Soft, highly swelling fibres by alkali-activated chemical modification

PI: Per Larsson, Lars Wågberg, Gunnar Westman
PhD Student: Johanna Sjölund, KTH
Duration: 4 years starting autumn 2021

Intro________________________________________________________________________________________________________________

To make cellulosic fibres more flexible and malleable the components inside the fibre must be properly modified, that is, the cellulose, lignin or hemicellulose needs to be at least partially transformed into a proper derivative. This project aims to functionalize cellulose with ether bonded cationic groups. Such modifications can be obtained by reacting an epoxide reagent, commonly epoxypropyltrimethylsmmonium chloride (EPTMAC), with alkali-activated hydroxyl groups on the cellulose backbone, resulting in fibres carrying a net cationic charge in the case of EPTMAC. While some studies have been carried out on wet, swollen fibres the dry properties of these modified fibres, and in particular their thermomechanical properties, have not been studied in greater detail. Therefore, this project will study the structure–property relationship of a set of different fibres which have been subjected to cationization with EPTMAC. Furthermore, the project will fundamentally study the modification process and investigate how the starting material, its pretreatment and the reaction conditions affect its efficiency. 

Objectives_________________________________________________________________________________________________________
 
Scientific: Establish the influence of initial fibre structure on chemical modification (by etherification) and the structure -property relationship of material formed from these fibres.

Technical: Identify the best starting material and modification protocol for alkali-activated chemical modification of cellulose.

Description of how this project addresses the hypotheses in FibRe   __________________________________________                          
This project relates Hypothesis 2, where delignified fibres are modified to make the fibre thermoplastic and thermoprocessable. Furthermore, the project will shed light on how the composition and structure of the delignified fibre influences the accessibility and efficiency of the modification, which is valuable knowledge that can be used also for other types of chemical modifications.

Page manager Published: Tue 07 Dec 2021.