1070-4272/03/7611-1832$25.00C2003 MAIK [Nauka/Interperiodica]
Russian Journal of Applied Chemistry, Vol. 76, No. 11, 2003, pp. 1832!1834. Translated from Zhurnal Prikladnoi Khimii, Vol. 76, No. 11,
2003, pp. 1883!1885.
Original Russian Text Copyright + 2003 by Abdrakhmanova, Fakhrutdinova, Khozin.
AND POLYMERIC MATERIALS
Diffusion Modification of Polymethyl Methacrylate
with Oligoglycol Acrylates
L. A. Abdrakhmanova, V. Kh. Fakhrutdinova, and V. G. Khozin
Kazan State Architectural and Building Academy, Kazan, Tatarstan, Russia
Received June 18, 2003
Abstract-The structural transformations of oligoglycol acrylates in the surface layers of polymethyl
methacrylate were studied.
Surface bursting resulting in development of cracks
with the depth of 132 mm and more ([silver] forma-
tion) is characteristic of polymethyl methacrylate
(PMMA) plexiglass. Under conditions of artificial and
natural aging, evaporation of low-molecular-weight
substances, and action of various factors, significant
defects are formed, altering the physicomechanical,
optical, and other characteristics of plexiglasses.
Factors deteriorating the strength of the surface layer
of glass play an extremely important part in appear-
ance of [silver.] The appearance of [silver] is es-
pecially affected by almost all organic solvents.
The real method of strengthening the surface layers
is creation of gradient interpenetrating networks
(IPNs) , blends of three-dimensional polymers in
which concentrations of components vary through the
cross section of the sample. Introduction of oligo-
glycol acrylates of various structures, polymers based
on which are characterized by increased softening
point and hardness , into the surface layers of
PMMA allows production of materials of the gradient
semi-IPN type with enhanced performance.
Diffusion swelling of PMMA in oligoglycol acry-
lates, ethylene glycol dimethacrylate (EGDMA), tri-
ethylene glycol dimethacrylate (TEGDMA), and poly-
ethylene glycol dimethacrylate (PEGDMA), was
carried out at 37, 42, and 50oC. The degree of swel-
ling of PMMA in the oligomers is presented in
Table 1. The kinetic curves of PMMA swelling in
acrylates at 50oC are shown in Fig. 1.
Table 1 shows that, with increasing molecular
weight (correspondingly, with decreasing fraction of
acrylate groups in oligomer molecules), the degree of
swelling increases. Apparently, the rate of polymeriza-
tion of oligoglycol acrylates increases with decreasing
their molecular weight, which results in an increase
in the viscosity of oligoglycol acrylates in the course
of diffusion and, correspondingly, in a decrease in
To identify the spectra of the gradient PMMA, we
recorded the IR spectra of polyglycol acrylates pre-
pared by polymerization of the corresponding oligo-
mers. The spectra of the diffusion-modified PMMA at
various depths of the samples were obtained by laser
The characteristic bands for polyglycol acrylates
based on EGDMA are 1639 and 1283 cm
1283.5 for PEGMA, and 1283.6 cm
The band at 988.2 cm
in the spectrum of PMMA
was selected as the reference for calculations.
Processing of the spectra and determination of the
intensity ratio of the characteristic bands to the refer-
ence band at 988.2 cm
at various depths from the
sample surface allowed determination of the relative
content of oligomers in the surface layers of the sam-
ples. The results are presented in Table 2.
As follows from Table 2, the dependence of the
oligomer concentration on the depth of its penetration
into the PMMA matrix has a maximum (Fig. 2). For
Table 1. Degree of swelling of PMMA a in oligomers
³ a, wt %, at indicated treatment
³³30 ³ 60 ³ 90
37 ³EGDMA ³ 0.8 ³ 2.3 ³ 4.3
³TEGDMA ³ 3 ³ 3 ³ 3
³PEGDMA ³ 7.2 ³ 11.4 ³ 16.2
50 ³EGDMA ³ 1.9 ³ 6.6 ³ 10.4
³TEGDMA ³ 7.8 ³ 11.8 ³ 13.5
³PEGDMA ³ 15.4 ³ 18.0 ³ 20.8
is the swelling temperature.