Morphological, physical, thermal, and mechanical properties of nanocrystalline cellulose (NCC) were determined. Moisture content as well as oil absorption were also studied. The NCC was obtained from sulfuric acid hydrolysis of wood pulp. Transmission electron microscopy showed that NCC has a diameter of 10 nm and a length of 150 nm. Fourier transform–Raman spectroscopy and x-ray diffraction experiments both showed that NCC has a very high degree of crystallinity. Using an Abbe refractometer, the average refractive index of the NCC in different solvents was determined to be 1.499. Hardness and elastic modulus of the homogeneous, translucent NCC films were determined by nanoindentation technique. Oil absorption and moisture content were related to the particle size.
Ultraviolet light emitting diodes (UV-LEDs) have attracted great interest in recent years. They can be used to polymerize coatings, such as those used for prefinished wood flooring. In this project, two lamps were compared for their suitability to be used on a wood flooring finishing line: a UV-microwave and a UV-LED lamp. Low heat emission was found for the UV-LED lamp compared to the UV-microwave one. This study also reveals that the 4 W/cm2 UV-LED lamp used is not powerful enough to cure UV high solids acrylate coatings while satisfactory results can be obtained for UV water-based formulations. In fact, conversion percentages were found to be low for the high solids coatings, leaving the coatings tacky. Higher conversion percentages were obtained for the UV water-based formulations. As a result, mass loss, hardness, and scratch resistance found for the samples cured by UV-LED were closed to the ones found for the samples cured using the UV microwave lamp.