Seng Neon - Academia.edu (original) (raw)
Papers by Seng Neon
NIP & Digital Fabrication Conference
ukm.my
... 65 ALKYD RESINS ARE STILL OF MAJOR IMPORTANT BINDERS IN ORGANIC COATINGSAlireza Azimi Nanvaee... more ... 65 ALKYD RESINS ARE STILL OF MAJOR IMPORTANT BINDERS IN ORGANIC COATINGSAlireza Azimi Nanvaee , Rosiyah Yahya , Seng Neon Gan Faculty of Science , Chemistry Department , University of Malaya , 50603 Kuala Lumpur , Malaysia Abstract ...
Annals of Dentistry, Dec 31, 2007
The impact strength of a newly developed experimental polyurethane-based polymer which is derived... more The impact strength of a newly developed experimental polyurethane-based polymer which is derived from palm oil (Experimental PU) was compared with denture polymers; heat-cured and self cured polymethyl methacrylate (PMMA) and Eclipse®, light-activated urethane dimethacrylate prosthetic resin system. Ten specimens were prepared using heatcured PMMA (Meliodent® Heat Cure, Heraeus Kulzer, Germany), self cured PMMA (Meliodent® Rapid Repair, Heraeus Kulzer, Germany), Eclipse® baseplate resin (Dentsply, USA) and Experimental PU material. Specimens were prepared following manufacturer's instructions except for the Experimental PU material where it was prepared in bulk and sectioned to the desired dimension, 64 x 6 x 4 mm. A 'V' notch of approximately 0.8mm in depth was machine cut across the 6mm width. Prior to the Charpy type impact test, specimens were soaked in a water bath for 50 hours at 37ºC. Eclipse® baseplate resin showed the highest impact strength (2.73 kJ/m2±0.54) followed by Meliodent® Rapid Repair (2.50kJ/m2±0.65), Meliodent® Heat Cure (1.96kJ/m2±0.42) and Experimental PU (1.04kJ/m2±0.29). One-way ANOVA showed significant interaction between materials (p<.05) and Tukey HSD revealed that Experimental PU exhibited significantly lower impact strength compared to other materials. Meliodent® Rapid Repair was not significantly different from Meliodent® Heat Cure and Eclipse® baseplate resin. It can be concluded that the Experimental PU exhibited the lowest impact strength while Eclipse® baseplate resin the highest.
Applied Biochemistry and Biotechnology, 2006
Pseudomonas putida was metabolically engineered to produce medium chain length polyhydroxyalkanoa... more Pseudomonas putida was metabolically engineered to produce medium chain length polyhydroxyalkanoate (mcl-PHA) from acetate, a promising carbon source to achieve cost-effective microbial processes. As acetate is known to be harmful to cell growth, P. putida KT2440 was screened from three Pseudomonas strains (P. putida KT2440, P. putida NBRC14164, and P. aeruginosa PH1) as the host with the highest tolerance to 10 g/L of acetate in the medium. Subsequently, P. putida KT2440 was engineered by amplifying the acetate assimilation pathway, including overexpression of the acs (encoding acetyl-CoA synthetase) route and construction of the ackA-pta (encoding acetate kinase-phosphotransacetylase) pathway. The acs overexpressing P. putida KT2440 showed a remarkable increase of mcl-PHA titer (+ 92%), mcl-PHA yield (+ 50%), and cellular mcl-PHA content (+ 43%) compared with the wild-type P. putida KT2440, which indicated that acetate could be a potential substrate for biochemical production of mcl-PHA by engineered P. putida.
