Preparation of cellulose nanocrystal-polyoropylene masterbatches by water-assisted thermokinetic mixing

Abstract

In an effort to avoid freeze-drying or solvent blending techniques and to better leverage the fact that preparation of cellulose nanocrystals (CNCs) result in aqueous dispersions, we investigated a water-assisted melt compounding approach to disperse cellulose nanocrystals in polypropylene (PP). A simple, water-based cetyltrimethylammonium bromide (CTAB) treatment of CNCs was used to reduce their hydrophilicity and inhibit hydrogen bonding. The aqueous suspension of treated CNCs was then blended with polypropylene in a thermokinetic mixer with various levels of a maleated polypropylene (MAPP) as a dispersing agent. CNC dispersion was evaluated by optical microscopy, scanning electron microscopy, and rheology. CTAB treatment alone was insufficient to provide good dispersion but dispersion improved greatly with increasing MAPP content. At the highest levels of MAPP, agglomerates were still present but nearly all were well below 1 μm in size. However, despite a CNC content of 8%, little rheological evidence of a network structure was found that would suggest well-dispersed nanocomposites.

Citation

Clemons, Craig; Reiner, Rick. 2020. Preparation of cellulose nanocrystal-polyoropylene masterbatches by water-assisted thermokinetic mixing. ANTEC 2020: The Virtual Edition. 6p.