Processing of acetophenon bottoms from distillation of styrene with maleic acid

Article abstract of DOI:10.1023/A:1020913011612

The kinetic features of dehydration of maleic acid during preparation of a copolymer based on the styrene distillation bottoms from joint production of styrene and propylene oxide were studied. The potential application fields for the copolymer synthesized were analyzed.

Full text of DOI:10.1023/A:1020913011612

Russian Journal of Applied Chemistry, Vol. 75, No. 8, 2002, pp. 1290 1295. Translated from Zhurnal Prikladnoi Khimii, Vol. 75, No. 8, 2002,
pp. 1315 1319.
Original Russian Text Copyright
2002 by Filimonova, Nikulin.
ORGANIC SYNTHESIS
AND INDUSTRIAL ORGANIC CHEMISTRY
Processing of Acetophenon Bottoms from Distillation
of Styrene with Maleic Acid
O. N. Filimonova and S. S. Nikulin
Voronezh State Technological Academy, Voronezh, Russia
Voronezh State Forestry Engineering Academy, Voronezh, Russia
Received December 26, 2001; in final form, March 2002
Abstract The kinetic features of dehydration of maleic acid during preparation of a copolymer based on
the styrene distillation bottoms from joint production of styrene and propylene oxide were studied. The po-
tential application fields for the copolymer synthesized were analyzed.
Processing and utilization of waste and by-products
from chemical, petrochemical, and other industries
receive now much attention both in Russia and abroad.
These allow both mitigation of the environmental pol-
lution and preparation of new materials with a set of
valuable properties. Of the greatest importance among
the wide variety of waste products are those from
styrene production, namely, styrene distillation bot-
toms (SDB). One of the best ways of SDB utilization
is processing into polymeric products by copolymer-
ization with other monomers, most often, maleic
anhydride (MA).
The kinetics of the maleic acid dehydration by
the reaction
k1
MAc
MA + H O
2
k 1
can be described by the following mathematical
model:
dcMAc/dt = k1 cMAc + k 1 cMA cW .
(1)
Here, cMAc, cMA, and cW are the concentrations
of maleic acid, maleic anhydride, and water at instant
Reactions of styrene and its oligomers with maleic
anhydride and widely covered in literature [1 5]. It
has been shown that this copolymer can yield good
paint and varnish materials. Application of maleic
anhydride is, however, not always advisable because
of its short supply and high price. At the same time,
it should be noted that maleic anhydride production
yields large amounts of maleic acid (MAc) as by-
product, which is suitable for copolymerization with
styrene instead of maleic anhydride. This, undoubted-
ly good alternative allows integrated processing of
the waste. However, the behavior of maleic acid in
copolymerization still remains to be understood. The
use of this waste requires extensive studies of both
the copolymerization process and its mechanism and
the quality of the resulting polymeric product and its
behavior in various composite materials.
of time t, respectively, and k and k 1 are the rate
constants of the forward and back reactions, respec-
tively.
1
In our experiments, dehydration of maleic acid
involved permanent removal of water from the reac-
tion mixture. Thus, cW can be regarded as a function
slowly varying with time. For theoretical analysis,
cW = const and, hence, k 1W = k 1 cW = const was
taken.
According to the stoichiometry of the reaction,
cMA = cMAc0
cMAc, where cMAc0 is the maleic acid
concentration at the initial moment, and cMAc0 = cMAc
at t = 0.
With the new parameters substituted, Eq. (1) takes
the form
Therefore, elucidation of the kinetic features of de-
hydration of maleic acid in the course of copolymer
preparation is of both theoretical and applied im-
portance.
dcMAc/dt + (k1 + k 1W)cMAc = k 1W cMAc0 . (2)
Differential equation (2) can be solved analytically
1
070-4272/02/7508-1290 $27.00 2002 MAIK Nauka/Interperiodica

PROCESSING OF ACETOPHENON BOTTOMS FROM DISTILLATION OF STYRENE
1291
T
Y = [0.442 0.396 0.336 0.318 0.314 0.248 0.239 0.195] ,
k 1W cMAc0
k 1W cMAc0
(k + k 1W)t
1
cMAc = cMAc0
e
+
.
