1070-4272/03/7607-1152$25.00C 2003 MAIK [Nauka/Interperiodica]
Russian Journal of Applied Chemistry, Vol. 76, No. 7, 2003, pp. 1152!1155. Translated from Zhurnal Prikladnoi Khimii, Vol. 76, No. 7,
2003, pp. 1185!1188.
Original Russian Text Copyright C 2003 by Nikulin, Filimonova, Oleinikova.
AND POLYMERIC MATERIALS
Modification of Styrene-Containing Oligomer Based on Bottoms
from Toluene Distillation in Production of Polybutadiene
S. S. Nikulin, O. N. Filimonova, and O. N. Oleinikova
Voronezh State Academy of Forestry Engineering, Voronezh, Russia
Voronezh State Technological Academy, Voronezh, Russia
Received November 27, 2002; in final form, April 2003
Abstract-Chemical modification of styrene-containing oligomer with maleic anhydride was studied. The
process conditions and content of maleic anhydride were optimized.
The main avenue in processing and utilization of
organic and polymeric wastes  is preparation
from them of oligmers by polymerization or degrada-
tion. However, low-molecular-weight polymers pre-
pared from petrochemical wastes and by-products,
as a rule, do not have the required set of properties,
which largely limits their application. Some charac-
teristics of substances obtained from petrochemical
wastes and by-products can be improved by modifica-
tion . An example of such modification can be
reaction with maleic anhydride (MA) [7, 8], allowing
introduction into oligomers of additional reactive
groups and imparting new properties to the products.
The goal of this work was to modify with maleic
anhydride the styrene-containing oligomer prepared
from bottoms of distillation of recycled solvent, tolu-
ene (TDB), in production of polybutadiene, and also
to examine the possibility of using the modified oligo-
mer as impregnating material for improving the prop-
erties of wood-fiber boards.
Modification experiments were performed with
TDB oligomer containing units of styrene (~75%),
4-vinylcyclohexene (VCH), 1,5,9-cyclododecatriene
(CDT), and n-2,4,6,10-dodecatetraene (NDT). The
viscosity-average molecular weight
of the oligomer
was about 1663.
Experiments were performed as follows. A steel
ampule was charged with a styrene-containing TDB-
based oligmer containing no more than 5 wt % re-
sidual low-molecular-weight products (dry residue
>95 wt %) and with MA. The reaction temperature
was 160oC. The MA content was varied from 3 to
7 wt % relative to the oligomer.
The reaction of MA with the oligomer was moni-
tored by intermittent sampling from the ampule, fol-
lowed by determination of the viscosity-average
molecular weight of the product
and of the acid
number (titration with alcoholic alkali to determine
the content of anhydride and carboxy groups ).
Experimental studies showed that the course of
modification of the TDB-based styrene-containing
oligomer depends on the MA content in the reaction
mixture (Fig. 1a). By computer treatment of the re-
sults, we obtained second-order equations describing
the influence of the process time and MA content on
the viscosity-average molecular weight
= 1578 3 34.43x + 0.92x
= 3.0 wt %;
= 1572 3 42.26x + 1.16x
= 5.0 wt %;
= 1634 3 69.38x + 2.06x
= 7.0 wt %.
All the curves pass through a minimum at the reac-
tion time of 17319 h. Then the molecular weight of
the oligomer starts to grow.
At a low content of MA in the reaction mixture (up
to 3.0 wt % relative to the oligomer), in the initial
stage of the process the viscosity and hence
ly decrease. This trend is particularly pronounced at
the reaction time of 17319 h. Longer (>19 h) reaction
results in the growth of the viscosity and hence
At the MA content increased to 537 wt % relative
to the oligomer, the degradation processes in the ini-
tial stage become less pronounced (Fig. 1a), as indi-
cated by the less pronounced decrease in the molecu-
lar weight of the modified oligomer.
The acid number (Fig. 1b) grows with increasing
synthesis time and MA dosage. This suggests predom-