【公開日：2024.07.25】【最終更新日：2024.07.22】
課題データ / Project Data
課題番号 / Project Issue Number
23YG0056
利用課題名 / Title
新しい高分子材料の設計と開発
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
Soybean based Epoxy, Thermoplastic, Composite, Tapioca Starch,成形/ Molding,異種材料接着・接合技術/ Dissimilar material adhesion/bonding technology,高強度・生分解性プラスチック/ High-strength, biodegradable plastic,バイオアダプティブ材料/ Bioadaptive materials,生分解性材料/ Biodegradable material,X線回折/ X-ray diffraction,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)
The mechanical properties (e.g. tensile strength and elongation) of the starch film are depended on the crystalline behavior change when cooperated with another polymer. This research prepared epoxy oligomer from epoxidized soybean oil crosslink with citric acid. This oligomer will be further blended with starch to investigate the mechanical change with structure relation. The different compounding processes between starch and epoxy oligomer were studied. To characterize the crystalline of starch/epoxy oligomer composites, XRD technics is play an important role to obtain the essential data to understand the crystalline structure.
実験 / Experimental
MaterialsNative tapioca starch (NTS, 10%moisture content) was provided by SMS Corporation Co., Ltd., Thailand. Sorbitol and CA (3 carboxylic group/mole) were purchased from Fujifilm Wako Pure Chemical Co., Ltd., Japan. ESO (~3.9 epoxide group/mole) was purchased from Sanwa Synthetic Chemical Co., Ltd.Preparing crosslinked epoxidized soybean oil (CES) The equimolar ratio between epoxides and carboxylic acid groups was used. First, 2.70 g CA wasdissolved in 0.37 ml distilled water and then heated to 90 oC. 10 g ESO was heated to 90 oC, then mixed the CA solution with ESO with vigorous stirring for 15min. Then the reaction was stopped to obtain a pale-yellow viscous liquid. This liquid was immediately blended with starch/sorbitol or TPS.Preparation of thermoplastic starchFirst, NTS and sorbitol were mixed with or without additives roughly. Then, the sample was dry blended using Internal mixing (Toyoseiki, Thermo Labo Plastomill 10c100-01) at 120 °C mixing speed 60 rpm for 5 min2. The blended sample was pelletized with further molding for testing. The sample without additives was referred to as a control (TPS) sample. The CAES sample and CES sample indicate the NTS/sorbitol mixed with non-reacted CA/ESO or crosslinked epoxidized soybean oil as additives before dry blending, respectively. The additives amount was 5 wt% calculated based on NTS. To observe the blending step affects the final product. The sample was prepared by 2-step blending. The obtained pelletized control (TPS) sample was mixed with CES, followed by dry blending. This sample was referred to as TPS-CES sample. The pelletized sample was pressed molding to obtain film sample using a press machine (Toyoseiki, Mini Test Press10 ) at 120 oC with a pressure of 15 MPa for 15 min. The sample was kept at room temperature with 50-55 %RH for 2 days before testing. A change in crystal structures has a significant effect on the physical properties of the thermoplastic composites. The wide-angle X-ray diffraction (WAXD) is a powerful tool for analyzing such structural changes. We used WAXD (全自動多目的X線回折装置: 装置ID: YG-601) to analyze the crystallinity of starch.
結果と考察 / Results and Discussion
The weight ratio of starch to sorbitol was selected at 60/40 wt% to investigate the influence of additives on the TPS final product. The scanning electron microscopy (SEM) and polarized optical microscopy (POM) images show the good plasticization of sorbitol from the control sample with the small number of starch granules, as seen by the presence of maltese cross patterns in the POM images. CAES and CES samples show poor mechanical properties, as shown in Figure 1, due to sorbitol undergoing ring-opening reactions with epoxide groups as well as esterification reactions with CA3. In addition, CES oligomers contain remaining functional groups that can react with sorbitol. Hence, inhibiting starch plasticization, resulting in a high number of starch granules in the final product. To investigate the influence of crosslinked and uncross-linked epoxy, The results show that the CAES sample exhibits a slightly higher elongation, while the CES sample exhibits a 97% higher tensile strength. This indicates an effective interaction between oligomers with starch/sorbitol blended in compared to uncross-linked CAES. The TPS-CES sample shows a good compatibility between the TPS matrix and CES. This is caused by the ability of the oligomers to form bonds easily with the hydroxyl group of starch and sorbitol after starch was plasticized, leading to a reduced number of starch granules. TPS-CES sample shows the elongation with a significant increase of 55%. Figure 2 shows XRD patterns of a) original starch, b) starch plasticized with sorbitol, and c) 5 wt% epoxy oligomer blended starch film. The crystallinity of starch when plasticized with sorbitol was decreased. The C-type crystalline of the original starch changed to Vh-type crystalline due to heat and shear from processing. Interestingly. when epoxy oligomer was applied, the Vh-type peak tended to shift towards a higher diffractive angle. This might explain why the higher molecular weight of oligomer compared to sorbitol will be occupied to free volume space in the starch matrix. This behavior can be confirmed by SEM images of composite film which the size of plasticized starch granules is smaller than starch film without oligomer.
図・表・数式 / Figures, Tables and Equations
Figure 1 Mechanical properties of TPS samples.
Fig 2. XRD patterns of a) original starch, b) starch plasticized with sorbitol and c) 5 wt.% epoxy oligomer blended starch film.
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.
- Pansuwan Thanaboon, 宮田 剣,"エポキシ化大豆油を添加剤としたタピオカ澱粉熱可塑性複合材料の開発", プラスチック成形加工学会第31回秋季大会, 2023年11月29日
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