KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Search Results

Now showing 1 - 10 of 13

Some of the metrics are blocked by your
consent settings
Polyhydroxybutyrate Production from Waste Frying Oil Using Bacillus megaterium: Process Optimization and Economic Analysis and Life Cycle Assessment
(2025-01-01)
Chysirichote, Teerin
;
Tojumsi, Wacharakorn
This study optimized polyhydroxybutyrate (PHB) production from waste frying oil using Bacillus megaterium and evaluated the economic and environmental performance of the process. Free fatty acid (FFA) content, nitrogen concentration, and temperature were examined using a Box–Behnken design. The optimal conditions were 3.18 mM nitrogen, 1.20% FFA, and 35 °C, which produced 58.7% PHB in bacterial dry mass and a maximum yield of 8.9%. The regression models showed high predictive accuracy with errors between 0.6 and 14.7%. Techno-economic analysis showed that chemical use during fermentation and solvent extraction dominated operating costs. For plant capacities of 100 to 400 m3, the minimum selling price ranged from 35.36 to 23.70 USD/kg, depending on selling price and cost variation. Life cycle assessment estimated a carbon footprint of 3.94 kg CO₂-eq/kg PHB, mainly from electricity and solvents. Using renewable electricity and greener or solvent-free extraction could reduce emissions by up to 38%. Overall, waste frying oil is a promising substrate for PHB production, and integrating optimization with economic and life cycle assessment supports the development of sustainable bioplastics.
Some of the metrics are blocked by your
consent settings
Modification of biodegradable thermoplastic cassava starch/kapok fiber incorporated by tartaric acid and processed by compression molding technique
(2024-01-01)
Panjapornpattana, Kanisara
;
Sareethao, Supapich
;
Prachayawarakorn, Jutarat
Thermoplastic starch has been attracted due to its availability, biodegradability, and processability. However, its poor tensile properties, high hydrophilicity and lack of antibacterial activity are still the major concerns for many applications. In current study, several thermoplastic cassava starch samples (THPCS), reinforced with kapok (KP) fibers and modified by varying levels of tartaric acid (TA), a natural organic acid, were prepared to enhance their limitations. All samples were mixed and shaped using an internal mixer and a compression molding machine, respectively. The modified THPCS samples were characterized using analytical techniques such as FTIR, SEM and TGA. Morphology, water uptake, mechanical properties, biodegradability, and antimicrobial performance of various samples were also evaluated. IR peak positions of O–H stretching as well as O–H bending were clearly observed for shifting to lower wavenumbers with the addition of KP fibers or KP fibers/TA, indicating of new H-bond formation. In addition, the use of KP fibers caused the enhancement of mechanical strength and thermal properties including the reduction of water uptake. Moreover, THPCS/KP fiber sample modified by TA presented surface smoothness, good biodegradability, and antibacterial performance against both Staphylococcus aureus and Escherichia coli.
Some of the metrics are blocked by your
consent settings
Vitrimer-like of poly (glycerol sebacate) by using zinc acetate, zinc oxide and Amberlyst as catalysts
(2023-01-01)
Thongkam, Montree
;
Saowsupa, Sairoong
;
Rungrojchaipon, Pesak
Polyglycerol sebacate (PGS) is elastomeric biodegradable polymer with potential biomedical and green packaging applications. This study focuses on the synthesis of vitrimer-like PGS utilizing various catalysts, including Zinc acetate, Zinc oxide and Amberlyst-15. The investigation of vitrimer-like of PGS polymer by polycondensation of glycerol and sebacic acid with various molar ratio of 1:1, 1:1.25 and 1:1.5 will be studied. The synthetic time and temperature were controlled at 72 h, 120 °C, respectively. The prepolymer of PGS had a weight-average molecular weight (Mw.) of 1743. The result of functional group was confirmed by Fourier transforms Infrared spectroscopy (FTIR). The intense C[dbnd]O stretch at 1737 cm−1 confirms the formation of ester bonds. The intense OH stretch at 3454 cm−1 indicated hydroxyl groups from hydrogen bonded. When the quantity of catalyst is increased, the results of hardness are rising but swelling (%) becomes lower. The results showed a polymer network has higher cross-link when the catalyst increases. In addition, the proton nuclear magnetic resonance spectroscopy (1H NMR) analysis found that PGS using catalyst does not have peaks of glycerol.
