Development of energy-saving and labor-saving controlled-release repellents using supercritical carbon dioxide

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K00618
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Environmental conscious materials and recycle
• Research Institution: Niihama National College of Technology
• Principal Investigator: Tsutsumi Chikara 新居浜工業高等専門学校, 生物応用化学科, 准教授 (00300640)
• Project Period (FY): 2016-10-21 – 2019-03-31
• Keywords: 環境適応型ポリマー / ポリ乳酸共重合体 / 超臨界二酸化炭素 / 徐放剤 / 忌避剤

Outline of Final Research Achievements

Impregnation experiments with the essential oil using supercritical carbon dioxide (scCO2) showed that films of poly(L-LA-ran-VL) did not dissolve up to 120°C. The oil content of the poly(L-LA-ran-VL) (73/27) was much higher than those of the other specimens, with especially high oil concentrations at 100 and 120°C. During hydrolysis using a phosphate buffer solution at pH 7.0, the oil vapor released upon degradation of the copolymer was measured.
Changes in the Tm and Tg of poly(L-LA-ran-VL) specimens processed with scCO2 were evaluated. The 73/27 specimen, having the lowest Tm, exhibited increases in this value with increases in the scCO2 processing temperature. The ΔHm values of the poly(L-LA) and poly(L-LA-ran-VL) samples before processing were relatively high and were further increased with increases in the processing temperature.

Free Research Field

高分子化学、環境学

Academic Significance and Societal Importance of the Research Achievements

農作物などへの害虫・鳥獣類やカビなどの対策として、これまでにない省エネ・省力型の徐放性忌避剤を開発するために本研究では生分解性ポリマーへ樹木精油を超臨界二酸化炭素（scCO2）による含浸実験を行い、その薬剤の徐放性も評価した。これまでのscCO2による含浸ではその処理過程において、基材となるポリマーが一部融解する問題があったが、ポリマーを改良することによりその問題を改善することができた。また、scCO2処理がポリマーの構造に及ぼす影響についても評価し、ポリマーの結晶化が促進することがわかった。