Tomoko Sugimoto

Cellulose nanocrystals isolated from oil palm trunk

In this study cellulose nanocrystals were isolated from oil palm trunk (Elaeis guineensis) using acid hydrolysis method. The morphology and size of the nanocrystals were characterized using scanning electron microscopy and transmission electron microscopy. The results showed that the nanocrystals isolated from raw oil palm trunk (OPT) fibers and hot water treated OPT fibers had an average diameter of 7.67 nm and 7.97 nm and length of 397.03 nm and 361.70 nm, respectively. Fourier Transform Infrared spectroscopy indicated that lignin and hemicellulose contents decreased. It seems that lignin was completely removed from the samples during chemical treatment. Thermogravimetric analysis demonstrated that cellulose nanocrystals after acid hydrolysis had higher thermal stability compared to the raw and hot water treated OPT fibers. The X-ray diffraction analysis increased crystallinity of the samples due to chemical treatment. The crystalline nature of the isolated nanocrystals from raw and hot water treated OPT ranged from 68 to 70%.

Isolation and characterization of cellulose nanocrystals from parenchyma and vascular bundle of oil palm trunk (Elaeis guineensis).

In this study cellulose nanocrystals were isolated through acid hydrolysis process from parenchyma and vascular bundle of oil palm trunk (Elaeis guineensis). The morphological properties of obtained cellulose nanocrystals were studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The microscopy images showed smoother and cleaner surface of parenchyma cellulose nanocrystals when compared to vascular bundle cellulose nanocrystals. The TEM image shows a higher length and diameter for parenchyma cellulose nanocrystals compared to vascular bundle cellulose nanocrystals. The Fourier transform infrared (FTIR) spectra showed changes in functional groups after acid hydrolysis due to removal of lignin, hemicelluloses and other impurities in both type of cellulose nanocrystals. Crystallinity index of cellulose nanocrystals was observed higher for vascular bundle as compared to parenchyma. Thermogravimetric analysis (TGA) was performed to study the thermal stability of cellulose nanocrystals and it was observed higher for parenchyma cellulose nanocrystals compared to vascular bundle.

Evaluations of some properties of exterior particleboard made from oil palm biomass

This study investigated some physical and mechanical properties of experimental particleboard panels manufactured from different parts of oil palm including bark, leaves, fronds, and trunk consisting of mid-part and core-part using phenol formaldehyde adhesive. Two types of panels with target densities of 0.80 and 1.0 g/cm 3 were manufactured using pressure levels of 5 and 12 MPa, respectively. Both types of panels were pressed at a temperature of 180°C for 20 min. The findings indicated density and pressure level had an influence on the overall properties of the panels. Samples from the core-part had the highest modulus of rupture (MOR) values followed by those panels made from fronds and bark particles. Such samples satisfied MOR characteristics for particleboard type 13 listed in the Japanese Standard. Similarly, panels made from mid-part and leaves also showed satisfactory MOR values for particleboard type 8 based on the same standard. All panels met the IB strength requirement for type 8 except panels made from leaves made at a target density of 1.0 g/cm 3 pressed at 12 MPa. None of the samples satisfied the thickness swelling requirements. The scanning electron microscopy and Fourier transform infrared spectroscopy study indicated positive effect of the resin on interfacial bonding between the particles. Different parts of oil palm may have potential to manufacture exterior particleboard panels with acceptable strength properties. Dimensional properties of the samples need to be enhanced by using different chemicals such as wax or application of various treatments including heat treatment.