p.r.) absorption, specific resistivity, weight loss, density, and composition.
Journal ArticleDOI
Thermal degradation of an aromatic polypyromellitimide in air and vacuum II—The effect of impurities and the nature of degradation products
TL;DR: In this article, the effect of impurities on the thermal degradation of poly-[ N, N n ·-( p, p ·-oxydiphenylene) pyromellitimide (du Pont's 'H'-film) is discussed.