Russian Journal of Applied Chemistry, 2010, Vol. 83, No. 11, pp. 2011−2015.
Pleiades Publishing, Ltd., 2010.
Original Russian Text © A.A. Molodova, N.V. Volkova, D.N. Emel’yanov, V.I. Faerman, and T.A. Doronina, 2010, published in Zhurnal Prikladnoi Khimii,
2010, Vol. 83, No. 11, pp. 1879−1884.
AND POLYMERIC MATERIALS
Thermal Oxidative Degradation of Composites
of Cellulose Fabric with Acrylic Copolymers
A. A. Molodova, N. V. Volkova, D. N. Emel’yanov, V. I. Faerman, and T. A. Doronina
Lobachevsky Nizhni Novgorod State University, Nizhni Novgorod, Russia
Received February 17, 2010
Thermal oxidative degradation of composites consisting of two incompatible polymers was studied
by gravimetry and gas chromatography–mass spectrometry.
Polymeric materials are very sensitive to heat.
Therefore, problems of their heat resistance and its
enhancement remain topical. Today the overwhelming
majority of polymers are used as composite materials.
Composites based on acrylic polymers reinforced with
cellulose fabric are blends of two interpenetrating
colloidal networks. Thermal behavior of such complex
incompatible polymers is still insufﬁ ciently studied and
is of much scientiﬁ c interest. In particular, such systems
arise when works of art made of fabric are restored and
conserved by impregnation with polymers. Synthetic
polymers acquire today the leading role as conservers
for works of arts of various woven materials .
Polyacrylates and, in particular, poly(butyl methacrylate)
(PBMA) are widely used for this purpose. However,
PBMA is rarely used for fabric conservation because
it makes the fabric rigid. It is natural to expect that it
will be possible to develop poly(butyl methacrylate)-
based polymeric compounds that will be better suited
for restoration works.
As compared to other substances (metals, minerals),
polymeric materials without stabilizers are considerably
less resistant to aging. They change their properties and
lose strength and elasticity, up to spontaneous destruction
of an article even without external forces. This behavior
is caused by degradation of the constituent polymers .
In this study we examined the thermal oxidative
degradation of acrylic (co)polymers, cellulose fabric,
and composites of the fabric with the copolymer applied
onto it. One of the causes of the destruction of articles is
thermal oxidative degradation occurring when a fabric
work of art is exposed to extreme conditions . In
this connection, it was interesting to determine whether
a polymeric conserver can protect fabric items from
destruction at high temperatures.
Experiments were performed with poly(butyl
methacrylate) (PBMA), binary copolymers of butyl
methacrylate (BMA) with butyl acrylate (BA) or vinyl
acetate (VA), and ternary copolymers of BMA with
BA and VA. The composition and some properties of
the (co)polymers are given in Table 1. The homo- and
copolymers were prepared by radical polymerization
of the monomers in isopropyl alcohol at 80°С. The
content of the (co)monomers in the reaction mixture
with BMA was 5 and 10 mol %. As initiator we used
azobis(isobutyronitrile) (AIBN). The initiator amount in
the synthesis was varied from 0.05 to 2 wt % relative to
the sum of the comonomers.
It follows from Table 1 that the polymerization of the
(co)monomers goes to high conversions (Р). Therefore,
it can be considered that the overall composition of the
copolymers formed is close to the composition of the
initial monomer mixtures.
The molecular weights (MW) of the copolymers
were determined by gel permeation chromatography
in tetrahydrofuran at 40°С with a Shimadzu liquid
chromatograph. The columns were packed with