Glycerol modification of cellulose, can we imitate thermoplasticity?
- Adrian Eliasson
- PhD student,
- KTH
- Co-author(s): Lars Wågberg, Mikael Hedenqvist, Anders Brolin, Eva Malmström
- Supervisor (PhD-students/postdocs): Eva Malmström
- Polymeric materials are essential in today’s modern society and their production has increased exponentially since their commercialization in the 1940s. One of the largest industrial sectors is packaging, estimated to be 146 million tons in 2015.1 A large fraction of the packaging material is single-use and ends up in landfill or is incinerated, as most plastics used are non-degradable and recycling is still challenging in large parts of the world. Material research has focused on decreasing the environmental impact of these kinds of materials by reducing and replacing them with, for example, cellulose-based materials like cardboard, but also more innovative materials like bio-based foams. Cellulose is an abundant biopolymer already widely used and bio-degradable and recyclable. One limiting factor for conventional cellulose-based materials is the limitations when shaping cardboard and paper-based materials. Although cellulose is a polymer it does not show typical polymeric behaviors such as thermo-processability which most synthetic polymers do. Our approach, inspired by the plasticization of gluten, is to incorporate a small amount of plasticizer into the lignocellulose matrix.2 We hypothesize that the small plasticizing molecules will reduce the strong intermolecular interactions within cellulose and enhance molecular mobility. Successful implementation will increase the lignocellulose’s thermo-processability and yield a material that can be processed through conventional thermo-processing such as extrusion or hot-pressing allowing more advanced shaping opportunities than existing methods. During the last three years, we have been working with cellulose to see how it may be modified with the help of glycerol, sorbitol, and starches to achieve a behavior that imitates thermoplasticity. Our work has shown that glycerol that is incorporated into fibers through ultrasonication and then formed into sheets can increase their ductility from 0.5% to 30% without losing significant mechanical integrity.
- TIme of presentation: 13:20
