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Carboxylated cellulose is an important material in industry. The most well-known example is the
carboxymethylcellulose (CMC) which is wildly used in industry in numerous applications as paper industry or
pharmacology. Nevertheless, the major disadvantage of CMC is its synthesis using monochloracetic acid,
which is corrosive, toxic, and harmful to environment and classified as extremely hazardous substance.
In this project, an innovative approach is applied to make cellulose functionalized with carboxylic
acid groups as a functional substitute for CMC, by combination of renewable resources and benign
reactants.
Two main goals were established: alternative synthesis of carboxylated cellulose with low and high
degree of substitution. Two methods were developed: an heterogeneous approach on the surface with solvents
able to swell cellulose fibers and an homogeneous approach in solution with solvent able to dissolve cellulose.
For each method, both acetalization of ethyl levulinate or transacetalization of ketal of ethyl levulinate were
tested. Transacetalization was more efficient than direct acetalization.
After reaction, samples were characterized using various methods. To see if reactions were
successful, samples were analyzed using infrared spectroscopy, looking for characteristic signals of acetalized
cellulose. The thermogravimetric analysis (TGA) was also used to measure the behavior of samples depending
of temperature. Acetalized cellulose was hydrolyzed in basic solution in order to obtain the carboxylated
cellulose. To get a quantitative idea about the carboxylate content Dynamic Vapour Sorption (DVS) and
titration were used. All those characterizations tend to prove that a new method of carboxylation of cellulose
with ethyl levulinate was successfully developed.
In conclusion, this project allowed to prove the concept of carboxylation of cellulose using ethyl
levulinate derivatives and opens new opportunities to replace CMC. However, lot of work is still need to be
done, especially concerning achievement of high modification degrees in green reaction media, applications
and characterizations of products.
Carboxylated cellulose is an important product on the market, and one of the most well-known examples is carboxymethylcellulose (CMC). However, CMC is prepared by modification of cellulose with the extremely hazardous compound monochloracetic acid. In this project, we want to make a carboxylated cellulose that is a functional equivalent for CMC using a greener process with renewable raw materials derived from levulinic acid. Processes to achieve cellulose with a low and a high carboxylation degree will be designed.