Surface Modified Cellulose Nanocrystals for Tailoring Interfacial Miscibility and Microphase Separation of Polymer Nanocomposites

Authors: ZHANG, JINLONG - LSU Agcenter; LI, MEI-CHUN - LSU Agcenter; ZHANG, XIUQUIANG - Henan Institute Of Science And Technology; REN, SUXIA - Henan Institute Of Science And Technology; DONG, LILI - Henan Institute Of Science And Technology; LEE, SUNYOUNG - Korea National Agricultural College; Cheng, Huai; LEI, TINGZHOU - Henan Institute Of Science And Technology; WU, QINGLIN - LSU Agcenter

Submitted to: Cellulose
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/14/2019
Publication Date: 5/1/2019
Citation: Zhang, J., Li, M.-C., Zhang, X., Ren, S., Dong, L., Lee, S., Cheng, H.N., Lei, T., Wu, Q. 2019. Surface modified cellulose nanocrystals for tailoring interfacial miscibility and microphase separation of polymer nanocomposites. Cellulose. 26:4301-4312. https://doi.org/10.1007/s10570-019-02379-z.
DOI: https://doi.org/10.1007/s10570-019-02379-z

Interpretive Summary: Nanocellulose represents an excellent opportunity for the use of an agro-based material as a functional filler in polymeric composites. However, for hydrophobic polymers the mechanical properties of the resulting nanocomposites are often mediocre. The problem is due to the poor compatibility between cellulose and the polymeric matrix. In this work, methyl methacrylate was grafted onto the nanocellulose crystals, and the modified material was then used as a filler in an acrylic polymer matrix. The resulting nanocomposite was shown to exhibit significantly improved mechanical properties. This information will allow nanocellulose to be used more effectively with hydrophobic polymers in nanocomposites.

Technical Abstract: High performance nanocomposites with good interfacial miscibility and phase separated morphology have received a lot of attention. In this work, cellulose nanocrystals (CNCs) were first grafted with hydrophobic poly(methyl methacrylate) (PMMA) chains to produce modified CNCs (PMCNCs) with increased thermal stability. Such surface-tailored CNCs effectively influenced the phase morphology and improved the mechanical properties of poly(butyl acrylate-co-methyl methacrylate) (PBA-co-PMMA) nanocomposites. Morphological analysis indicated the presence of microphase separation in PMCNCs/PBA-co-PMMA nanocomposites with PBA as the soft domain and PMMA as well as CNCs as the hard domain. The nanocomposites with 10 wt% PMCNCs/PBA-co-PMMA showed increases in Young’s modulus of more than 20-fold and in tensile strength of about 3-fold when compared to those of the unmodified PBA-co-PMMA copolymer. Therefore, the PMCNCs played a crucial role in controlling the interfacial miscibility and tuning the phase morphology of the nanocomposites. It is also essential to understand the part played by microphase separation in achieving nano-scaled morphological control and in fine-tuning the resultant composite properties.