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Title:	Physico-chemical properties and curing kinetics of bio-based phenolic adhesive from oil palm empty fruit bunch (EFB) fibers
Authors:	Rasidi Roslan (P62858)
Supervisor:	Sarani Zakaria, Prof.Dr
Keywords:	Phenolic resins.
Issue Date:	15-Sep-2014
Description:	Utilization of oil palm empty fruit bunch (EFB) fibers in the production of phenolic (PF) adhesive is an alternative way to reduce the dependency of petroleum-based phenol. In this study, resol-type phenolic adhesive was synthesized from oil palm EFB fibers via two main processes which are liquefaction using phenol and sulfuric acid, followed by resinification reaction at three different weight ratios of formaldehyde to phenol (1.8:1, 2.0:1, and 2.2:1) in alkaline condition. The optimum parameter that gave the highest yield (96%) in the liquefaction process was at weight ratio of phenol to EFB 3:1. Characterization on the liquefied residue shows, peak appearance can be observed in the Fourier Transformation Infrared (FTIR) analysis at 810 and 750 cm-1 which is attributed to the para and meta benzene, respectively or to be specific associated to the p-alkyl phenol and m-alkyl phenol. In the X-ray diffraction (XRD) analysis, crystallinity index (CrI) of the liquefied EFB residue increased from 52% to 61% after liquefaction process. Liquefaction process caused chemical penetration across the grain of the fibers, thus the fibers bundles started to separate into individual fibers as shown in the scanning electron microscope (SEM) micrograph. Meanwhile, characterization of the liquefied phenol formaldehyde (LPF) adhesive shows, increasing the ratio of formaldehyde/liquefied EFB (F/LEFB) has resulted in the increase in the viscosity and molecular weight of the produced PF adhesive. The obtained FTIR spectra confirmed that the chemical functionalities of the produced PF adhesive are almost similar to that of commercial PF adhesive. The nuclear magnetic resonance (NMR) analyses indicated that phenol at para substitution position is preferred over the ortho position for the reactions in both commercial adhesive and adhesive synthesized. In addition, investigation of the curing event of LPF adhesive based on storage modulus development was also recorded by a dynamic mechanical analysis (DMA). Dynamic dual cantilever bending tests at different ramp rates were conducted on two layers wood adherents bonded with an adhesive layer to monitor the curing advancement. Three distinct zones were observed in the storage modulus (E') curve which is thermal softening of wood- adhesive system (40 – 60oC), adhesive curing (110 – 130oC) and thermal softening of cured wood- adhesive system (140 – 180oC). In addition, the higher (LEFB/F) ratio, the faster the vitrification achieved. In comparison, wood joint produced using a commercial PF adhesive cured faster than all LPF wood joints. In order to quantitatively describe both the PF-Com and LPF adhesive in terms of crosslinking processes, Kissinger equation was applied to determine the overall apparent activation energy (Ea). PF-Com sample gives lower Ea value compared to the LPF adhesive (8.31 kJ/mol). However, the Ea of the LPF adhesive increase as the formaldehyde ratio increased. The rigidity as monitored from the DMA storage modulus of the cured adhesive system, was found to linearly correlate with the adhesive shear strength (R2=90%). The shear strength of plywood bonded with produced PF adhesive is surpassing the requirement as specified in JIS K-6852.,Ph.D
Pages:	111
Call Number:	TP1180.P39 R347 2015
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Science and Technology / Fakulti Sains dan Teknologi

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