NIP & Digital Fabrication Conference
A series of poly(urea-formaldehyde) (PUF) microcapsules filled with dicyclopentadiene (DCPD) was ... more A series of poly(urea-formaldehyde) (PUF) microcapsules filled with dicyclopentadiene (DCPD) was successfully prepared by in situ polymerization. The effect of diverse process parameters and ingredients on the morphology of the microcapsules was observed by SEM, optical microscopy (OM) and digital microscopy. Different techniques for the characterization of the chemical structure and the core content were considered such as FT-IR and (1)H-NMR as well as the characterization of thermal properties by DSC. High yields of free flowing powder of spherical microcapsules were produced. The synthesized microcapsules can be incorporated into another polymeric host material. In the event the host material cracks due to excessive stress or strong impact, the microcapsules would rupture to release the DCPD, which could polymerize to repair the crack. This record was migrated from the OpenDepot repository service in June, 2017 before shutting down.
![Research paper thumbnail of Improved processability of electrospun poly[(R)-3-hydroxybutyric acid] through blending with medium-chain length poly(3-hydroxyalkanoates) produced byPseudomonas putidafrom oleic acid](https://attachments.academia-assets.com/108672226/thumbnails/1.jpg)
](Materials Research Innovations, 2014
Polyhydroxyalkanoates are bacterial biopolyesters having good biocompatibility and biodegradabili... more Polyhydroxyalkanoates are bacterial biopolyesters having good biocompatibility and biodegradability. Poly[(R)-3-hydroxybutyric acid] is the least expensive/costly and most easily available member of this family. However, poly[(R)-3-hydroxybutyric acid] is very brittle because of its high crystallinity. Its poor processability poses limitations on its application. Blending of this material with another amorphous flexible polymer has been a common practice. In this research, we have improved the properties of poly[(R)-3-hydroxybutyric acid] through blending with a palm oil-based medium-chain length polyhydroxyalkanoate. Solution blending was carried out at four different ratios to produce electrospun fibres. As expected, the addition of medium-chain length polyhydroxyalkanoate has reduced the brittleness of poly[(R)-3-hydroxybutyric acid], through reducing the crystallinity. In addition, it has enabled the reduction of the diameter of the electrospun fibres and shifted it from micrometre towards nanometres, which can improve its porosity and permeability to make it a potential material in biomedical applications.
AIP Conference Proceedings, 2009
A planar coil RF inductively coupled plasma (PC-RFICP) systems is set up for the purpose of thin ... more A planar coil RF inductively coupled plasma (PC-RFICP) systems is set up for the purpose of thin film deposition. The system is powered by a 13.56 MHz, 550 W, 50 Omega RF generator. The RF power is transferred to the plasma via a planar induction coil. The impedance matching unit consists of an air core step-down transformer and a tunable
Materials Research Innovations, 2014
ABSTRACT
International Journal of Polymeric Materials and Polymeric Biomaterials, 2015
Journal of the Japan Society of Colour Material, 2011
The oleic acid polyester macromer was synthesized from 40 parts of oleic acid, 34 parts of phthal... more The oleic acid polyester macromer was synthesized from 40 parts of oleic acid, 34 parts of phthalic anhydride and 26 parts of glycerol. It might be copolymerized with MMA in toluene solution using a free radical initiator. The ratio between the macromer and MMA monomer was varied and the effect on the copolymers properties such as the glass transition temperature, molecular weight, thermal stability and film properties were studied. H-NMR spectroscopy was used to provide evidence of the reaction between the macromer and MMA during the copolymerization. Increasing the amount of macromer led to a decrease in the polymerization rate. On the other hand, increasing the amount of MMA leads to increasing molecular weight and higher Tg value. The coating obtained with the highest ratio of MMA exhibited the best overall physico-chemical properties. Results further reveal that the alkali and water resistance improved significantly with the increase in MMA content in the copolymer.
