Sökning: "carboxymethylation"
Visar resultat 1 - 5 av 11 avhandlingar innehållade ordet carboxymethylation.
1. Microfibrillated cellulose : Energy-efficient preparation techniques and key properties
Sammanfattning : This work describes three alternative processes for producing microfibrillated cellulose (MFC) in which pulp fibres are first pre-treated and then homogenized using a high-pressure homogenizer. In one process, fibre cell wall delamination was facilitated with a combined enzymatic and mechanical pre-treatment. LÄS MER
2. Microfibrillated cellulose: Energy-efficient preparation techniques and applications in paper
Sammanfattning : This work describes three alternative processes for producing microfibrillated cellulose (MFC; also referred to as cellulose nanofibrils, CNF) in which bleached pulp fibres are first pretreated and then homogenized using a high-pressure homogenizer. In one process, fibre cell wall delamination was facilitated by a combined enzymatic and mechanical pretreatment. LÄS MER
3. The effects of cellulosic fiber charges on polyelectrolyte adsorption and fiber-fiber interactions
Sammanfattning : The surface charges of cellulosic fibers contribute to several papermaking operations that influence the manufacture and final properties of paper. This thesis investigates the effect of the surface charges on wet-end chemistry, e.g. LÄS MER
4. Dried nanofibrillated cellulose and its bionanocomposites
Sammanfattning : During the past decade there has been a growing interest in the reinforcement of synthetic polymers with cellulose nanowhiskers and nanofibrillated cellulose (NFC) obtained from plants or bacteria. Their beneficial mechanical properties like high stiffness and strength, in combination with their low mass allowed successful reinforcement of water based polymer dispersions (latexes) for the production of solution cast composite films. LÄS MER
5. Mercerization and Enzymatic Pretreatment of Cellulose in Dissolving Pulps
Sammanfattning : This thesis deals with the preparation of chemically and/or enzymatically modified cellulose. This modification can be either irreversible or reversible. Irreversible modification is used to prepare cellulose derivatives as end products, whereas reversible modification is used to enhance solubility in the preparation of regenerated cellulose. LÄS MER