T
k 1 + k 1W
k 1 + k 1W
Y = [0.442 0.305 0.280 0.195 0.158 0.127 0.097] ,
(3)
T
Y = [0.442 0.388 0.330 0.296 0.277 0.268 0.264] .
Equation (3) represents the mathematical model
of the maleic acid dehydration kinetics. To check
the suitability of the model for both theoretical and
practical applications, it is necessary to solve the in-
verse kinetic problem on determining k and k .
T
The vector A = [A A A ] , whose elements are co-
0
1
2
efficients including the kinetic constants, is to be de-
termined. Using formulas (5), we calculated k 1W
A and k = (A + A ). The results are presented in
Table 2. It is seen that the experimental and calculated
kinetic data are in good agreement. Thus, the model
proposed is adequate to the real system.
=
2
1
1
2
1
1
We studied dehydration of maleic acid at 110, 130,
and 150 C in acetophenone at initial maleic acid
concentration of 0.442 M by monitoring the variation
of the maleic anhydride content in the process by IR
spectroscopy.
The equilibrium pseudoconstant for maleic acid
dehydration was calculated by the formula
To determine the kinetic constants k and k , we
used Eq. (2) in the integral form
1
1
Table 1. Experimental data on maleic acid dehydration
t
T,
C
t, min
cMAc, M
X = c
dt
MAc
Y = A0 + A X + A X ,
(4)
1
1
2
2
0
where Y = cMAc, A = c
, A = (k + k 1W),
0
MAc0
1
1
110
0
0.442
0.396
0.336
0.318
0.314
0.248
0.239
0.195
0.442
0.305
0.280
0.195
0.158
0.127
0.097
0.442
0.338
0.330
0.296
0.277
0.268
0.264
0.000
1
5
6.289
11.782
16.691
21.434
25.647
29.294
32.546
0.000
3.735
6.661
9.032
10.792
12.212
13.331
0.000
0.831
1.549
A2 = k c
cW = k
c
,
(5)
(6)
1 MAc0
1W MAc0
30
5
60
75
0
4
t
X1
=
cMAc dt, X2 = t.
0
9
The X parameter was calculated by a numerical
1
1
05
0
procedure from the experimental data. The results are
presented in Table 1, along with the maleic acid con-
centrations (designated as Y ).
1
30
1
2
3
4
5
6
0
0
0
0
0
0
0
2
4
6
8
0
2
The coefficients A , A , and A were determined
0
1
2
by solving the problem by the least-squares method
for the equation in the matrix form
1
50
XA = Y,
(7)
where X is a matrix, and A and Y are vectors.
2.174
2.747
3.292
3.827
1
The matrix X is constructed using the X and X2
parameters for different instants of time. Using the
experimental data from Table 1 for 110, 130, and
1
1
1
50 C, we obtained
1
1
1
0
0
1
1
1
0
0
1 0
1 0.83
1 1.55
0
2
4
6
8
Table 2. Kinetic constants k and k
constants Keq
and equilibrium
1W
1
6.29 15
11.8 30
3.74 10
6.66 20
X = 1 16.7 45 , X = 1 9.03 30 , X = 1 2.17
k 1W,
T,
C
k , min 1
Keq, M
1
1
1
1
1
21.4 60
25.6 75
29.3 90
32.55 105
1 10.8 40
1 12.2 10
1 13.3 60
1 2.75
1 3.29 10
1 3.83 12
3
dm mol 1 min 1
110
130
50
5.57 10 3
2.75 10 2
1.54 10 1
0
7.54 10 4
4.90 10 2
36.5
3.14
1
For the same temperatures,
RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol. 75 No. 8 2002

1292
FILIMONOVA, NIKULIN
Keq = k /k 1W.
(8)
acid can directly participate in the chemical pro-
cess).
1
The results are presented in Table 2 as well.
The pseudoconstant tends to decrease with rising tem-
perature, which suggests heat evolution in the reaction
At the same time, the most promising line of ap-
plication of polymeric materials prepared from petro-
chemical waste and by-products still remains to be
chosen. This is due, above all, to essential drawbacks
of these polymeric materials, such as low stability of
the polymer composition governing the structure and
properties of macromolecules, high chromaticity,
opalescence, etc., which significantly limits their ap-
plication field.
