Search for dissertations about: "carboxymethylation"

Showing result 1 - 5 of 11 swedish dissertations containing the word carboxymethylation.

  2. 1. Microfibrillated cellulose : Energy-efficient preparation techniques and key properties

    Author : Mikael Ankerfors; Lars Wågberg; Minna Hakkarainen; Paul Gatenholm; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Microfibrillated cellulose; microfibrillar cellulose; nanofibrillated cellulose nanofibrillar cellulose; nanocellulose; MFC; NFC; production techniques; energy efficient; gel properties; films; enzymes; carboxymethylation; carboxymethyl cellulose; CMC; mechanical properties; oxygen barrier; homogenization;

    Abstract : 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. READ MORE

  4. 2. Microfibrillated cellulose: Energy-efficient preparation techniques and applications in paper

    Author : Mikael Ankerfors; Lars Wågberg; Akira Isogai; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Microfibrillated cellulose; microfibrillar cellulose; nanofibrillated cellulose; nanofibrillar cellulose; cellulose nanofibrils; nanocellulose; MFC; NFC; CNF; production techniques; energy efficient; gel properties; films; enzymes; carboxymethylation; carboxymethyl cellulose; CMC; mechanical properties; oxygen barrier; homogenization; linting; papermaking; Fiber- och polymervetenskap; Fibre and Polymer Science;

    Abstract : 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. READ MORE

  5. 3. The effects of cellulosic fiber charges on polyelectrolyte adsorption and fiber-fiber interactions

    Author : A. Elisabet Horvath; Lars Wågberg; Stefan Zauscher; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; adsorption; electrolyte; polyelectrolyte; polyelectrolyte titration; stoichiometry; fluorescence; CLSM; carboxymethylation; ESCA; charge ration; colloidal interactions; mechanical forces; network strength; floc; CPM; rehometer; Cellulose and paper engineering; Cellulosa- och pappersteknik;

    Abstract : 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. READ MORE

  6. 4. Dried nanofibrillated cellulose and its bionanocomposites

    Author : Christian Eyholzer; Olli Ikkala; Luleå tekniska universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Trä och bionanokompositer; Wood and Bionanocomposites;

    Abstract : 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. READ MORE

  7. 5. Mercerization and Enzymatic Pretreatment of Cellulose in Dissolving Pulps

    Author : Heléne Almlöf Ambjörnsson; Ulf Germgård; Thomas Nilsson; Storker Moe; Karlstads universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; alkali; carboxymethyl cellulose; cellulose I; cellulose II; cellulose dissolution; degree of substitution; enzymatic treatment; filterability; gel formation; mercerization; multivariate analytical methods; NIR FT Raman spectroscopy; sodium hydroxide; zink oxide; Chemical Engineering; Kemiteknik;

    Abstract : 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. READ MORE