Application of the Solvent Dimethyl Sulfoxide/Tetrabutyl-
Ammonium Acetate as Reaction Medium for Mix-Acyla-
tion of Pulp
YONGQI YU, ZEMING JIANG, JIAOJIAO MIAO, YANG LIU, LIPING ZHANG
MOE Engineering Research Center of Forestry Biomass Materials and Bioenergy, Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing
Forestry University, No. 35 Tsinghua East Road, Haidian District, Beijing 100083, China
Correspondence to: Liping Zhang; e-mail: zhanglp418@163.com.
Received: March 28, 2016
Accepted: June 20, 2016
ABSTRACT:
An important cellulose mixed ester, cellulose acetate butyrate (CAB), was successfully prepared in tetrabutylam-
monium acetate (TBAA)/dimethyl sulfoxide (DMSO) system. The structure of the cellulose derivative was characterized with a
Fourier Transform IR spectrometer and analyzed using
13
C cross-polarization magic angle spinning nuclear magnetic resonance.
The degree of substitution (DS) of the samples prepared was calculated according to
1
H-NMR analysis. And the solubility of CAB
was investigated in a wide range of traditional organic solvents such as 2-methyl-ethyl ketone, dichloromethane and ethyl acetate.
The thermal properties of the product were analyzed by TGA analysis. The surface morphology of the esters was characterized
with a field emission-scanning electron microscopy (FE-SEM). The relationship among surface morphology, solubility, and DS of
the cellulose mixed ester was discussed. Moreover, TBAA and DMSO were recovered by vacuum distillation, which was character-
ized by Fourier transform infrared spectroscopy. © 2016 Wiley Periodicals, Inc. Adv Polym Technol 2018, 37, 21742; View this arti-
cle online at wileyonlinelibrary.com. DOI 10.1002/adv.21742
KEY WORDS:
Cellulose, Dimethyl sulfoxide, Mix-acylation, Tetrabutylammonium acetate
Introduction
T
he production of crude oil-based materials seems to be
limited with the declining availability of resources. For-
tunately, as the most abundant biopolymer, cellulose has been
generally considered a sustainable and promising raw mate-
rial for the modern chemical industry.
1
The amount of ligno-
cellulosic biomass generated by nature is close to 1.7 9 10
11
tons per year and cellulose is therefore nearly inexhaustible
resource.
2
Several million of cellulose derivative products are
produced each year, using wood with a cellulose content of
40–50% as principal raw material.
3
Cellulose is a very unique
polymer with interesting properties, for example, nice biocom-
patibility, low density but high strength and durability, high
thermal stability, and the ability to absorb moisture.
4,5
How-
ever, cellulose features some drawbacks as well, such as non-
melt processable, difficult to dissolve in common solvents and
water due to the numerous intermolecular and intramolecular
hydrogen bonds and partially crystalline structure in cellulose,
lack of thermoplasticity, poor crease resistance, and poor
dimensional stability.
2,6,7
For making cellulose more process-
able and applicable, its melting point should be reduced
below its decomposition temperature by means of esterifica-
tion, etherification, or polymer grafting. Through this process,
the intrinsic hydrogen bonding breaks down while interfering
with the crystalline nature of the polymer. Cellulose deriva-
tives can be prepared via modification of cellulose, which are
widely applied in food packaging materials, membrane prepa-
ration, and separation processes.
3,8
Therefore, it is greatly necessary to chemically modify cel-
lulose to tune and improve its properties for a desired applica-
tion.
9
After cellulose derivatization, not only the solubility
parameter is greatly improved, but also some novel physical
and chemical properties can be introduced. Esterification of
cellulose induces solubility and melts processability.
10
Nowa-
days, various cellulose derivatives, such as cellulose esters
and cellulose ethers, have been synthesized and commercial-
ized.
11
And cellulose esters are perhaps one of the oldest ther-
mal plastics in the chemical industry. Cellulose esters,
especially cellulose acetates (CA), cellulose acetate propionates
(CAP), and cellulose acetate butyrates (CAB), with a degree of
substitution (DS) in the range 2.5–3.0, typically have melting
temperatures in the 150–250°C range.
12
Their composite
mechanical properties are potentially comparable with
polypropylene composites.
13
Industrially, a typical CA pro-
duction consists of a sequence of two heterogeneous reactions,
namely functionalization of the polymer to a DS of 3, and
then followed by partial hydrolysis of the product to the
widely applied acetone-soluble CA with a DS of 2.5.
14
Advances in Polymer Technology, Vol. 37, No. 4, 2018, DOI 10.1002/adv.21742
© 2016 Wiley Periodicals, Inc.
21742 (1 of 7)
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