Papers by Wan Mohd Hanif Wan Ya'acob
Cellulose, being an abundantly available
natural biopolymer, has a high potential to replace
synt... more Cellulose, being an abundantly available
natural biopolymer, has a high potential to replace
synthetic fibre. However, a paucity of knowledge and
awareness on the use of cellulose, and agricultural
waste base in particular, hampers efforts to harness
this highly biodegradable resource to its full potential.
This study aimed to extract and characterise cellulose
obtained from pineapple (Ananas comosus) leaves of
cultivar Josapine. Chemical composition analysis
found that the pineapple leaves contain 11.8% lignin
and 55.1% holocellulose, of which 32.6% is alpha
cellulose. This extracted cellulose is light yellow to
pure white in colour. The extraction of cellulose trace
amounts of lignin was found to be between 0.4 and
2.8%. SEM micrograph of pineapple leaves shows
fibrils 36 lm in diameter while the sample cellulose
has defibrillated fibres with an average diameter
ranging from 4.28 to 3.12 lm. Viscosity tests show
the molecular weight (MW) at 3.8671 9 10-4 to
1.0560 9 10-4 and the degree of polymerisation of
447–107, respectively. Characterisation using X-ray
diffraction (XRD), Raman and Fourier-transform
infrared (FTIR) spectroscopy shows the cellulose
samples are cellulose I. As compared to control, XRD
data shows considerably higher percentage of crystallinity
(82.90–85.41%) in all bleached sample with
crystal size ranging from 3.564 to 3.807 nm. In
conclusion, the extraction of cellulose from pineapple
leaves using 2% NaOH and hypochlorite bleaching
retains the original structure of cellulose in the
pineapple leaves. The unique properties of cellulose
microfibre from Josapine pineapple leaf fibres have
great potential for further utilisation in various
industries.
UPNM Press, 2019
The purpose of the study is to determine the optimal condition for mixing factors of natural cell... more The purpose of the study is to determine the optimal condition for mixing factors of natural cellulose or epoxy composite by using response surface method. Three mixing factors selected for the study were degassing agent content, stirring time, and sonication time. As a response, the fracture toughness of the composites was determined by using single edge notch bending test. The level of each factor was selected at 3 conditions which were low, medium, and high. The analysis of variance showed degassing agent content and sonication time were the most significant factors affecting the fracture toughness of the composite. The optimal conditions for mixing factors were 1.34 wt% degassing agent content, 5 minutes for stirring time, and 60 minutes for sonication time. The predicted fracture toughness was 1.6836 MPa.m 0.5 with a desirability value of one. Three validation experiments were conducted to test the generated mathematical model and results showed the percentage difference was in the range of 6% to 15%.
Inderscience, 2017
Nanocellulose from abundant sources is attracting attention because it offers excellent propertie... more Nanocellulose from abundant sources is attracting attention because it offers excellent properties. There are a number of sources that can be used to extract cellulose such as algae, bacteria, non-wood and wood materials. Numerous methods were established in order to isolate nanocellulose and each method produced different types of nanocellulose. However, there are some limitations in merging nanocellulose into polymeric material due to the presence of the hydrophilic group in nanocellulose structure. In order to overcome the limitations, surface modification method was introduced and may improve the homogeneity and interfacial interaction between nanocellulose and polymeric material. Utilising nanocellulose as reinforcement filler has successfully proved the hypothesis, where properties of the composite were enhanced according to several studies.
