Framställning och utvärdering av nanokompositer innehållande polyamid-12 och nanokristallin cellulosa

Abstract

The global production and consumption of plastic has increased significantly in recent decades, resulting in major environmental challenges related to the use of fossil-based raw materials. One potential approach to reducing this dependence is the incorporation of bio-based materials into existing polymer systems. In this study crystalline nanocellulose (CNC), a bio-based material, was investigated as a reinforcing agent in polymer compo sites. CNC was produced and chemically modified on the surface to improve its compatibility with hydrophobic polymers, since CNC is hydrophilic. Two different azetidinium salts we re used for the modification: 6-6-Az and 8-8-Az. The modified solutions were then dried to enable compounding with polyamide-12 (PA-12) through extrusion. The properties of the resulting composites were evaluated with respect to mechanical properties and thermal stability. The results regarding the mechanical properties generally showed that stiffness and strength increased with increasing CNC weight fraction, while elasticity decreased. Compared with PA-12, all composites displayed improved stiffness and strength, although their elasticity was reduced. The results regarding the thermal stability showed that the modified compo sites, with 2 weight percentage, had a slightly lower degradation temperature than PA-12. Although modified CNC showed improved thermal stability compared to unmodified. To conclude, the results demonstrate that chemically modified CNC can successfully be used as reinforcing agents in PA-12 composites. The modifications resulted in only minor changes in the thermal stability of the material, with both modifications showing similar effects. When comparing the two modifications, no definitive conclusions could be drawn regarding their influence on the overall material properties. However, clear trends were observed with respect to CNC content: increasing CNC weight percentage led to increa sed stiffness and decreased elasticity of the composites. These findings indicate that the material properties can be tailored through adjustment of CNC content, thereby enabling potential application in a range of different fields.