Fibre porosity development of dissolving pulp during mechanical and enzymatic processing

• Published in: Cellulose (London) Vol. 21; no. 5; pp. 3667 - 3676
• Main Authors: Grönqvist, S., Hakala, T. K., Kamppuri, T., Vehviläinen, M., Hänninen, T., Liitiä, T., Maloney, T., Suurnäkki, A.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-10-2014; Springer Nature B.V
• Subjects: Bioorganic Chemistry; Cellulose; Cellulose fibers; Ceramics; Chemistry; Chemistry and Materials Science; Composites; Dissolution; Glass; Hydrolysis; Natural Materials; Organic Chemistry; Original Paper; Physical Chemistry; Polymer Sciences; Porosity; Regeneration; Shredding; Sodium hydroxide; Sustainable Development; Zinc oxide; Cellulose dissolution; Porosity; Solute exclusion; Dissolving pulp; Enzymatic hydrolysis
• ISSN: 0969-0239; 1572-882X
• DOI: 10.1007/s10570-014-0352-x

Dissolving grade pulps are used as raw material for manufacture of regenerated cellulose fibres and their use is constantly growing. Despite intensive research, there is still a need to develop cellulose dissolution-regeneration processes that would be economically viable, fulfil the pre-conditions of sustainability and would be able to meet the strict product quality requirements. The basis for creation of such a process is in deep understanding of the biomass structure and factors affecting the cellulose modification and dissolution. In this paper, the effects of the mechanical and enzymatic pre-treatments on the pore structure and alkaline solubility of dissolving grade pulp are discussed. Formation of micro- and macropores in the pulp fibres during mechanical shredding was found to correlate with the susceptibility of the fibres to enzymatic hydrolysis. The fibre porosity development during the processing was studied by a modified solute exclusion approach, which revealed differences between the effect of mild enzyme or acid hydrolysis on the pore structure of fibres. The dissolution of the modified fibres in NaOH/ZnO was evaluated and found to correlate with overall pore volume and accessible surface area analysed by the modified solute exclusion method.