Verfahren zur Herstellung von Cellulose-Derivaten

摘要

According to the invention, samples of highly crystalline (>80 %) technical cellulose with a degree of polymerisation of approximately 1500 were enzymatically pre-treated with commercial endoglucansases under various conditions before being chemically converted to substituted cellulose derivatives. Said enzymatically pre-treated cellulose samples showed a significantly (up to 222 %) higher degree of substitution compared with control samples which had been pre-treated with buffer without enzymes. The increase in substitution during the chemical reaction was observed in the presence of various quantities of alkali, but decreased with reduced quantities of alkali. It was possible to significantly reduce the quantity of alkali required (by 60 %) and still obtain the same degree of substitution by using the cellulose samples which had been pre-treated with endoglucanase compared with the cellulose samples which had been pre-treated with buffer only. It was also possible to further increase the substitution of the enzymatically pre-treated cellulose samples by reducing the proportion of water in the reaction mixture used in the chemical reaction.