Use of kraft lignin as filler for starch films
Films containing 0–30% of commercial kraft lignin mixed with wheat starch were obtained by extrusion followed by thermal moulding. The influence of lignin content on the film mechanical properties was evaluated by stress-strain tests run at two ambient relative humidity levels. At 58% relative humid...
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Published in | Polymer degradation and stability Vol. 59; no. 1; pp. 273 - 277 |
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Main Authors | , , , |
Format | Journal Article Conference Proceeding |
Language | English |
Published |
Oxford
Elsevier Ltd
1998
Elsevier Science Elsevier |
Subjects | |
Online Access | Get full text |
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Summary: | Films containing 0–30% of commercial kraft lignin mixed with wheat starch were obtained by extrusion followed by thermal moulding. The influence of lignin content on the film mechanical properties was evaluated by stress-strain tests run at two ambient relative humidity levels. At 58% relative humidity and up to 20% lignin, a very slight increase of elongation and stress at break was observed. At 71% relative humidity and up to 30% lignin, the film resistance to elongation significantly decreased, compared to the control starch film. Dissolution tests and water sorption isotherms showed that lignin actually reduces the overall water affinity of the films. These results are consistent with the hypothesis of a twophase material consisting of a hydrophilic starch matrix filled with hydrophobic lignin aggregates, as confirmed by microscopic observations. Casting experiments showed that the lower molecular weight fraction of kraft lignin may be responsible for a slight plastification of starch. |
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ISSN: | 0141-3910 1873-2321 |
DOI: | 10.1016/S0141-3910(97)00193-6 |