Kotchaporn Thangunpai

Kotchaporn Thangunpai

University of Tsukuba, Tsukuba, Japan
orcid

Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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6 June 2024 in Polymers
Verified
Journal Article
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KCKrairop Charoensopa
Krairop Charoensopa
KTKotchaporn Thangunpai
Kotchaporn Thangunpai
Peifu KongPeifu Kong
Peifu Kong
TEToshiharu Enomae
Toshiharu Enomae
WPWat Ploysri
Wat Ploysri
Nanocellulose contains a large number of hydroxyl groups that can be used to modify its surface due to its structure. Owing to its appealing features, such as high strength, great stiffness, and high surface area, nanocellulose is currently gaining popularity in research and industry. The extraction of nanocellulose from the leftover bagasse fiber from sugarcane production by alkaline and acid treatment was successful in this study, with a production yield of 55.6%. The FTIR and XPS results demonstrated a difference in the functional and chemical composition of untreated sugarcane bagasse and extracted nanocellulose. SEM imaging was used to examined the size of the nanocellulose with ImageJ software v1.8.0. TGA, DTG, and XRD analyses were also performed to demonstrate the successful extraction of nanocellulose in terms of its morphology, thermal stability, and crystal structure before and after extraction. The anti-S. aureus activity of the extracted nanocellulose was discovered by using an OD600 test and a colony counting method, and an inhibitory rate of 53.12% was achieved. According to the results, nanocellulose produced from residual sugarcane bagasse could be employed as an antibacterial agent.

30 September 2022 in Polymers
Verified
Journal Article
Open access
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KTKotchaporn Thangunpai
Kotchaporn Thangunpai
DHDonghao Hu
Donghao Hu
XSXianlong Su
Xianlong Su
MKMikio Kajiyama
Mikio Kajiyama
Marcos A. NevesMarcos A. Neves
Marcos A. Neves
TEToshiharu Enomae
Toshiharu Enomae
The plastic waste problem has recently attracted unprecedented attention globally. To reduce the adverse eff ects on environments, biodegradable polymers have been studied to solve the problems. Poly(ε-caprolactone) (PCL) is one of the common biodegradable plastics used on its own or blended with natural polymers because of its excellent properties after blending. However, PCL and natural polymers are difficult to blend due to the polymers’ properties. Grafted polymerization of maleic anhydride and dibenzoyl peroxide (DBPO) with PCL is one of the improvements used for blending immiscible polymers. In this study, we first focused on the effects of three factors (stirring time, maleic anhydride (MA) amount and benzoyl peroxide amount) on the grafting ratio with a maximum value of 4.16% when applying 3.000 g MA and 1.120 g DBPO to 3.375 g PCL with a stirring time of 18 h. After that, the grafting condition was studied based on the kinetic thermal decomposition and activation energy by the Coats–Redfern method. The optimal fitting model was confirmed by the determination coefficient of nearly 1 to explain the contracting volume mechanism of synthesized PCL-g-MA. Consequently, grafted MA hydrophilically augmented PCL as the reduced contact angle of water suggests, facilitating the creation of a plastic–biomaterial composite.

18 August 2023 in Foods
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Journal Article
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Peifu KongPeifu Kong
Peifu Kong
KTKotchaporn Thangunpai
Kotchaporn Thangunpai
AZAinun Zulfikar
Ainun Zulfikar
SMShunsuke Masuo
Shunsuke Masuo
JAJunichi Peter Abe
Junichi Peter Abe
TEToshiharu Enomae
Toshiharu Enomae
This study aimed to prepare anti-Staphylococcus aureus inclusion complexes (ICs) of Hinoki essential oil (HEO) with β-cyclodextrin (β-CD) and 2-hydroxypropyl-β-cyclodextrin (2-HP-β-CD). An ultrasound-assisted kneading method was applied for the complexation for the first time. The recovery yield, embedding fraction and loading capacity of the HEO/β-CD ICs were 92.5%, 78.0% and 11.9%, respectively, while the corresponding values were 80.8%, 73.7% and 12.9% for the HEO/2-HP-β-CD ICs. As well, a comparative study confirmed the efficiency of the ultrasound-assisted kneading method was higher than the traditional kneading method. The results of SEM, XRD, GC-MS and FT-IR suggested the successful formation of ICs. A significant anti-Staphylococcus aureus activity of the fabricated ICs was demonstrated using a colony counting method. Notably, when the dose in liquid culture medium was 20 g L−1, inhibitory rates of 99.8% for HEO/β-CD ICs and 100% for HEO/2-HP-β-CD ICs were achieved. Furthermore, the hydrophilic property of the ICs was proved by water contact angle measurements, implying they have the potential to act as anti-Staphylococcus aureus agents for blending with hydrophilic biodegradable materials for diverse food packaging utilizations.

