2014 (3) 8

Pyrolytic mass-spectrometry of some liquid rubbers obtained by radical polymerization

Т.V. Dmitrieva, V.I. Bortnytskiy, V.P. Boiko, V.К. Grishchenko

Institute of Macromolecular Chemistry NAS of Ukraine

48, Kharkivske shose, Kyiv, 02160, Ukraine

Polym. J., 2014, 36, no. 3: 276-281.

Section: Structure and properties.

Language: Russian.

Abstract:

By the method of pyrolytic mass spectrometry,  thermal stability of a number of liquid rubbers obtained by radical polymerization using hydrogen peroxide as an initiator ( ORD ) in isopropyl and n-butyl alcohols, and azo initiators having terminal hydroxyl or nitrile group, has been evaluated. It was found that thermal stability of oligoisoprene obtained with hydrogen peroxide, temperatures of beginning gas release and maximum, as well as the composition of volatile products correspond to parameters of that based on azo-bis-isobutyronitrile.  The volatile products, including those of oxygen-containing groups, were assigned. Despite the high oxidizing power of hydrogen peroxide and the presence of oxygen-containing groups in ORD oligomers, their thermal stability is not reduced. A low-temperature peak appears in the sample obtained in n-butyl alcohol due to the inclusion into oligomer some number of weak bonds. A sample of oligobutadiene has a higher thermal stability than oligoisoprene obviously to the  stabilization of an  isoprene radical, which forms during the pyrolysis, by methyl group.

Key words: liquid rubbers, initiators, thermostability.