Some of the metrics are blocked by your
consent settings
Effect of neem wood sawdust content on properties of biodegradable thermoplastic acetylated cassava starch/neem wood sawdust composites
(2017-03-01)
Prachayawarakorn, Jutarat
;
Hanchana, Areeya
Due to several important limitations for applications of thermoplastic starch (TPS), thermoplastic acetylated cassava starch (TPACS) polymer was reinforced by different contents of neem wood sawdust (SD). Thermoplastic cassava starch (TPCS)/SD composites were also prepared and reinforced by different SD contents and compared with the TPACS/SD composites. Morphological, thermal, and biodegradable properties of different composites were also examined. The results showed that IR absorption bands of OH stretching and OH bending vibrations shifted to lower wavenumbers, indicating new hydrogen bond formation for all composites. Stress at maximum load and Young's modulus were significantly improved when the SD content increased for all the TPACS/SD and TPCS/SD composites; strain at maximum load was higher for the TPACS/SD composites. A decrease in water uptake was detected when the SD reinforcement was incorporated into either the TPACS or TPCS matrix.
Some of the metrics are blocked by your
consent settings
Effect of pectin particles and cotton fibers on properties of thermoplastic cassava starch composites
(2016-03-01)
Prachayawarakorn, Jutarat
;
Pattanasin, Worawan
Due to poor mechanical properties and high water uptake of thermoplastic starch (TPS), this research focused on property improvement of thermoplastic cassava starch (TPCS) using natural compatible polymers, i.e. pectin particles and cotton fibers. Different TPCS composites, reinforced by the pectin particles and/or the cotton fibers, were compounded and shaped using an internal mixer and a compression molding machine, respectively. It was found from infrared (IR) spectra that the peak position of O-H stretching of the TPCS polymer clearly shifted to lower wavenumber by the addition of the pectin particles and/or the cotton fibers. Moreover, the significant increase of stress at maximum load and Young’s modulus of the TPCS/pectin particle and the TPCS/cotton fiber composites was observed. The drop of water uptake was also found when the cotton fibers were incorporated into the TPCS matrix with/without pectin particles. In addition, X-Ray Diffraction, Scanning Electron Microscopy and Thermogravimetric Analysis were used to characterize different TPCS composites.
Some of the metrics are blocked by your
consent settings
Effect of pectin contents on properties of biodegradable thermoplastic mung bean starch/low-density polyethylene blends using injection molding technique
(2016-01-01)
Prachayawarakorn, Jutarat
;
Hommanee, Luxana
Mechanical properties and water uptake of thermoplastic starch (TPS)/low-density polyethylene (LDPE) blend are still the main problems for applications of biodegradable polymers; therefore, properties of the TPS/LDPE blends were, then, modified using pectin, a natural gelling agent. In this study, biodegradable polymer blends; prepared from thermoplastic mung bean starch (TPMBS) and LDPE, were processed using an injection molding technique. Different contents of pectin, i.e. 0%, 2%, 4%, 6%, 8% and 10% were added into the TPMBS/ LDPE blend. It was found from Fourier Transform Infrared spectroscopy (FT-IR) spectra that O-H stretching peak shifted to lower wavenumber by the addition of pectin, even with the presence of LDPE. Better phase compatibility between the TPMBS and LDPE phases, observed from Scanning Electron Microscopy (SEM) technique, was also detected by the addition of pectin. In addition, tensile properties of the TPMBS/LDPE blends were also significantly improved by the modification of pectin. Melt flow index, water absorption, thermal degradation temperature and biodegradability of different TPMBS/LDPE blends modified by pectin were also investigated.
Some of the metrics are blocked by your
consent settings
Effect of starch types on properties of biodegradable polymer based on thermoplastic starch process by injection molding technique
(2015-01-01)
Tanetrungroj, Yossathorn
;
Prachayawarakorn, Jutarat
