Polyethylene cellulose nanofibrils nanocomposites

Abstract

This paper investigates the use of an aqueous dispersion of polyethylene copolymer with a relatively high content of acrylic acid as a compatibilizer and as an alternative medium to obtain polyethylene CNF nanocomposites. The CNF content was varied from 1 to 90wt% and the appearance, optical, thermal, mechanical and rheological properties, as well the morphology of the films were evaluated. The PE/CNF films are transparent up to 20wt% of NFC indicating a good dispersion of CNF, but a poor distribution, with PE-rich and CNF-rich regions observed by SEM. Improved mechanical properties were achieved, with a 100% and 15,900% increase in the Young's modulus with 1wt% and 90wt% NFC, respectively. The rheological behavior indicated good melt processability. According to these results, aqueous polyolefin dispersions seem to be a promising, easy and relatively fast route for obtaining cellulose/polyolefins nanocomposites with low to high contents of cellulose nanofibrils.

Cellulose nanofibril-reinforced composites using aqueous dispersed ethylene-acrylic acid copolymer

“…This threshold concentration has been reported earlier in similar composites, Larsson et al reported a significant stiffness increase in CNF/PLA composites at a cellulose concentration of 25 wt% (Larsson et al 2012). Moreover, Maia et al reported a doubling of the stiffness to 0.67 GPa in the interval 20-30 wt% for CNF and elastomer composites (Maia et al 2017). The strength r b of the CNF composites was also affected by this concentration threshold (Fig.…”

“…However, addition of cellulose to EAA did not significantly influence the primary crystallinity of EAA (X c2 in Table 2), which varied between 9 and 15% for the composite materials with no apparent trend. Previous works on cellulose composites have shown that cellulose reinforcement in composites can both induce and reduce crystallinity in the matrix phase (Samir et al 2004;Yao et al 2008;Maia et al 2017). The crystallinity of EAA does not significantly change with the addition of cellulose, apart from a small reduction in crystallinity at higher cellulose contents, which suggests that any improvement in mechanical properties of the composites would probably be the result of the cellulose reinforcement and not due to the increased crystallinity of the EAA.…”

“…Water-assisted mixing of CNF and micrometer-sized PLA latex has been used to create fully biodegradable composites with improved tensile properties (Larsson et al 2012). More recently, a aqueous dispersion of an elastomeric co-polymer using poly(ethylene-acrylic acid) as stabilizing surfactant was used to create CNF composite films with improved tensile stiffness (Maia et al 2017).…”

Polymer Nanocomposites with Different Types of Nanofiller

“…Improved mechanical properties were achieved with an increase in the Young's modulus. The rheological behavior indicated good melt processability [113].…”

“…The use of an aqueous dispersion of polyethylene copolymer with a relatively high content of acrylic acid as a compatibilizer and as an alternative medium to obtain polyethylene NFC nanocomposites was a matter of recent study [113]. The NFC content was varied from 1 to 90 wt%, and the appearance, optical, thermal, mechanical and rheological properties, as well the morphology of the films, were evaluated.…”