Teknisk- naturvetenskaplig fakultet UTH-enheten
Besöksadress:
Ångströmlaboratoriet Lägerhyddsvägen 1 Hus 4, Plan 0
Postadress:
Box 536 751 21 Uppsala
Telefon:
018 – 471 30 03
Telefax:
018 – 471 30 00
Hemsida:
http://www.teknat.uu.se/student
Abstract
Prediction of elastic properties of nanofibrillated cellulose and microcrystalline cellulose
Astrid Berghult, Signe Sidwall Thygesen, Camilla Öhman
The mechanical properties of a composite, filler and matrix, are affected by the stress transfer ability of the material that constitutes the composite. The aim of this project was to analyse stiffness of the filler, in this case microcrystalline cellulose (MC) and nanofibrillated cellulose (NFC). The stiffness was derived from back-calculations on mathematical models for the whole composite, and not from experimental data. This approach was used due to difficulties of measuring the small dimensioned fibrils in a tensile test. As in earlier literature, it was confirmed that MC has a lower stiffness than NFC. The results also show that the amount of fibrils mixed into the composite has an effect on the overall stiffness of the material and that the volume fraction for MC should be higher than the 10% used in this research. It was concluded that the stiffness of NFC ranges between 20 and 50 GPa. All the models that were used, Cox, Tsai Laminate, Hashin and Halpin- Tsai gave reasonable values for stiffness of NFC, for MC the volume fraction had to exceed 10% to produce a reasonable value.
ISSN: 1401-5757, UPTEC F** ***
Examinator: Martin Sjödin, Maria Strømme Ämnesgranskare: Daniel Carlsson
Handledare: Gabriella Josefsson
