Improvement in dispersion, thermal and mechanical properties by the incorporating modified cellulose nanocrystal in the Poly (ethylene oxide) matrix

Authors: CHANDA, SAPTAPARNI - Montana State University; BAJWA, DILPREET - Montana State University; Holt, Gregory; BAJWA, SREEKALA - Montana State University

Submitted to: Nanocomposites
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/7/2021
Publication Date: 7/10/2021
Citation: Chanda, S., Bajwa, D., Holt, G.A., Bajwa, S. 2021. Improvement in dispersion, thermal and mechanical properties by the incorporating modified cellulose nanocrystal in the Poly (ethylene oxide) matrix. Nanocomposites. 7(1):87-96. https://doi.org/10.1080/20550324.2021.1942641.
DOI: https://doi.org/10.1080/20550324.2021.1942641

Interpretive Summary: There is a growing concern and effort on the part of researchers to help manufacturers in having more environmentally-friendly options in manufacturing. This research looks at one such option of using cellulose nanocrystals as fillers (very small fibers), as a substitute for the petroleum-based fillers, to improve performance properties of composites. Cellulose is the most abundant bio-based polymer and is commonly associated with wood and cotton. Cotton is the purest natural form of cellulose. Composite test samples were produced using several treatments compared to untreated (conventional) samples. The treatments included both mechanical and chemical methods to disperse the cellulose nanofibers in production of the composite samples. Results indicated a treatment that had the best thermal, physical, and mechanical properties. The results indicated that a successful and eco-friendly path to using cellulose nanofibers exists that can positively improve composite properties.

Technical Abstract: Cellulose nanocrystal reinforced polymeric nanocomposites can be used as potential substitute for the petroleum-based nanocomposites because of their inherent biodegradability, universal accessibility and superior mechanical properties. The most crucial challenge faced in nanocomposite production is effective dispersion of the nanoparticles in the polymer matrix, so the exceptional mechanical properties of the nanoparticles can be transferred to the macroscale properties of the bulk nanocomposites. In this research, a safe, effective and ecofriendly modification was used to functionalize the surface hydroxyl groups of cellulose nanocrystals (CNC) via silane treatment; these modified CNCs were used as reinforcements to prepare poly (ethylene oxide) (PEO)/CNC nanocomposites. The composites were prepared via solvent casting method. The composite properties were evaluated using FT-IR, SEM, TGA, DSC and DMA. The SEM micrographs demonstrated that the composites incorporated with silane treated CNCs showed improvement in the dispersion behavior of the nanoparticles in the matrix. However, with the increase in concentration of silane in the system, the mechanical properties also started degrading, possibly due to the increased self-condensation reaction of the silane linkages onto the CNC surface, which in turn adversely affected the mechanical and physical properties of the resultant composites. Oxidative combustion of the composites containing silane treated CNCs promoted char formation and enhanced thermal stability. The composites containing (1:1) silane treated CNCs exhibited the best crystallization, highest storage modulus and lowest tan d value compared to the other silane containing systems. It can be inferred from this research, that the (1:1) silane treated CNC incorporated composites exhibited the best performance in terms of thermal and physical and mechanical properties. Thus this surface silane treatment of CNC can be a successful and eco-friendly path to disperse CNCs in polymer matrices, enhancing compatibility between matrix and fillers, and reducing polar characteristics of the fillers.