Spin-coating: A new approach for improving dispersion of cellulose nanocrystals and mechanical properties of poly (lactic acid) composites

Jamileh Shojaeiarani; Dilpreet S Bajwa; Nicole M Stark

doi:10.1016/j.carbpol.2018.02.069

Spin-coating: A new approach for improving dispersion of cellulose nanocrystals and mechanical properties of poly (lactic acid) composites

Carbohydr Polym. 2018 Jun 15:190:139-147. doi: 10.1016/j.carbpol.2018.02.069. Epub 2018 Feb 23.

Authors

Jamileh Shojaeiarani¹, Dilpreet S Bajwa², Nicole M Stark³

Affiliations

¹ Department of Mechanical Engineering, North Dakota State University, Fargo, ND 58102, United States. Electronic address: jamileh.shojaeiarani@ndsu.edu.
² Department of Mechanical Engineering, North Dakota State University, Fargo, ND 58102, United States. Electronic address: dilpreet.bajwa@ndsu.edu.
³ U.S. Forest Service, Forest Products Laboratory, Madison, WI 53726-2398, United States. Electronic address: nstark@fs.fed.us.

PMID: 29628231
DOI: 10.1016/j.carbpol.2018.02.069

Abstract

This study systematically evaluated the influence of masterbatch preparation techniques, solvent casting and spin-coating methods, on composite properties. Composites were manufactured by combining CNCs masterbatches and PLA resin using twin screw extruder followed by injection molding. Different microscopy techniques were used to investigate the dispersion of CNCs in masterbatches and composites. Thermal, thermomechanical, and mechanical properties of composites were evaluated. Scanning electron microscopy (SEM) images showed superior dispersion of CNCs in spin-coated masterbatches compared to solvent cast masterbatches. At lower CNCs concentrations, both SEM and optical microscope images confirmed more uniform CNCs dispersion in spin-coated composites than solvent cast samples. Degree of crystallinity of PLA exhibited a major enhancement by 147% and 380% in solvent cast and spin-coated composites, respectively. Spin-coated composites with lower CNCs concentration exhibited a noticeable improvement in mechanical properties. However, lower thermal characteristics in spin-coated composites were observed, which could be attributed to the residual solvents in masterbatches.

Keywords: Cellulose nanocrystals; Composites; Masterbatch; Poly(lactic acid); Solvent casting; Spin-coating.