Russian Journal of Applied Chemistry, 2012, Vol. 85, No. 11, pp. 1748−1752.
Pleiades Publishing, Ltd., 2012.
Original Russian Text © P.V. Kornienko, K.V. Shirshin, Yu.P. Gorelov, 2012, published in Zhurnal Prikladnoi Khimii, 2012, Vol. 85, No. 11, pp. 1842−1846.
AND POLYMERIC MATERIALS
Preparation of Foamed Polymethacrylimide Structural Materials
from Cross-Linked Copolymers of Acrylonitrile
and Methacyrlic Acid
P. V. Kornienko, K. V. Shirshin, and Yu. P. Gorelov
Kargin Research Institute of Polymer Chemistry and Technology with Pilot Plant,
Dzerzhinsk, Nizhni Novgorod oblast, Russia
Received July 26, 2012
Abstract—A study of the inﬂ uence exerted by the structure and concentration of cross-linking monomers on the
structure and physicomechanical properties of polymethacrylimide foamed plastics formed by heat treatment of
acrylonitrile–methacrylic acid copolymers showed that the use of allyl methacrylate, ethylene glycol dimethacry-
late, or triallyl isocyanurate as cross-linking monomers allows preparation of foamed materials with the density
in the range 90–180 kg m
and with enhanced strength. A study by differential scanning calorimetry showed that
the foamed plastics based on the cross-linked copolymers remain stable on heating to 200–210°С. This fact allows
these materials to be used as thermal adhesives in multilayered items.
Multilayered structures combining useful properties
of different polymer layers are widely used in modern
structural materials. For example, processes involving
gluing and forming of sandwich panels consisting of
thin external layers of carbon- or glass-reinforced plastic
and a thick internal layer of light ﬁ ller are widely used
in fabrication of parts for plane fuselages, for bodies of
railway coaches, cars, and boats, and for engine cowls
. Owing to such design, a multilayer part acquires high
strength in combination with low weight. Fabrication of
sandwich panels usually involves gluing and pressure
molding at high temperatures (130–190°С) . Therefore,
increased requirements are imposed on the heat resistance
and strength of the ﬁ ller material, and also on the sorption
of the adhesive layer and on the moisture absorption.
Recently foamed polymethacrylimides (PMIs) came
into use beyond Russia as internal ﬁ ller for multilayered
structures [3, 4]. These materials are prepared by heat
treatment of block copolymers of methacrylonitrile
(MAN) and methacrylic acid (MAA) in the presence of
various foaming agents . The heat treatment of the
copolymers leads to foaming accompanied by imidiza-
tion involving acid and nitrile units of the copolymers,
with the formation of glutarimide rings (see scheme).
As a result, a foamed plastic with a rigid closed cellular
structure is formed. As compared to polyurethane and
polyvinyl chloride foams, it exhibits higher levels of heat
resistance and strength .