Biosensors and Bioelectronics, 2015
Electrospun polyhydroxybutyrate (PHB) fibers were dip-coated by polymethyl methacrylate-co-methac... more Electrospun polyhydroxybutyrate (PHB) fibers were dip-coated by polymethyl methacrylate-co-methacrylic acid, poly(MMA-co-MAA), which was synthesized in different molar ratios of the monomers via free-radical polymerization. Fabricated platfrom was employed for immobilization of the dengue antibody and subsequent detection of dengue enveloped virus in enzyme-linked immunosorbent assay (ELISA). There is a major advantage for combination of electrospun fibers and copolymers. Fiber structre of electrospun PHB provides large specific surface area available for biomolecular interaction. In addition, polymer coated parts of the platform inherited the premanent presence of surface carboxyl (-COOH) groups from MAA segments of the copolymer which can be effectively used for covalent and physical protein immobilization. By tuning the concentration of MAA monomers in polymerization reaction the concentration of surface-COOH groups can be carefully controlled. Therefore two different techniques have been used for immobilization of the dengue antibody aimed for dengue detection: physical attachment of dengue antibodies to the surface and covalent immobilization of antibodies through carbodiimide chemistry. In that perspective, several different characterization techniques were employed to investigate the new polymeric fiber platform such as scanning electron microscopy (SEM), atomic force microscopy (AFM), water contact angle (WCA) measurement and UV-vis titration. Regardless of the immobilization techniques, substantially higher signal intensity was recorded from developed platform in comparison to the conventional ELISA assay.
... Page 2. 1 Coating performances of copolymers from a novel palm oil-based macromer and methyl ... more ... Page 2. 1 Coating performances of copolymers from a novel palm oil-based macromer and methyl methacrylate S. Ataei, R. Yahya and SN Gan1 ... dissolving in a solvent, although this cannot eliminate the effects of polarity and hydrogen bonding (Ayman et al., 2007). ...
Advanced Materials Research, 2013
With blooming interests in the research of biodegradable polyesters produced from microorganisms ... more With blooming interests in the research of biodegradable polyesters produced from microorganisms as well as polymer processing and technology, this study is intended to reveal the influence of thermal treatment on the molecular weight of poly (3-hydroxybutyrate-co-3 mol% 3-hydroxyhexanoate)/P(3HB-co-3 mol% 3HHx), a copolymer of polyhydroxyalkanoates (PHA). P(3HB-co-3 mol% 3HHx) was thermally treated using Differential Scanning Calorimeter and analyzed using Gel Permeation Chromatography and Attenuated Total Reflectance-Fourier transform infrared (ATR-FTIR) spectrometer. Results from gel permeation chromatography suggest a major reduction of molecular weight up to 50 % when P(3HB-co-3 mol% 3HHx) is exposed to 180 °C for 30 mins. The half-time degradation of P(3HB-co-3 mol% 3HHx) treated at 170 °C and 180 °C is 14.1 and 9.9 mins, respectively. FTIR spectroscopy shows an increase absorbance intensity of P(3HB-co-3 mol% 3HHx) after thermal treatment, indicating a formation of more alken...
International Journal of Materials Engineering Innovation, 2013
Blending of polymers has been a popular technique for making new materials with improved properti... more Blending of polymers has been a popular technique for making new materials with improved properties or processability. The synergistic properties in the blends are related to the miscibility of the components when there are significant interactions between the constituents. This paper reports the preparation of reactive blends of poly(ethylene oxide) (PEO) and acetic acid-modified epoxidised natural rubber (ENR50, which contains 50% of the isoprene units converted to epoxide groups) by solution casting. The carboxylic acid modification of ENR50 was carried out by reacting the ENR50 dissolved in toluene with excess acetic acid at 100°C. Ring-opening of epoxide group by acetic acid has led to an increase in the T g. The effects of blend ratio of the acetic acid-modified ENR50 and PEO on the thermal properties were studied. The initial ENR50 has a T g of −29°C and the acetic acid-modified ENR50 has led to a new T g of 10°C. FTIR results showed that there was no chemical reaction between the acetic acid-modified ENR50 and PEO in the blends. This is in agreement with the DSC results where two distinct T g s were observed in the blends.
