Abstract
The degradation of paper-based materials involves several and complex mechanisms, such as hydrolysis and oxidation. The behaviour of different types of pulps can be very variable. In this study, the difference upon oxidation of contemporary non-recycled and recycled papers, which now constitute a considerable fibre source, is investigated. A 0.015 M potassium periodate solution is used to oxidise five types of paper, two non-recycled and three recycled, for 0.5, 1, 2 and 4 h. The effects of such oxidation treatments are evaluated in terms of carbonyl content and degree of polymerisation (DP). A modified procedure of the Szabolcs’s method and viscometry are used to measure the carbonyl content and DP, respectively. The carbonyl groups are found to increase more rapidly in the recycled papers than in the non-recycled ones. On the contrary, oxidation causes a larger decrease of the DP values in the non-recycled papers, the paper made of pure cellulose being the most sensitive in terms of depolymerisation. The DP values measured for pure cellulose paper are in line with previously reported data. Moreover, in accordance with the Ekenstam equation, the plots of the reciprocal of DP as a function of oxidation time show good linear correlations for all types of paper investigated. Pseudo rate constants are thus calculated from the slopes of these plots, those of the non-recycled papers being found to be higher than those of the recycled papers.Graphic abstract
Highlights
Technologies and raw materials for papermaking have radically changed over the centuries (Hunter 1978)
The carbonyl content increases, and the degree of polymerisation (DP) decreases with increasing oxidation time
The present results indicate that oxidation influences the chemical properties (degree of polymerisation (DP) and carbonyl content) of the investigated paper types to different extents, stimulating further work to study these different behaviours
Summary
Technologies and raw materials for papermaking have radically changed over the centuries (Hunter 1978). Unlike the well-studied Western historical paper for which significant research has been carried out over the past decades, scientific research on contemporary recycled paper is quite limited It has previously been reported (Coppola et al 2018a) that accelerated degradation experiments, carried out exposing recycled and non-recycled papers to extreme conditions of temperatures (50–80 °C) and relative humidity levels (26–98%), led to a systematic difference between the degradation rates of the recycled and non-recycled paper, albeit negligible considering the experimental limits. This finding could be traced back to a different extent of oxidative degradation. In the present study, the extents of oxidative degradation in different papers are evaluated measuring its effects on DP in order to give insight into the behaviour of contemporary recycled and non-recycled paper upon oxidation
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