In this study effects of different starch types on the properties of biodegradable polymer based on thermoplastic starch (TPS) were investigated. Different types of starch containing different contents of amylose and amylopectin were used, i.e. cassava starch, mungbean starch, and arrowroot starch. The TPS polymers were compounded and shaped using an internal mixer and an injection molding machine, respectively. It was found that the amount of amylose and amylopectin contents on native starch influence the properties of the TPS polymer. A high amylose starch of TPMS led to higher strength, hardness, degree of crystallization than the high amylopectin starch of TPCS. In addition, function group analysis by Fourier transforms infrared spectrophotometer, water absorption, and biodegradation by soil burial test were also examined.
Some of the metrics are blocked by your
consent settings
Effect of carrageenan on properties of biodegradable thermoplastic cassava starch/low-density polyethylene composites reinforced by cotton fibers
(2014-01-01)
Prachayawarakorn, Jutarat
;
Pomdage, Wanida
Applications of biodegradable thermoplastic starch (TPS) have been restricted due to its poor mechanical properties, limited processability and high water uptake. In order to improve properties and processability, thermoplastic cassava starch (TPCS) was compounded with low-density polyethylene (LDPE). The TPCS/LDPE blend was, then, modified by a natural gelling agent, i.e. carrageenan and natural fibers, i.e. cotton fibers. All composites were compounded and processed using an internal mixer and an injection molding machine, respectively. It was found that stress at maximum load and Young's modulus of the TPCS/LDPE composites significantly increased by the addition of the carrageenan and/or the cotton fibers. The highest mechanical properties were obtained from the TPCS/LDPE composites modified by both the carrageenan and the cotton fibers. Percentage water absorption of all of the TPCS/LDPE composites was found to be similar. All modified composites were also degraded easier than the non-modified one. Furthermore, all the composites were analyzed using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Scanning electron microscopy (SEM). © 2014 Elsevier Ltd.
Some of the metrics are blocked by your
consent settings
Effect of silk protein fibers on properties of thermoplastic rice starch
(2012-05-01)
Prachayawarakorn, J.
;
Hwansanoet, W.
Biodegradable polymer was prepared as thermoplastic starch (TPS). Due to poor mechanical properties and high water absorption of TPS, thermoplastic rice starch (TPRS) was modified by reinforcing with natural silk protein fibers, as an alternative choice of fiber reinforcement. Different contents and lengths of silk fibers were varied and used as the reinforcement. Internal mixer and compression molding machine were used to mix and shaped the TPRS/silk composites. It was found that stress at maximum load and Young's modulus of the TPRS/silk composites significantly increased with the incorporation of silk fibers. Water absorption of the TPRS/silk composites was also dropped by the addition of silk fibers. Moreover, thermal degradation temperatures of the TPRS/silk composites shifted to higher temperatures by the inclusion of the silk fibers. Functional group analysis and X-ray diffraction patterns were analyzed by FI-IR and XRD techniques, respectively. Furthermore, color measurement, morphology and biodegradation by soil burial test were carried out for different TPRS/silk composites. © 2012 The Korean Fiber Society and Springer Netherlands.
Some of the metrics are blocked by your
consent settings
Effect of Agar and Cotton Fiber on Properties of Thermoplastic Waxy Rice Starch Composites
(2012-03-01)
Prachayawarakorn, J.
;
Limsiriwong, N.
;
Kongjindamunee, R.
;
Surakit, S.
Biodegradable polymer from thermoplastic waxy rice starch (TPWRS) was prepared by internal mixer and compression molding. Since tensile properties and water uptake of the TPWRS was still the main disadvantages, the TPWRS sample was, therefore, modified by agar and/or cotton fibers. The effect of different ratios of agar:cotton fibers on properties of the TPWRS matrix were also studied. It was found that new hydrogen bonds could be found for the TPWRS matrix with the addition of different ratios of agar: cotton fibers by the detection of IR peak shift. Tensile properties of the TPWRS sample were significantly improved by the addition of agar or cotton fibers and the highest tensile properties were obtained from the TPWRS composite modified with 4:6 agar:cotton fibers. In addition, thermal degradation temperature and thermal stability of the starch were improved by the incorporation of agar and/or cotton fibers. Moreover, color measurement, morphology, water uptake and biodegradability from soil burial test were also examined. © 2011 Springer Science+Business Media, LLC.

KMITL

Browse

Filters

Settings

Sort By

Results per page

Search Results