ISSN 1070-4272, Russian Journal of Applied Chemistry, 2016, Vol. 89, No. 1, pp. 155−159. © Pleiades Publishing, Ltd., 2016.
Original Russian Text © S.M. Krutov, E.V. Ipatova, D.S. Kosyakov, N.V. Shkaeva, E.M. Korotkova, A.V. Pranovich, S. Willför, 2016, published in Zhurnal Prikladnoi
Khimii, 2016, V
ol. 89, No. 1, pp. 128−133.
AND POLYMERIC MATERIALS
Lignopolyurethane Foam Based on Hydrolytic Lignin
S. M. Krutov
, E. V. Ipatova
, D. S. Kosyakov
, N. V. Shkaeva
, E. M. Korotkova
A. V. Pranovich
, and S. Willför
Kirov State University of Forestry Engineering, Mirgorodskaya ul., 26–28, St. Petersburg, 191024 Russia
Lomonosov Northern (Arctic) Federal University, nab. Severnoi Dviny 17, Arkhangelsk, 163002 Russia
Abo Akademi University, Tuomiokirkontori 3, Turku, FI-20500 Finland
Received December 25, 2015
Abstract—Synthesis of lignopolyurethane foams based on wastes from biochemical industries, both freshly obtained
technical-grade hydrolytic lignins and those stored in dumps for a long time, was studied. It was found out that the
lignopolyurethane foams obtained have high heat-insulating properties conforming to the standards of heat-insulating
materials. It was shown for the ﬁ rst time that prolonged storage under atmospheric conditions of technical-grade
hydrolytic lignin contained in lignopolyurethane foams has no signiﬁ cant effect on their physicomechanical properties.
Lignopolyurethane foams widely used as heat- and
sound-insulating materials, including biodegradable co-
polymers based on vegetable and synthetic raw materials
are of particular interest at present [1, 2].
The use of large-scale wastes formed in chemical
processing of renewable vegetable raw materials, such
as technical-grade lignins, is promising in this regard.
As lignin is a polymer containing a noticeable amount
of hydroxy (phenolic and aliphatic) and carboxy groups
including reactive hydrogen, it can enter into reactions
with polyisocyanates to give polyurethanes.
Various kinds of technical-grade lignin are used to
obtain lignopolyurethane foams: kraft lignin, lignin
formed in steam-explosion hydrolysis, organosolv lignin,
water-soluble lignosulfonates formed in sulﬁ te cellulose
cooking [3–8, 10]. Scheme 1 shows the hypothetical
chemical structure of lignopolyurethane foam based on
Depending on the synthesis conditions, nature, and
relative amounts of the starting components, lignopoly-
urethanes can be used as heat-insulating materials, glues,
coatings, etc. . The production cost of lignopolyure-
thane formulations is 40–45% lower than that of ordinary
Introduction of technical-grade lignins into polyure-
thane foams can improve their mechanical properties,
thermal stability, moisture resistance, and other charac-
teristics [6, 7, 9]. The presence of phenolic structures also
implies the presence biocide properties.
It seems promising to study the possibility of obtaining
lignopolyurethane foams based on technical-grade
lignin, used large-scale waste formed in the biochemical
processing of wood.
This approach is based on the presence of hydroxy
groups of varied nature (aromatic, aliphatic, carboxylic,
etc.) in the structure of lignin, which can enter into
polycondensation reactions with di- or polyisocyanates,
with urethane groups –HN–CO–O– formed [7, 9, 11]:
We studied the possibility of obtaining lignopolyure-
thane foams based on hydrolytic lignin from the presently
operating Kirov BioChemPlant and other plants.
Hydrolytic lignin from Kirov BioChemPlant was dried
at room temperature and sieved (particle size 0.25 mm).
Polyol, triethylene glycol (1.124 g mL
at 20°C), and