Influence of the addition of microcrystalline cellulose (Mcc) on structural properties of cellulose nanofibrils (NFC) suspensions and films

ABSTRACT

Background:

In the study of biologically-based materials, nanocelluloses have been showing great prominence and positioned themselves as promising alternatives for the production of different industrialized materials. This polymer has received significant attention recently because it is produced from renewable sources and has unique properties offered by its organic nature and semi-crystalline structure. This work aimed to study the structural properties of suspensions and films by increasing MCC concentration in the form of powder with variations of 5 % (m/m) from 5 % to 30 %.

Results:

As expected, incorporating MCC increased the Segal index. The morphological analysis showed an increase in the diameters of the structures (NFC / MCC) in the suspensions when the presence of MCC was more significant, and films with cluster formations were observed. The films showed air permeability. Due to the MCC increase, the surface charge had results close to electrostatically stabilized nanosuspensions. An increase in the resistance to thermal degradation of the films was also observed

Conclusion:

NFC has promising properties for different applications; it provides a film with a stable structure and is resistant to oxygen and tensile stresses. In addition, MCC has excellent potential due to its high crystallinity, structural characteristics, and nature. The increase of the MCC content altered the properties of the suspensions and films produced with NFC, forming a cohesive and resistant film, and influencing the performance of the different properties of the materials evaluated in this study, like air permeability, suspension stability, and thermal resistance.

Keywords:
Microcrystalline Cellulose (MCC); Cellulose nanofibrils (NFC); Cellulose nanomaterials

HIGHLIGHTS

Films made with blends of NFC / MCC can be considered impermeable to the air passage;

MCC increments generated results close to electrostatically stabilized suspensions;

The increase in MCC provided increases in the resistance to thermal degradation of the films;

The increase in the crystallinity index was proportional to the percentages of MCC added.