【公開日：2025.06.10】【最終更新日：2025.05.19】
課題データ / Project Data
課題番号 / Project Issue Number
24YG0084
利用課題名 / Title
Starch-Based Bioplastic Composites Reinforced with Citric Acid-Cured Epoxidized Soybean Oil Oligomer
利用した実施機関 / Support Institute
山形大学 / Yamagata Univ.
機関外・機関内の利用 / External or Internal Use
内部利用（ARIM事業参画者以外）/Internal Use (by non ARIM members)
技術領域 / Technology Area
【横断技術領域 / Cross-Technology Area】（主 / Main）計測・分析/Advanced Characterization（副 / Sub）加工・デバイスプロセス/Nanofabrication
【重要技術領域 / Important Technology Area】（主 / Main）次世代バイオマテリアル/Next-generation biomaterials（副 / Sub）マルチマテリアル化技術・次世代高分子マテリアル/Multi-material technologies / Next-generation high-molecular materials
キーワード / Keywords
デンプン/澱粉,エポキシ化大豆油,クエン酸,生分解性材料/ Biodegradable material,X線回折/ X-ray diffraction,成形/ Molding,高強度・生分解性プラスチック/ High-strength, biodegradable plastic
利用者と利用形態 / User and Support Type
利用者名（課題申請者）/ User Name (Project Applicant)
Pansuwan Thanaboon
所属名 / Affiliation
山形大学大学院有機材料システム研究科
共同利用者氏名 / Names of Collaborators in Other Institutes Than Hub and Spoke Institutes
ARIM実施機関支援担当者 / Names of Collaborators in The Hub and Spoke Institutes
利用形態 / Support Type
（主 / Main）機器利用/Equipment Utilization（副 / Sub）-
利用した主な設備 / Equipment Used in This Project
報告書データ / Report
概要（目的・用途・実施内容）/ Abstract (Aim, Use Applications and Contents)
Growing environmental awareness has led to an increased interest in using materials derived from natural resources. Thermoplastic starch is one such material. However, it suffers from poor mechanical properties. This study aims to enhance these properties by developing a composite material using a bio-based epoxy oligomer derived from epoxidized soybean oil (ESO) and citric acid (CA). The objective is to investigate the potential of this natural-based epoxy oligomer to improve the mechanical strength and compatibility of thermoplastic starch.
実験 / Experimental
Preparation
of bio-based epoxy citric acid-cured epoxidized soybean oil oligomer (EPO).
The stoichiometric ratio between epoxides
and carboxylic acid groups was utilized. Initially, 2.70 g of citric acid was
dissolved in 0.37 ml of distilled water and thereafter heated up to a
temperature of 90°C. 10 g of ESO was also preheated to a temperature of 90°C.
Afterward, the CA solution was mixed with the preheated ESO under vigorous
stirring for 15 minutes. Subsequently, the reaction was stopped
to obtain a pale-yellow viscous liquid. The liquid was later blended with
starch/sorbitol or thermoplastic (TPS) to make the bioplastic composite.
Preparation
of TPS masterbatch
First, starch powder and sorbitol were
roughly mixed before being transferred into the torque rheometer (Toyoseiki,
Thermo Labo Plastomill 10c100-01). The blending temperature is 120°C, shaft
speed at 60 rpm, and duration is 5 min. The obtained starch/sorbitol blended
was then pelletized and labeled as TPS masterbatch.
Preparation
of the starch bioplastic composites
The desired amount of TPS masterbatch was
mixed with EPO at a content of 5.0% by
starch weight. Then the mixed paste was transferred to the torque rheometer
under the same TPS masterbatch blending condition. After that,
the obtained blending product was pelletized and thermo-shape forming using
compression molding (Toyoseiki, Mini Test Press10) at 120°C with a pressure of 15
MPa for 15 min. The molded composite bioplastic was kept for 2 days at 50-55%
relative humidity at room temperature prior to testing.
We carried out wide-angle X-ray diffraction experiments to confirm the effect of modifications on the crystal structure of tapioca starch by Automated Multipurpose X‑ray Diffractometer (XRD) (Equipment ID: (YG-601).
結果と考察 / Results and Discussion
As shown in Fig.1, native tapioca starch exhibits characteristic crystalline peaks at 10.3°, 11.5°, 15.3°, 17.5°, 18.0°, and 20.2°, indicating a C-type structure. Plasticization with sorbitol shifts the pattern to a V-type, with a dominant peak at 18.2°, due to single helical amylose complex formation. Hydrophobic components further promote V-type crystallinity. TS-1-CAES and TS-1-EPO show higher peaks than TS, suggesting increased crystallinity due to ESO hindering sorbitol-starch interactions. ESO does not create new crystalline structures but shifts the 18.2° peak to 18.4°, likely due to restricted chain mobility from ESO’s high molecular weight and hydrogen bonding with starch.
図・表・数式 / Figures, Tables and Equations
Fig. 1 XRD patterns of starch and composite starches with different blending process
その他・特記事項（参考文献・謝辞等） / Remarks(References and Acknowledgements)
成果発表・成果利用 / Publication and Patents
論文・プロシーディング（DOIのあるもの） / DOI (Publication and Proceedings)
口頭発表、ポスター発表および、その他の論文 / Oral Presentations etc.
特許 / Patents
特許出願件数 / Number of Patent Applications：0件
特許登録件数 / Number of Registered Patents：0件