2014 (4) 9

Thermal kinetic parameters of the pyrolisys of diisocyanates blocked with dimethylglioxime

A.V. Hubina, T.V. Dmуtrieva, V.I. Bortnitsky, O.V. Komlyakova

Institute of Macromolecular Chemistry NAS of Ukraine

48, Kharkivske shose, Kyiv,02160, Ukraine

Polym. J., 2014, 36, no. 4: 401-405.

Section: Structure and properties.

Language: Russian.

Abstract:

Via the method of pyrolitic mass-spectrometry the thermal properties of dimethylglioxime blocked diisocyanates were investigated and thermal kinetic parameters of their thermal destruction were calculated. Pyrolysis of HMDIb and TDIb is a one-stage process of urethane group thermal decomposition, which results in formation of both the diisocyanate and the blocking agent. The last is confirmed by the mass-spectra of the pyrolysis products. These TDIb and HMDIb are charachterized with deblocking temperature of 125 и 145 °С, respectively. The thermal deblocking process is the first order reaction both for TDIb and HMDIb, which is charachtarized (calculated via Coats-Redfern method) with activation energy » 250 кДж/моль and preexponential factor 8,5 с-1. Thermal kinetic data calculated according to Coats-Redfern are confirmed by oned obtained by Broido method.

Keywords: blocked isocyanates, dimethylglyoxime, thermal kinetics, pyrolitic mass-spectrometry.

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