Polymers thermoresistance

Thermal Stability of Engineering Heterochain Thermoresistant Polymers E. VKalugina, K.Z. Gumargalieva and G.E. Zaikov... 

Most of the imide type polymers have rather good thermoresistance. For example LaRC-l-TPI starts decomposing at about 510 C. Pyrolysis products of these polymers generate various fragment molecules related to the polymer structure. Several results reported in literature regarding thermal decomposition of some polymers from this class are indicated in Table 13.4.2. 

Tert-butylation is an important reaction as the products of this reaction, tert-butyl phenols are used as antioxidants, in the synthesis of various agrochemicals, fragrance compounds, thermoresistant polymers and protecting agents for plastics. The other products namely 0-butyl and butenyl phenols are used in the synthesis of flavouring, fragrance compounds and pharmaceutical intermediates, chromans[l]. 

Specific Features of the Thermo-oxidation of Thermoresistant Heterochain Polymers... 

Special interest in these polymers is stipulated by intensive progress in computer technology. In the last 5-10 years, a great list of publications concerning structure and properties of LCP was presented. However, there is little information on thermoresistance and specific features of ECP degradative behaviour. Authors have studied degradative transformations... 

It is common knowledge [7, 21, 39] that thermoresistance of polymers depends npon several factors structure, molecular weight characteristics, content of macrochain defects, labile end groups (hydroxyl one, in the present case), low molecular organic admixtures (unreacted monomers residues) or inorganic ones (admixtures of metal ions appearing in a polymer from the raw material and equipment) in macromolecules. 

Composition and concentration of organic admixtures in LCP were studied by mass spectroscopy. In admixtures of phenol and dioxydiphenyl (m/e 94 and 186) - the hydrolysis product of the initial monomer (dioxydiphenyl diacetate), p-oxybenzoatedioxydiphenyl and oxydiphenyl acetate were identified. Total amount of organic admixtures in different samples did not exceed (1.0-2.0) x 10 wt.% - this had no effect on thermoresistance of polymers. 

E.V. Kalugina, Thermal Transformations and Stabilisation of Some Thermoresistant Heterochain Polymers, 1992, GS Petrov RIPM, Moscow, Russia. [Thesis on Chemical Sciences] (In Russian)... 

Makromolekulare Chemie 194, No.6, June 1993, p.1545-59 LEVEAR-TEMPERATURE PROGRAMMED PYROLYSIS OF THERMORESISTANT POLYMERS - MASS AND FTIR SPECTROMETRIES. II. AROMATIC POLYESTERS AND COPOLYESTERS Hummel D 0 Neuhoff U Bretz A Duessel H J Koln,Universitat Angewandte Spektrometrie Koeln eV... 

D. O. Hummel, U. Neuhoff, A. Bretz, and H.-J. Dussel, Linear-temperature programmed pyrolysis of thermoresistant polymers—mass and FTIR spectrometries, 2, Aromatic polyesters and copolyesters, MakromoZ. Chem., 194, 1545 (1993). 

No further light was eventually throvm on the kinetics and mechanism of diacetone acrylamide electropolymerization by a report by Oliver a technological interest was however claimed for the polymer films prepared this way, whidi when cured at 180-200 °C would become thermoresistant and completely insoluble in any solvent. 

Kalugina, E. V., Gumaragalieva, K. Z., and Zaikov, G. E. 2005. Thermal Stability of Engineering Heterochain Thermoresistant Polymers, VNU Science Publishers, Leiden, The Netherlands. 

In the first stage, up to 10% of carbon is removed with carbon oxides. Relation of this percent to the content of anomalous structures in the polymer indicates that different structure degree is too high, much higher than the sensitivity of spectral methods. Meanwhile, preliminary analyses of studied thermoresistant polymeric materials (TP) showed their correspondence to postulated formulae, i.e. PSF corresponds to bisphenol A-derived polysulfone structure, PAl corresponds to fatty-aromatic polyimide derived fi om PPA and dodecamethylene diamine, etc. 

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