Dynamic Nanocellulose Networks for Thermoset-like yet Recyclable Plastics with a High Melt Stiffness and Creep Resistance
Journal article, 2019
Many polymers, including polyethylene, feature a relatively low melting point and hence must be cross-linked to make them viable for applications that demand a high stiffness and creep resistance at elevated temperatures. The resulting thermoset plastics cannot be recycled, and therefore alternative materials with a reconfigurable internal network structure are in high demand. Here, we establish that such a thermoset-like yet recyclable material can be realized through the addition of a nanocellulose reinforcing agent. A network consisting of cellulose nanocrystals, nano- or microfibrils imparts many of the characteristics that are usually achieved through chemical cross-linking. For instance, the addition of only 7.5 wt % of either nanocellulose material significantly enhances the melt stiffness of an otherwise molten ethylene-acrylate copolymer by at least 1 order of magnitude. At the same time, the nanocellulose network reduces the meltcreep elongation to less than 10%, whereas the neat molten matrix would rupture. At high shear rates, however, the molten composites do not display a significantly higher viscosity than the copolymer matrix, and therefore retain the processability of a thermoplastic material. Repeated re-extrusion at 140 °C does not compromise the thermomechanical properties, which indicates a high degree of recyclability. The versatility of dynamic nanocellulose networks is illustrated by 3D printing of a cellulose composite, where the high melt stiffness improves the printability of the resin.
Author
Anna Peterson
Chalmers, Chemistry and Chemical Engineering, Applied Chemistry
Ida Östergren
Chalmers, Chemistry and Chemical Engineering, Applied Chemistry
Antiope Lotsari
Chalmers, Chemistry and Chemical Engineering, Applied Chemistry
Abhijit Venkatesh
Chalmers, Industrial and Materials Science, Engineering Materials
Johannes Thunberg
Chalmers, Industrial and Materials Science, Engineering Materials
Anna Ström
Chalmers, Chemistry and Chemical Engineering, Applied Chemistry
Ramiro Rojas
Royal Institute of Technology (KTH)
Wallenberg Wood Science Center (WWSC)
Martin Andersson
Chalmers, Chemistry and Chemical Engineering, Applied Chemistry
Lars A. Berglund
Royal Institute of Technology (KTH)
Wallenberg Wood Science Center (WWSC)
Antal Boldizar
Wallenberg Wood Science Center (WWSC)
Chalmers, Industrial and Materials Science, Engineering Materials
Christian Müller
Chalmers, Chemistry and Chemical Engineering, Applied Chemistry
Wallenberg Wood Science Center (WWSC)
Biomacromolecules
1525-7797 (ISSN) 1526-4602 (eISSN)
Vol. 20 10 3924-3932Subject Categories
Polymer Chemistry
Materials Engineering
Physical Chemistry
Chemical Sciences
DOI
10.1021/acs.biomac.9b00993
PubMed
31525970