Sensors and Actuators A: Physical, 2014
In this study, an optical microfiber sensor coated with conducting polymer, polyaniline (PAni) is... more In this study, an optical microfiber sensor coated with conducting polymer, polyaniline (PAni) is investigated as a detector for alcohols. PAni was synthesized by chemical oxidation method and dioctyl sodium sulfosuccinate (AOT) was used as the dopant. PAni was then coated onto the microfiber by drop coating method. The proposed sensor exhibits wavelength shift in the output spectrum in response to various types of alcohols at different concentrations. The output response can be associated with the solution refractive index and number of alkyl substituent of alcohol. Furthermore, this sensor also shows excellent repeatability in the detection. In conclusion, a conducting polymer based microfiber optical sensor for alcohol detection with simple, low cost and effective setup was successfully achieved in this study.
Progress in Organic Coatings, 2013
The present study describes the modification of long oil palm stearin based alkyd resin through b... more The present study describes the modification of long oil palm stearin based alkyd resin through blending it with a commercially available ketone resin to improve its coating characteristics. The effects of blending on air drying time, hardness, adhesion, gloss, impact strength, chemical resistance and thermal behavior of dried films of blends were investigated and compared to virgin alkyds. It was found that blending results in modifying coating characteristics of palm stearin based alkyd resins, significantly. Best result was observed for weight ratio 70:30 of alkyd and ketone resins.
Polymer Degradation and Stability, 2010
Medium-chain-length poly(3-hydoxyalkanoates) (mcl-PHA), comprising six to fourteen carbon-chainle... more Medium-chain-length poly(3-hydoxyalkanoates) (mcl-PHA), comprising six to fourteen carbon-chainlength monomers, are natural thermoplastic polyesters synthesized by fluorescent pseudomonades. In this study, mcl-PHA was produced by Pseudomonas putida from oleic acid in aerobic shake flask fermentation. Thermal degradation of mcl-PHA was performed at temperatures in the range of 160e180 C. Thermodynamic parameters of mcl-PHA thermal degradation were determined where degradation activation energy, E d and pre-exponential factor, A equal to 85.3 kJ mol À1 and 6.07 Â 10 5 s À1 , respectively; and exhibited a negative activation entropy (ΔS) of À139.4 J K À1 mol À1. Titration was carried out to determine the carboxylic terminal concentration and used to correlate number-average molecular weight (M n) of the polymers. Thermally-degraded PHA contained higher amount of carboxylic terminals and lower M n compared to the initial PHA and these results coincide with the decreased M n in GPC analysis. Thermal properties of initial and degraded mcl-PHA were characterized by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The thermal decomposition mechanism was investigated following the analyses of the degradation products using 400-MHz 1 H NMR, FTIR spectroscopy and GC analysis. The overall decomposition reaction is the hydrolysis of ester linkages to produce hydroxyl and carboxylic terminals. A small proportion of unsaturated side chain fragments would undergo oxidative cleavage at C]C linkages, producing minor amount of low-molecular weight esters and acids. At higher temperatures, the hydroxyl terminal can undergo dehydration to form an alkenyl terminal.
Polymer Composites, 2013
In this study, novel Polyaniline (PAni)/TiO2 nanocomposites were applied on fluoride‐doped tin ox... more In this study, novel Polyaniline (PAni)/TiO2 nanocomposites were applied on fluoride‐doped tin oxide (FTO) glass to act as an efficient counter electrode in dye‐sensitized solar cell (DSSC) application. PAni/TiO2 nanocomposites were synthesized via chemical oxidation process using di‐2‐ethylhexylsulfosuccinate sodium salt (NaDEHS) as dopant. The nanocomposites were characterized using fourier transform infrared and ultraviolet‐visible spectrometers. In the application of PAni as the counter electrode in the solar cell, the film showed poor adhesion on the FTO glass. Palm oil‐based alkyd was introduced into the nanocomposite mixture to improve the adhesion of the film. The findings in the work show that strong adhesion of PAni on FTO glasses has led to higher incident photon to current conversion efficiency (IPCE) in solar cell. The short circuit current (Jsc), Voc (open circuit voltage), and IPCE of the resulted PAni/TiO2 counter electrode with good adhesion in DSSC are 15.8 mA/cm2,...
