Dissolution of Various Cellulosic Materials and Effect of Regenerated Cellulose on Mechanical Properties of Paper

摘要

Recycling of paper materials or other type of cellulose fibres is important regarding saving of nature resources and environmental protection. Cellulose dissolution and regeneration from various materials is one of the recycling possibilities. Cellulose dissolution by NaOH/urea system has a great potential due to the use of harmless reagents, and at the same time it is challenging due to the formation of gel-like substances when cellulose has degree of polymerization of more than 1000. It was found that macrocrystalline cellulose and cotton cellulose were dissolved in NaOH/urea, but tissue paper, filter paper and waste paper were not dissolved completely. Additives of kraft pulp and pulp waste that was dissolved and regenerated from NaOH/urea and cupriethylendiamine (CuETD) increased mechanical properties of paper sheet when added in amounts of 0-30 % to paper composition. CuETD additive was more effective than NaOH/urea additive; however, the latter has potential for further research as it is environmentally friendlier.