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Visar resultat 1 - 5 av 239 avhandlingar som matchar ovanstående sökkriterier.
1. Processing and properties of thermoplastic composites containing cellulose nanocrystals or wood-based cellulose fibres
Sammanfattning : Cellulose nanocrystals (CNC) were surface modified with dialkylamines to increase the compatibility between the CNC and the polymeric matrix, and promising results were obtained, with a 300 % stiffness increase when the mixed dispersion was compression moulded on a laboratory scale. The manufacturing process was up-scaled using water-assisted mixing in a twin-screw extruder (TSE) followed by a second compounding step and injection moulding (IM). LÄS MER
2. Additive-Driven Improvements in Interfacial Properties and Processing of TMP-Polymer Composites
Sammanfattning : Efforts to address environmental concerns have resulted in new regulations designed to plan the reduction of plastic and synthetic polymer usage, necessitating the search for sustainable natural alternatives with comparable cost-effectiveness and mechanical performance. Thermomechanical pulp (TMP) fibres are one of the most affordable natural fibres that have no chemical refining in production, production have a high yield of 90-98% and TMP fibres have been demonstrated to improve the mechanical characteristics (strength, stiffness and toughness) of wood-polymer composites (WPCs) compared to the pure polymer. LÄS MER
3. 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
4. Laboratory method for the study of moisture-induced waviness in paper
Sammanfattning : Paper that is subjected to moisture undergoes dimensional changes. It expands during moistening and shrinks during drying. When the paper is under tension between rollers, the effects are complex since shrinkage and expansion are restricted in the width direction. Waves can then appear on the paper web. LÄS MER
5. Engineering of lignin in wood towards functional materials
Sammanfattning : Through 270 million years of evolution, the finely tuned hierarchical structure of wood has been optimized for efficient nutrient transport and exceptional mechanical stability. Its distinctive orthotropic constitution can provide inspiration and design opportunities for the development of novel functional materials. LÄS MER