[
6, 7]. In view of the shift to maleic anhydride forma-
tion with lowering temperature, k >> k 1W holds at
1
a certain temperature. Equation (3) suggests that, in
a certain time period,
k t
1
cMAc = cMAc0
e
or, in the differential form,
The aforesaid suggests that the most promising
application line is that posing not very strict require-
ments on the properties of the resulting polymeric
materials and allowing their use despite the above-
listed drawbacks. One line can be protection of wood
and wood articles against unfavorable factors. Mod-
ifying compositions intended for wood protection
should satisfy a number of requirements, namely, be
available and nontoxic, not deteriorate the principal
properties of the material, and easily penetrate into it.
Expensive protective agents significantly increase
the cost of wood articles, which makes reasonable
the use of readily available cheap petrochemical waste
and by-products and materials thereof. Also, the SDB-
based copolymer contains a large amount of carboxy
and anhydride groups which can react with wood
components to form chemical bonds.
dcMAc/dt = k c
.
1 MAc
This means that maleic acid dehydration can be re-
garded as an irreversible first-order reaction.
Our data suggest that maleic acid is 90% converted
to maleic anhydride within 5.5 and 2 h at 110 and
1
30 C, respectively. At 150 C, equilibrium is attained
within 0.3 h at 50% conversion.
The content of maleic anhydride in the reqaction
mixture was determined with an IKS-22 spectropho-
tometer. To this end, we developed a procedure for
quantitative determination of maleic anhydride from
the IR absorption spectra. Maleic anhydride is charac-
1
terized by an intense absorption band near 1840 cm ,
due to stretching vibration of anhydride groups
(
CO O CO). This band does not overlap with those
The available gel-chromatographic data show that
the SDB copolymer has a relatively low molecular
weight (M = 1900, M = 17000, M = 26500, M =
of other components and, hence, was chosen for de-
termining the content of maleic anhydride [8].
n
v
w
z
Thus, we studied the kinetics of maleic acid dehy-
dration into maleic anhydride and showed that, in
the initial stage of the combined processing of aceto-
phenone SDB and maleic acid, the temperature should
not exceed 130 C, as under these conditions the whole
of maleic acid is converted to maleic anhydride, and
formation of the product (styrene copolymer with
maleic anhydride) is highly probable. Since prepara-
tion of a film-forming copolymer at 120 170 C takes
no less than 10 h, chemical conversion of aceto-
phenone SDB below 150 C predominantly involves
the reaction with maleic anhydride. With tempera-
ture increasing at the beginning of the reaction to
above 150 C, the equilibrium of maleic acid dehy-
dration shifts to the left, and the content of maleic
anhydride participating in the copolymerization tends
to decrease. These results are important both from
the technological standpoint and for assessing the
end product quality (at elevated temperatures maleic
2
52000, M /M = 13.8, M /M = 9.5). Evidently,
w n z w
polymer molecules with low molecular weights are
small in size and, hence, can easily penetrate into
the wood structure [9, 10].
We studied the protective properties of the SDB
copolymer with 10 10 20-mm birch wood samples
dried to 8 10% moisture content.
The samples were weighed, immersed in a solu-
tion of SDB copolymer, and kept there for appropriate
time. The impregnated birch samples were taken from
the bath, dried, quenched, and weighed. The copoly-
mer content in the samples was estimated gravimet-
rically, from the mass gain.
The penetrability of a SDB copolymer solution
is strongly dependent on its concentration and im-
pregnation temperature. The influence exerted by
these factors deserves consideration, as at low tem-
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PROCESSING OF ACETOPHENON BOTTOMS FROM DISTILLATION OF STYRENE
1293
Table 3. Experimental design
B
A
b1 = 20
b2 = 40
b3 = 60
b4 = 80
a1 = 3
a2 = 8
a3 = 13
a4 = 18
c1 = 1, d1 = 90
y , y , y
c2 = 3, d2 = 120
y , y , y
c3 = 5, d3 = 150
y , y , y
c4 = 7, d4 = 180
y , y , y
1
1
1
2
2
2
3
3
3
4
4
4
c2 = 3, d3 = 150
y , y , y
c1 = 1, d4 = 180
y , y , y
c4 = 7, d1 = 90
y , y , y
c3 = 5, d2 = 120
y , y , y
5
5
5
6
6
6
7
7
7
8
8
8
c3 = 5, d4 = 180
y , y , y
c4 = 7, d3 = 150
c1 = 1, d2 = 120
c2 = 3, d1 = 90
y , y , y
y , y , y
y , y , y
9
9
9
10 10 10
11 11 11
12 12 12
c4 = 7, d2 = 120
y , y , y
c3 = 5, d1 = 90
c2 = 3, d4 = 180
c1 = 1, d3 = 150
y , y , y
y , y , y
y , y , y
1
3
13 13
14 14 14
15 15 15
16 16 16
Note: (y ) Water absorption, %; (y ) radial swelling, %; and (y ) tangential swelling, %.