8 October 2024 in Discover Materials
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Journal Article
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AGAzmi Alvian Gabriel
Azmi Alvian Gabriel
ARAlifia Yuanika Rahmawati
Alifia Yuanika Rahmawati
YTYunita Sasmi Taradipa
Yunita Sasmi Taradipa
TEToshiharu Enomae
Toshiharu Enomae
RFR. M. Muhammad Nur Fauzan
R. M. Muhammad Nur Fauzan
SISurya Iryana Ihsanpuro
Surya Iryana Ihsanpuro
Bioplastics were produced by mixing starch with sorbitol, glacial acetic acid, and carboxymethyl cellulose (CMC) during the manufacturing process. The physical characteristics of the bioplastics were investigated using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Tensile strength, elongation, and Young’s modulus tests were utilized to assess the mechanical characteristics of bioplastics. The bioplastic with the highest tensile strength was BP3 (7.03 ± 0.34 N/mm2), whereas BP0 had a tensile strength of 1.57 ± 0.11 N/m2. The addition of CMC increased the viscosity of the solution and, consequently, the strength of the bioplastic. The range of bioplastic hydrophobicity was ~ 128.32–323.74%. FTIR and XPS test results indicated that the physical mixing utilized during synthesis did not result in the addition of functional groups other than the native functional groups of the substances since no chemical reaction occurred. The thermal behavior investigation revealed that increasing the amount of CMC added to TPS can increase the presence of O–H functional groups in bioplastics, contributing to an increase in the glass transition temperature. Furthermore, both bioplastics broke down at ~ 250 °C.

27 July 2023 in Macromolecular Materials and Engineering
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Journal Article
Open access
KTKotchaporn Thangunpai
Kotchaporn Thangunpai
DHDonghao Hu
Donghao Hu
MKMikio Kajiyama
Mikio Kajiyama
Marcos A. NevesMarcos A. Neves
Marcos A. Neves
TEToshiharu Enomae
Toshiharu Enomae
Plastic waste is a global issue because it causes overflowing landfills and pollution, leading to environmental concerns. To address this crisis, materials that can be decomposed in the natural environment are introduced to replace conventional plastics. Poly‐ɛ‐caprolactone (PCL) is a commonly used plastic that can degrade in natural environments. However, owing to its hydrophobicity, its natural decomposition rate is low. In this study, PCL is modified with maleic anhydride (MA) (PCL‐g‐MA) to increase hydrophilicity and amorphous region for faster decomposition. To assess the hydrolysis in seawater, lipase hydrolysis is performed to compare the decomposition of PCL‐g‐MA and PCL. Consequently, in a Pseudomonas lipase‐containing PBS solution, it takes 72 and 120 h for complete hydrolyze of PCL‐g‐MA and PCL, respectively. MA grafted onto PCL increases the amorphous region, where lipase can easily diffuse into PCL‐g‐MA. Morphological (FESEM and POM images), thermal (TGA and DSC), and structural (FTIR, XRD, and XPS) analyzes support the hydrolysis reaction. The mechanisms proposed in this study confirm that lipase hydrolysis starts in the amorphous regions and then transfers to the crystal regions. This hydrolysis progress is expected to facilitate the creation of eco‐friendly low‐cost PCL‐g‐MA composites with high‐rate hydrolysis, such as bio‐plastics and bio‐fibers.

6 January 2025 in RSC Sustainability
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Journal Article
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RFRm. Muhammad Nur Fauzan
Rm. Muhammad Nur Fauzan
KTKotchaporn Thangunpai
Kotchaporn Thangunpai
ANAkiko Nakagawa-Izumi
Akiko Nakagawa-Izumi
MKMikio Kajiyama
Mikio Kajiyama
TEToshiharu Enomae
Toshiharu Enomae
Recent trends in papermaking have led to an increase in the use of alternative resources. Alginate fibres, derived from marine sourced brown seaweed (blue carbon), offer a potential alternative to wood pulp in paper production. The process of obtaining alginate involves pre-treatment, alkaline extraction, precipitation, and purification. Through successful extraction, alginates were obtained from Laminaria japonica (L. japonica) and Sargassum polycystum (S. polycystum) with yields ranging from 17.4% to 28.9% and 14.7% to 26.8%, respectively. The molecular mass of the alginates ranged from 0.68 × 105 to 2.74 × 105 g mol−1 for L. japonica and from 0.39 × 105 to 0.994 × 105 g mol−1 for S. polycystum. Calcium alginate fibres and wood pulp fibres were combined to create composites. The results from this study suggest that the composites achieved an optimum tensile index when the samples contained 50% calcium alginate fibres. Although the results were promising, the tensile index of the paper made exclusively from pulp fibres remained superior. Furthermore, thermal degradation tests demonstrated improved thermal stability for the composite papers compared to hardwood bleached kraft pulp (HBKP) sheets. In conclusion, a composite prepared from a mixture of calcium alginate and wood pulp fibres was successfully produced and overall 50% inclusion of calcium alginate fibres provided an optimum composite.