The objective of this study is to investigate the effect of multi walled carbon nanotube (MWCNT) ... more The objective of this study is to investigate the effect of multi walled carbon nanotube (MWCNT) inclusion on the fracture toughness and the ballistic resistance properties in terms of energy absorption. The determination of fracture toughness of the epoxy/MWCNT matrix was carried out by using a single edge notch bending (SENB) method according to the ASTM D5045-99. Four different weight percentage (wt %) of multi-walled carbon nanotubes (MWCNTs) contents were used, which were 0 wt.%, 0.1 wt.%, 0.55 wt.% and 1.0 wt.%. Epoxy binder and MWCNTs were mixed by using a mechanical stirrer for 10 minutes at 1500 rpm speed and was further sonicated for 30 minutes at 30 Hz amplitude in order to enhance the homogeneity of MWCNTs in the matrix. The composite panel comprised of Twaron fabrics with epoxy resin filled with MWCNTs was fabricated using hand layup and vacuum bagging assist method. The Twaron/epoxy/MWCNT composite panels were subjected to a ballistic test using 9mm Full Metal Jacket bullet at different impacting velocities. From the SENB results, it can be reported that MWCNT inclusion up to 1.0% w.t content shows significant influence towards increment of fracture toughness value. MWCNT also improves the ballistic resistance capability of the composite panel where it was found that the impact energy absorption value was proportionally increase with the epoxy/MWCNT matrix's fracture toughness properties.
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Papers by Wan Mohd Hanif Wan Ya'acob
natural biopolymer, has a high potential to replace
synthetic fibre. However, a paucity of knowledge and
awareness on the use of cellulose, and agricultural
waste base in particular, hampers efforts to harness
this highly biodegradable resource to its full potential.
This study aimed to extract and characterise cellulose
obtained from pineapple (Ananas comosus) leaves of
cultivar Josapine. Chemical composition analysis
found that the pineapple leaves contain 11.8% lignin
and 55.1% holocellulose, of which 32.6% is alpha
cellulose. This extracted cellulose is light yellow to
pure white in colour. The extraction of cellulose trace
amounts of lignin was found to be between 0.4 and
2.8%. SEM micrograph of pineapple leaves shows
fibrils 36 lm in diameter while the sample cellulose
has defibrillated fibres with an average diameter
ranging from 4.28 to 3.12 lm. Viscosity tests show
the molecular weight (MW) at 3.8671 9 10-4 to
1.0560 9 10-4 and the degree of polymerisation of
447–107, respectively. Characterisation using X-ray
diffraction (XRD), Raman and Fourier-transform
infrared (FTIR) spectroscopy shows the cellulose
samples are cellulose I. As compared to control, XRD
data shows considerably higher percentage of crystallinity
(82.90–85.41%) in all bleached sample with
crystal size ranging from 3.564 to 3.807 nm. In
conclusion, the extraction of cellulose from pineapple
leaves using 2% NaOH and hypochlorite bleaching
retains the original structure of cellulose in the
pineapple leaves. The unique properties of cellulose
microfibre from Josapine pineapple leaf fibres have
great potential for further utilisation in various
industries.
natural biopolymer, has a high potential to replace
synthetic fibre. However, a paucity of knowledge and
awareness on the use of cellulose, and agricultural
waste base in particular, hampers efforts to harness
this highly biodegradable resource to its full potential.
This study aimed to extract and characterise cellulose
obtained from pineapple (Ananas comosus) leaves of
cultivar Josapine. Chemical composition analysis
found that the pineapple leaves contain 11.8% lignin
and 55.1% holocellulose, of which 32.6% is alpha
cellulose. This extracted cellulose is light yellow to
pure white in colour. The extraction of cellulose trace
amounts of lignin was found to be between 0.4 and
2.8%. SEM micrograph of pineapple leaves shows
fibrils 36 lm in diameter while the sample cellulose
has defibrillated fibres with an average diameter
ranging from 4.28 to 3.12 lm. Viscosity tests show
the molecular weight (MW) at 3.8671 9 10-4 to
1.0560 9 10-4 and the degree of polymerisation of
447–107, respectively. Characterisation using X-ray
diffraction (XRD), Raman and Fourier-transform
infrared (FTIR) spectroscopy shows the cellulose
samples are cellulose I. As compared to control, XRD
data shows considerably higher percentage of crystallinity
(82.90–85.41%) in all bleached sample with
crystal size ranging from 3.564 to 3.807 nm. In
conclusion, the extraction of cellulose from pineapple
leaves using 2% NaOH and hypochlorite bleaching
retains the original structure of cellulose in the
pineapple leaves. The unique properties of cellulose
microfibre from Josapine pineapple leaf fibres have
great potential for further utilisation in various
industries.