NIP & Digital Fabrication Conference
ukm.my
... 65 ALKYD RESINS ARE STILL OF MAJOR IMPORTANT BINDERS IN ORGANIC COATINGSAlireza Azimi Nanvaee... more ... 65 ALKYD RESINS ARE STILL OF MAJOR IMPORTANT BINDERS IN ORGANIC COATINGSAlireza Azimi Nanvaee , Rosiyah Yahya , Seng Neon Gan Faculty of Science , Chemistry Department , University of Malaya , 50603 Kuala Lumpur , Malaysia Abstract ...
Annals of Dentistry, Dec 31, 2007
The impact strength of a newly developed experimental polyurethane-based polymer which is derived... more The impact strength of a newly developed experimental polyurethane-based polymer which is derived from palm oil (Experimental PU) was compared with denture polymers; heat-cured and self cured polymethyl methacrylate (PMMA) and Eclipse®, light-activated urethane dimethacrylate prosthetic resin system. Ten specimens were prepared using heatcured PMMA (Meliodent® Heat Cure, Heraeus Kulzer, Germany), self cured PMMA (Meliodent® Rapid Repair, Heraeus Kulzer, Germany), Eclipse® baseplate resin (Dentsply, USA) and Experimental PU material. Specimens were prepared following manufacturer's instructions except for the Experimental PU material where it was prepared in bulk and sectioned to the desired dimension, 64 x 6 x 4 mm. A 'V' notch of approximately 0.8mm in depth was machine cut across the 6mm width. Prior to the Charpy type impact test, specimens were soaked in a water bath for 50 hours at 37ºC. Eclipse® baseplate resin showed the highest impact strength (2.73 kJ/m2±0.54) followed by Meliodent® Rapid Repair (2.50kJ/m2±0.65), Meliodent® Heat Cure (1.96kJ/m2±0.42) and Experimental PU (1.04kJ/m2±0.29). One-way ANOVA showed significant interaction between materials (p<.05) and Tukey HSD revealed that Experimental PU exhibited significantly lower impact strength compared to other materials. Meliodent® Rapid Repair was not significantly different from Meliodent® Heat Cure and Eclipse® baseplate resin. It can be concluded that the Experimental PU exhibited the lowest impact strength while Eclipse® baseplate resin the highest.
Applied Biochemistry and Biotechnology, 2006
Pseudomonas putida was metabolically engineered to produce medium chain length polyhydroxyalkanoa... more Pseudomonas putida was metabolically engineered to produce medium chain length polyhydroxyalkanoate (mcl-PHA) from acetate, a promising carbon source to achieve cost-effective microbial processes. As acetate is known to be harmful to cell growth, P. putida KT2440 was screened from three Pseudomonas strains (P. putida KT2440, P. putida NBRC14164, and P. aeruginosa PH1) as the host with the highest tolerance to 10 g/L of acetate in the medium. Subsequently, P. putida KT2440 was engineered by amplifying the acetate assimilation pathway, including overexpression of the acs (encoding acetyl-CoA synthetase) route and construction of the ackA-pta (encoding acetate kinase-phosphotransacetylase) pathway. The acs overexpressing P. putida KT2440 showed a remarkable increase of mcl-PHA titer (+ 92%), mcl-PHA yield (+ 50%), and cellular mcl-PHA content (+ 43%) compared with the wild-type P. putida KT2440, which indicated that acetate could be a potential substrate for biochemical production of mcl-PHA by engineered P. putida.
