Reinforcement paper with eucalyptus nanofibers or eucalyptus nanocrystals

1. Reinforcement paper with eucalyptus nanofibers or eucalyptus nanocrystals IñakiUrruzola, Eduardo Robles, Luis Serrano, M. Ángeles Andrés, JalelLabidi Department of Chemical and Environmental Engineering. University of the Basque Country, Pza. Europa 1, 20018 San Sebastián, Spain jalel.labidi@ehu.es

2. PREPARATION OF FIBRES Cutthe fibres in aMill Retsch2000 Sieve= 4mm MERCERIZATION 100ml NaOH (7,5%) + 5g fibre (1/20) T = 120 ºC t = 90min BLEACHING 2,27ml NaClO2 + 7,73ml H2O + 1g fibre pH=4, t= 2h, T=75 ºC Objectives • Elaborate paper by hot pressing and reinforce it with eucalyptus cellulose fibers using different concentration of nanofibersor nanocrystals. • Chemical and mechanical treatments have been used to obtain cellulose nanofibers and nanocrystals, using eucalyptus as raw material Extraction of bleached eucalyptus pulp Composition of the raw material and the bleached eucalyptus pulp EUKALYPTUS BLEACHED PULP

3. Extraction of nanofibers and nanocrystals Characterization AFM X-ray Diffraction (XRD) Fourier transforms infrared spectroscopy (FT-IR) • NanofibersNanocrystals • a)Eucalyptus ; b) Bleached pulp ; • c) Nanofibers; d) Nanocrystals • a) Nanocrystals; b) Nanofibers; c) Bleached pulp • FT-IR spectra shows that the vibration signal characteristic of lignin, 1735 cm-1, is disappeared obtaining pulp rich in cellulose. AFM images shows that Chemical and mechanical treatments have been reduced the fibers size significantly. X-ray patterns demonstrate that nanocrystals were obtained as crystallinity is increased three times for this sample. HYDROLYSIS 8.75ml H2SO4 (32%) + 1g FMA T = 45 ºC t = 60min HOMOGENIZATION 40 passes 1000 bar Nanocrystals EUCALYPTUS BLEACHED PULP HOMOGENIZATION 40 passes 1000 bar Nanofibers

4. Elaboration of papers • Homogenized solutions were vacuum filtered through a 0.22 μm nylon filter to obtain a homogeneous gel. • The gel was placed between two copper plates in a Santechydropneumatic molding press (30 tons), and four cycles were performed increasing pressure at constant temperature to avoid shape malformations in the paper due that may occur with high pressure. • The cycles were performed at 10, 20, and 40 bar at 100 ºC and curing pressure of 200 bar at 100 ºC was carried out for 25 minutes. Mechanical properties • Obtained results showed that the addition of cellulose nanofibers affected slightly the mechanical properties. All the propertiesshowed better performance as the percent of cellulose nanocrystal increased.

5. Acknowledgements Thank you for your attention