ISSN 1070-4272, Russian Journal of Applied Chemistry, 2014, Vol. 87, No. 9, pp. 1344−1349. © Pleiades Publishing, Ltd., 2014.
Original Russian Text © N.S. Kitaeva, Yu.M. Shiryakina, A.A. Novikova, A.A. Shimkin, 2014, published in Zhurnal Prikladnoi Khimii, 2014, Vol. 87, No. 9,
AND POLYMERIC MATERIALS
Inﬂ uence of Phosphazenes of Various Structures
on the Curing Parameters and Thermal Oxidative
Degradation of Oligomethylphenylsiloxane
N. S. Kitaeva, Yu. M. Shiryakina, A. A. Novikova, and A. A. Shimkin
All-Russian Scientiﬁ c Research Institute of Aviation Materials, ul. Radio 7, Moscow, 105005 Russia
Received August 20, 2014
Abstract—Scientific and applied aspects of possible use of cyclic phosphazenes, by-products from
phosphonitrilic anilide synthesis, as thermal stabilizers were considered. The solubility and thermal oxidative
stability of phosphonitrile anilide trimer and tetramer were studied, the dependence of the curing parameters
of oligomethylphenylsiloxane compositions (gel time, temperature intervals of curing) from the structure of
the modifying additive was examined, and the resistance of compositions based on oligomethylphenylsiloxane
modiﬁ ed with linear and cyclic oligophosphazenes to thermal oxidation at 350°C was evaluated.
Analysis of the world’s literature and of general trends
in the progress of materials science shows that much
attention is given today to research and development
in the ﬁ eld of composite materials (CMs), reinforcing
components, binders for them, and technologies of their
processing to obtain high-tech innovation products .
The most widely used binders in the production of
glass-reinforced plastics are unsaturated polyester, phe-
nol–formaldehyde, epoxy, and organosilicon resins [2–4].
The base materials for heat-resistant matrices of glass-
reinforced plastics are organosilicon and polyimide poly-
mers containing organoelement fragments and linear or
crosslinked carbo- and heterocyclic aromatic systems .
Interest in organosilicon binders is due to their high
resistance to thermal oxidation and good dielectric
A number of heat-resistant glass-reinforced plastics
with organosilicon binders have been developed in the
All-Russian Scientiﬁ c Research Institute of Aviation
Materials. These materials, capable of long operation
at 300–350°C and short operation at 800°C, have found
wide use in aviation, spaceship, and other fields of
engineering [7, 8]. Among other materials, SK-9FA glass-
reinforced plastic with organosilicon binder containing
phosphonitrile anilide (PNA) as one of the components
has been developed. Items of this glass-reinforced plastic
are still produced on commercial scale.
The modern approach to enhancing the thermal
oxidation resistance of organosilicon binders for poly-
mer composite materials (PCMs) operating for a long
time at temperatures higher than 300°C consists in
searching for effective thermostabilizing additives .
Aminophosphazenes commonly prepared by nucleophilic
substitution of chlorine atoms in chlorocyclophosphazene
with amines were traditionally used as such additives .
The reaction products are mixtures of linear and cyclic
Recently an improved procedure for the synthesis of
phosphonitrile anilide has been developed at the State
Research Institute of Chemistry and Technology of
Organoelement Compounds, allowing preparation of
mainly linear polymer oligophosphazenes. To ensure
complete solubility of phosphonitrilic anilide with the
aim of its uniform introduction into the composition,
it is necessary to remove from the target product large
amounts (up to 25%) of cyclic oligomers, which makes
the process more expensive.