NIP & Digital Fabrication Conference
A series of poly(urea-formaldehyde) (PUF) microcapsules filled with dicyclopentadiene (DCPD) was ... more A series of poly(urea-formaldehyde) (PUF) microcapsules filled with dicyclopentadiene (DCPD) was successfully prepared by in situ polymerization. The effect of diverse process parameters and ingredients on the morphology of the microcapsules was observed by SEM, optical microscopy (OM) and digital microscopy. Different techniques for the characterization of the chemical structure and the core content were considered such as FT-IR and (1)H-NMR as well as the characterization of thermal properties by DSC. High yields of free flowing powder of spherical microcapsules were produced. The synthesized microcapsules can be incorporated into another polymeric host material. In the event the host material cracks due to excessive stress or strong impact, the microcapsules would rupture to release the DCPD, which could polymerize to repair the crack. This record was migrated from the OpenDepot repository service in June, 2017 before shutting down.
Materials Research Innovations, 2014
Polyhydroxyalkanoates are bacterial biopolyesters having good biocompatibility and biodegradabili... more Polyhydroxyalkanoates are bacterial biopolyesters having good biocompatibility and biodegradability. Poly[(R)-3-hydroxybutyric acid] is the least expensive/costly and most easily available member of this family. However, poly[(R)-3-hydroxybutyric acid] is very brittle because of its high crystallinity. Its poor processability poses limitations on its application. Blending of this material with another amorphous flexible polymer has been a common practice. In this research, we have improved the properties of poly[(R)-3-hydroxybutyric acid] through blending with a palm oil-based medium-chain length polyhydroxyalkanoate. Solution blending was carried out at four different ratios to produce electrospun fibres. As expected, the addition of medium-chain length polyhydroxyalkanoate has reduced the brittleness of poly[(R)-3-hydroxybutyric acid], through reducing the crystallinity. In addition, it has enabled the reduction of the diameter of the electrospun fibres and shifted it from micrometre towards nanometres, which can improve its porosity and permeability to make it a potential material in biomedical applications.
AIP Conference Proceedings, 2009
A planar coil RF inductively coupled plasma (PC-RFICP) systems is set up for the purpose of thin ... more A planar coil RF inductively coupled plasma (PC-RFICP) systems is set up for the purpose of thin film deposition. The system is powered by a 13.56 MHz, 550 W, 50 Omega RF generator. The RF power is transferred to the plasma via a planar induction coil. The impedance matching unit consists of an air core step-down transformer and a tunable
Materials Research Innovations, 2014
ABSTRACT
International Journal of Polymeric Materials and Polymeric Biomaterials, 2015
Journal of the Japan Society of Colour Material, 2011
The oleic acid polyester macromer was synthesized from 40 parts of oleic acid, 34 parts of phthal... more The oleic acid polyester macromer was synthesized from 40 parts of oleic acid, 34 parts of phthalic anhydride and 26 parts of glycerol. It might be copolymerized with MMA in toluene solution using a free radical initiator. The ratio between the macromer and MMA monomer was varied and the effect on the copolymers properties such as the glass transition temperature, molecular weight, thermal stability and film properties were studied. H-NMR spectroscopy was used to provide evidence of the reaction between the macromer and MMA during the copolymerization. Increasing the amount of macromer led to a decrease in the polymerization rate. On the other hand, increasing the amount of MMA leads to increasing molecular weight and higher Tg value. The coating obtained with the highest ratio of MMA exhibited the best overall physico-chemical properties. Results further reveal that the alkali and water resistance improved significantly with the increase in MMA content in the copolymer.
