Partial substitution of pMDI with lignin containing cellulose nanofibrils: low density oriented strand board

ABSTRACT

This study found that the substitution of 6% unbleached cellulose nanofibers (LCNF) into pMDI allowed for a reduction in density of 0.09 and 0.08 g/cm³ for equivalent performance in modulus of elasticity and modulus of rupture respectively; while, all other properties except internal bond were maintained. For panels made above 0.60 g/cm³, it was found that blows would consistently occur due to additional steam pressure from LCNF addition. However, below 0.60 g/cm³ and at 210°C press temperature, all blows at the laboratory scale were eliminated. Industrially, these findings suggests that a company could possibly make a lower density oriented strand board (OSB) of equivalent or better dry mechanical properties while reducing panel weight and avoiding blows. Moving forward, future studies will need to tackle viscosity issues at the sprayer. Our qualitative observation during spraying found that it may be possible to spray up to 3% LCNF without clogging, but at 6% clogging was a mild problem. More research should be performed to improve the homogeneity of spraying at higher substitution rates to assist with industrial commercialization.

KEYWORDS:

• Nanocellulose
• nanofibers
• low density
• OSB
• adhesive
• lignin

Acknowledgements

This work was supported by the Hatch Grant [project number ALA013-1-17004] titled Development of new wood composites for packaging applications, in which, OSB is used for pallet or crate applications. Materials for this work was also supported by a donation from Regions Bank and the corresponding authors time was a reflection of the Regions Bank Professorship which was donated to encourage faculty to develop new products.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Hatch Grant [project number ALA013-1-17004].