i
i
i
peratures (10 30 C) and high concentrations (over
0 wt %) the impregnating solution based on SDB
for water resistance
6
5
copolymer is highly viscous, which complicates its
use. Raising the temperature decreases the viscosity
and significantly improves the penetrability of impreg-
nating solutions into the wood structure. However,
at SDB copolymer concentrations above 80%, even
elevated temperatures do not afford high impregnation
efficiency. The SDB copolymer solution was prepared
using a mixed 4 : 1 xylene acetone solvent. The
optimal concentration of the SDB copolymer solution
is not higher than 60 wt % [11]. This affords favorable
properties of the impregnating solutions and their
penetration into wood via diffusion. In view of the
aforesaid, we fixed the SDB copolymer concentra-
tion at 43 wt % and varied the impregnation tempera-
ture from 20 to 80 C. The main relationships in im-
pregnation of the birch wood samples were studied by
the fouth-order Greek Latin square design [12]. As
the principal factors most strongly affecting the prop-
erties of the resulting modified wood we chose im-
pregnation time, min (factor A); impregnation tem-
perature, C (factor B); heat treatment time, h (fac-
tor C); and heat treatment temperature, C (factor D)
of the samples being impregnated. The above-cited
factors are presented in Table 3.
y = 3.726 10 (36.9
0.638a)(43.9
0.254b)
(
38.9
1.98c)(18.0 + 0.0913d),
(9)
for radial swelling
3
y = 5.278 10 (6.78
0.0958a)(6.06
0.00605b)
(
6.79
0.254c)(5.34 + 0.003d),
(10)
for tangential swelling
3
y = 2.262 10 (8.64 0.0952a)(8.62 0.0192b)
(8.51
0.217c)(8.35
0.054d),
(11)
and after a 30-day period,
6
y = 2.868 10 (73.6
0.306a)(71.2
0.0156b)
(
72.0
0.399c)(73.7 + 0.0246d),
(12)
3
y = 1.656 10 (9.38
0.087a)(8.53
0.0016b)
(13)
(
9.47 0.249c)(8.49 + 0.0003d),
4
y
= 8.267 10 (12.2
0.144a)(10.7
0.0007b)
(14)
After computer processing of the experimental da-
ta, we obtained the regression equations (9) (14) de-
scribing the water resistance of the birch samples
treated with the SDB copolymer solutions as in-
fluenced by the main process parameters of impregna-
tion. The regression equations for the response func-
tions y, y , and y , %, have the following form: after
a 1-day period
(
10.7 + 0.0005c)(11.4
0.0055d).
The calculated and experimental data for the mod-
ified birch wood samples are presented in Table 4.
