Compression molded wood pulp biocomposites: A study of hemicellulose influence on cellulose supramolecular structure and material properties
2012 (English)In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 19, no 3, 751-760 p.Article in journal (Refereed) Published
In this study, the importance of hemicellulose content and structure in chemical pulps on the property relationships in compression molded wood pulp biocomposites is examined. Three different softwood pulps are compared; an acid sulfite dissolving grade pulp with high cellulose purity, an acid sulfite paper grade pulp and a paper grade kraft pulp, the latter two both containing higher amounts of hemicelluloses. Biocomposites based the acid sulfite pulps exhibit twice as high Young's modulus as the composite based on paper grade kraft pulp, 11-12 and 6 GPa, respectively, and the explanation is most likely the difference in beating response of the pulps. Also the water retention value (WRV) is similarly low for the two molded sulfite pulps (0.5 g/g) as compared to the molded kraft pulp (0.9 g/g). The carbohydrate composition is determined by neutral sugar analysis and average molar masses by SEC. The cellulose supramolecular structure (cellulose fibril aggregation) is studied by solid state CP/MAS 13C-NMR and two forms of hemicellulose are assigned. During compression molding, cellulose fibril aggregation occurs to higher extent in the acid sulfite pulps as compared to the kraft pulp. In conclusion, the most important observation from this study is that the difference in hemicellulose content and structure seems to affect the aggregation behaviour and WRV of the investigated biocomposites.
Place, publisher, year, edition, pages
2012. Vol. 19, no 3, 751-760 p.
Chemical pulps, Composites, Compression molding, CP/MAS 13C-NMR, Fibril aggregation, Hemicelluloses, Mechanical properties, Aggregation behaviours, Average molar mass, Bio-composites, Content and structure, CP/MAS 13
C-NMR, Material property, Neutral sugar analysis, Paper grade pulp, Softwood Pulps, Supramolecular structure, Water retention value, Wood pulp, Young's Modulus, Chemical pulp, Composite materials, Kraft process, Kraft pulp, Paper and pulp mills, Paper products, Pulp beating, Sugars, Sulfite pulp, Wood, Cellulose, Agglomeration, Sulfite Pulps
Paper, Pulp and Fiber Technology
IdentifiersURN: urn:nbn:se:kth:diva-95695DOI: 10.1007/s10570-012-9688-2ISI: 000303459200017ScopusID: 2-s2.0-84860387690OAI: oai:DiVA.org:kth-95695DiVA: diva2:529332
QC 201506302012-05-302012-05-292015-06-30Bibliographically approved