Biosensors and Bioelectronics, 2015
Electrospun polyhydroxybutyrate (PHB) fibers were dip-coated by polymethyl methacrylate-co-methac... more Electrospun polyhydroxybutyrate (PHB) fibers were dip-coated by polymethyl methacrylate-co-methacrylic acid, poly(MMA-co-MAA), which was synthesized in different molar ratios of the monomers via free-radical polymerization. Fabricated platfrom was employed for immobilization of the dengue antibody and subsequent detection of dengue enveloped virus in enzyme-linked immunosorbent assay (ELISA). There is a major advantage for combination of electrospun fibers and copolymers. Fiber structre of electrospun PHB provides large specific surface area available for biomolecular interaction. In addition, polymer coated parts of the platform inherited the premanent presence of surface carboxyl (-COOH) groups from MAA segments of the copolymer which can be effectively used for covalent and physical protein immobilization. By tuning the concentration of MAA monomers in polymerization reaction the concentration of surface-COOH groups can be carefully controlled. Therefore two different techniques have been used for immobilization of the dengue antibody aimed for dengue detection: physical attachment of dengue antibodies to the surface and covalent immobilization of antibodies through carbodiimide chemistry. In that perspective, several different characterization techniques were employed to investigate the new polymeric fiber platform such as scanning electron microscopy (SEM), atomic force microscopy (AFM), water contact angle (WCA) measurement and UV-vis titration. Regardless of the immobilization techniques, substantially higher signal intensity was recorded from developed platform in comparison to the conventional ELISA assay.
... Page 2. 1 Coating performances of copolymers from a novel palm oil-based macromer and methyl ... more ... Page 2. 1 Coating performances of copolymers from a novel palm oil-based macromer and methyl methacrylate S. Ataei, R. Yahya and SN Gan1 ... dissolving in a solvent, although this cannot eliminate the effects of polarity and hydrogen bonding (Ayman et al., 2007). ...
Advanced Materials Research, 2013
With blooming interests in the research of biodegradable polyesters produced from microorganisms ... more With blooming interests in the research of biodegradable polyesters produced from microorganisms as well as polymer processing and technology, this study is intended to reveal the influence of thermal treatment on the molecular weight of poly (3-hydroxybutyrate-co-3 mol% 3-hydroxyhexanoate)/P(3HB-co-3 mol% 3HHx), a copolymer of polyhydroxyalkanoates (PHA). P(3HB-co-3 mol% 3HHx) was thermally treated using Differential Scanning Calorimeter and analyzed using Gel Permeation Chromatography and Attenuated Total Reflectance-Fourier transform infrared (ATR-FTIR) spectrometer. Results from gel permeation chromatography suggest a major reduction of molecular weight up to 50 % when P(3HB-co-3 mol% 3HHx) is exposed to 180 °C for 30 mins. The half-time degradation of P(3HB-co-3 mol% 3HHx) treated at 170 °C and 180 °C is 14.1 and 9.9 mins, respectively. FTIR spectroscopy shows an increase absorbance intensity of P(3HB-co-3 mol% 3HHx) after thermal treatment, indicating a formation of more alken...
International Journal of Materials Engineering Innovation, 2013
Blending of polymers has been a popular technique for making new materials with improved properti... more Blending of polymers has been a popular technique for making new materials with improved properties or processability. The synergistic properties in the blends are related to the miscibility of the components when there are significant interactions between the constituents. This paper reports the preparation of reactive blends of poly(ethylene oxide) (PEO) and acetic acid-modified epoxidised natural rubber (ENR50, which contains 50% of the isoprene units converted to epoxide groups) by solution casting. The carboxylic acid modification of ENR50 was carried out by reacting the ENR50 dissolved in toluene with excess acetic acid at 100°C. Ring-opening of epoxide group by acetic acid has led to an increase in the T g. The effects of blend ratio of the acetic acid-modified ENR50 and PEO on the thermal properties were studied. The initial ENR50 has a T g of −29°C and the acetic acid-modified ENR50 has led to a new T g of 10°C. FTIR results showed that there was no chemical reaction between the acetic acid-modified ENR50 and PEO in the blends. This is in agreement with the DSC results where two distinct T g s were observed in the blends.