Our results show that the optimal conditions for
birch wood modification are as follows: impregnation
RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol. 75 No. 8 2002

1294
FILIMONOVA, NIKULIN
Table 4. Experimental and calculated water resistance
B
A
b1
b2
b3
b4
found
calculated
found
calculated
found
calculated
found
calculated
1
-day treatment
Water absorption, %
a1
a2
a3
a4
57.3
46.2
35.5
10.9
48.9
48.0
41.3
26.6
39.1
37.4
52.9
45.1
41.9
50.7
28.5
24.3
29.7
18.9
44.8
36.1
34.4
22.3
32.6
30.8
18.7
46.7
6.2
26.5
23.4
21.7
26.1
23.8
Radial swelling, %
a1
a2
a3
a4
9.0
6.2
4.8
3.5
7.5
6.6
5.6
4.5
7.5
6.4
7.0
5.8
6.9
7.1
4.9
4.8
4.1
4.9
6.6
6.0
6.2
5.1
6.2
5.4
6.4
7.3
3.5
5.9
5.6
5.6
5.5
5.6
Tangential swelling, %
a1
a2
a3
a4
11.5
8.5
7.2
4.9
10.2
8.7
7.6
7.0
9.5
8.0
9.8
9.0
9.0
8.6
6.9
7.2
5.6
7.2
8.0
6.7
7.9
7.3
8.0
6.8
7.2
9.4
5.0
7.6
6.9
7.2
7.3
7.0
3
0-day treatment
Water absorption, %
a1
a2
a3
a4
80.6
72.8
65.3
60.0
80.3
79.3
77.4
73.4
70.3
68.1
79.0
74.5
79.9
80.6
75.5
73.3
67.1
68.3
77.3
69.9
79.4
75.4
77.0
75.9
71.0
78.1
61.9
65.9
78.9
76.6
75.1
75.7
Radial swelling, %
a1
a2
a3
a4
10.8
9.3
7.7
6.1
10.1
9.1
8.2
7.2
9.5
8.5
8.9
8.0
9.5
9.6
7.6
7.7
7.9
8.2
9.6
8.8
8.9
8.0
9.1
8.1
8.4
8.9
7.2
8.5
8.4
8.5
8.5
8.6
Tangential swelling, %
a1
a2
a3
a4
12.9
10.9
9.6
12.1
11.0
10.2
9.8
11.9
10.2
12.1
10.7
11.9
10.9
10.3
9.9
10.8
11.7
11.4
10.5
9.4
11.8
10.7
9.0
11.5
11.2
10.6
9.6
12.1
10.9
9.8
8.2
10.0
time 18 min, impregnation temperature 80 C, and heat
treatment temperature and time 150 C and 7 h, re-
spectively.
that, in the examined temperature range, dehydration
of maleic acid into maleic anhydride dominates.
The resulting maleic anhydride participates in co-
polymerization.
CONCLUSIONS
(2) With the copolymer as impregnating composi-
(
1) A study of the kinetics of the reactions between
tion, wood can be efficiently protected against mois-
ture and water, since most of the macromolecules con-
styrene distillation bottoms and maleic acid showed
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PROCESSING OF ACETOPHENON BOTTOMS FROM DISTILLATION OF STYRENE
1295
tained in the copolymer have significantly smaller
sizes than wood micropores and easily penetrate into
the wood structure during impregnation.
Fizicheskaya khimiya (Physical Chemistry), Moscow:
Vysshaya Shkola, 1982.
8. Cross, A.D., An Introduction to Practical Infra-Red
Spectroscopy, London: Butterworths, 1960.
REFERENCES
9
. Ugolev, B.N., Drevesinovedenie s osnovami lesnogo
tovarovedeniya (Wood Science with Wood Merchan-
dizing Basics), Moscow: Lesnaya Promyshlennost’,
1
. Nikolaev, A.F. and Gal’perin, M.V., Vysokomol.
Soedin., Ser. B, 1969, vol. 11, no. 1, pp. 15 21.
. JPN Patent 56 55410.
. USSR Inventor’s Certificate, no. 755801.
. USSR Inventor’s Certificate, no. 622819.
. USSR Inventor’s Certificate, no. 1452812.
1
986.
2
3
4
5
6
1
1
0. Perelygin, L.M., Stroenie drevesiny (Wood Structure),
Moscow: Lesnaya Promyshlennost’, 1954.
1. Sakhokiya,I.A., Nikulin, S.S., and Dmitrenkov, A.I.,
Proizv. Ispol’z. Elastom., 2000, no. 3, pp. 20 23.
. Denisov, E.T., Kinetika gomogennykh khimicheskikh
reaktsii (Kinetics of Homogeneous Chemical Reac-
tions), Moscow: Vysshaya Shkola, 1988.
12. Akhnazarova, S.L. and Kafarov, V.V., Optimizatsiya
eksperimenta v khimii i khimicheskoi tekhnologii (Ex-
periment Optimization in Chemistry and Chemical
Technology), Moscow: Vysshaya Shkola, 1978.
7
. Godnev, I.I., Krasnov, K.S., Vorob’ev, N.K., et al.,
RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol. 75 No. 8 2002