Sensors and Actuators A: Physical, 2014
In this study, an optical microfiber sensor coated with conducting polymer, polyaniline (PAni) is... more In this study, an optical microfiber sensor coated with conducting polymer, polyaniline (PAni) is investigated as a detector for alcohols. PAni was synthesized by chemical oxidation method and dioctyl sodium sulfosuccinate (AOT) was used as the dopant. PAni was then coated onto the microfiber by drop coating method. The proposed sensor exhibits wavelength shift in the output spectrum in response to various types of alcohols at different concentrations. The output response can be associated with the solution refractive index and number of alkyl substituent of alcohol. Furthermore, this sensor also shows excellent repeatability in the detection. In conclusion, a conducting polymer based microfiber optical sensor for alcohol detection with simple, low cost and effective setup was successfully achieved in this study.
Progress in Organic Coatings, 2013
The present study describes the modification of long oil palm stearin based alkyd resin through b... more The present study describes the modification of long oil palm stearin based alkyd resin through blending it with a commercially available ketone resin to improve its coating characteristics. The effects of blending on air drying time, hardness, adhesion, gloss, impact strength, chemical resistance and thermal behavior of dried films of blends were investigated and compared to virgin alkyds. It was found that blending results in modifying coating characteristics of palm stearin based alkyd resins, significantly. Best result was observed for weight ratio 70:30 of alkyd and ketone resins.
Polymer Degradation and Stability, 2010
Medium-chain-length poly(3-hydoxyalkanoates) (mcl-PHA), comprising six to fourteen carbon-chainle... more Medium-chain-length poly(3-hydoxyalkanoates) (mcl-PHA), comprising six to fourteen carbon-chainlength monomers, are natural thermoplastic polyesters synthesized by fluorescent pseudomonades. In this study, mcl-PHA was produced by Pseudomonas putida from oleic acid in aerobic shake flask fermentation. Thermal degradation of mcl-PHA was performed at temperatures in the range of 160e180 C. Thermodynamic parameters of mcl-PHA thermal degradation were determined where degradation activation energy, E d and pre-exponential factor, A equal to 85.3 kJ mol À1 and 6.07 Â 10 5 s À1 , respectively; and exhibited a negative activation entropy (ΔS) of À139.4 J K À1 mol À1. Titration was carried out to determine the carboxylic terminal concentration and used to correlate number-average molecular weight (M n) of the polymers. Thermally-degraded PHA contained higher amount of carboxylic terminals and lower M n compared to the initial PHA and these results coincide with the decreased M n in GPC analysis. Thermal properties of initial and degraded mcl-PHA were characterized by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The thermal decomposition mechanism was investigated following the analyses of the degradation products using 400-MHz 1 H NMR, FTIR spectroscopy and GC analysis. The overall decomposition reaction is the hydrolysis of ester linkages to produce hydroxyl and carboxylic terminals. A small proportion of unsaturated side chain fragments would undergo oxidative cleavage at C]C linkages, producing minor amount of low-molecular weight esters and acids. At higher temperatures, the hydroxyl terminal can undergo dehydration to form an alkenyl terminal.
Polymer Composites, 2013
In this study, novel Polyaniline (PAni)/TiO2 nanocomposites were applied on fluoride‐doped tin ox... more In this study, novel Polyaniline (PAni)/TiO2 nanocomposites were applied on fluoride‐doped tin oxide (FTO) glass to act as an efficient counter electrode in dye‐sensitized solar cell (DSSC) application. PAni/TiO2 nanocomposites were synthesized via chemical oxidation process using di‐2‐ethylhexylsulfosuccinate sodium salt (NaDEHS) as dopant. The nanocomposites were characterized using fourier transform infrared and ultraviolet‐visible spectrometers. In the application of PAni as the counter electrode in the solar cell, the film showed poor adhesion on the FTO glass. Palm oil‐based alkyd was introduced into the nanocomposite mixture to improve the adhesion of the film. The findings in the work show that strong adhesion of PAni on FTO glasses has led to higher incident photon to current conversion efficiency (IPCE) in solar cell. The short circuit current (Jsc), Voc (open circuit voltage), and IPCE of the resulted PAni/TiO2 counter electrode with good adhesion in DSSC are 15.8 mA/cm2,...