近年來利用石化燃料生產的傳統塑膠製品(如PP，PE，PVC等)，對於環境的汙染不斷累積。為了改善污染的情況，改變使用的塑膠製品材質越發受到重視，而使用內酯作為原料，所生成之聚酯化合物，具有好的生物降解及生物相容性，受到生物醫學及工業上的重視，並逐漸取代傳統的不可降解塑膠。在開環聚合反應中，鋁金屬之地殼含量豐富、價格低廉及毒性相對低，釔金屬則是在聚合反應中容易具有較好的立體選擇性，所以兩者常被應用於開環聚合反應之金屬催化劑。本實驗透過合成釔金屬的起始物和錯合物，並透過1H NMR和滴定金屬含量，分析錯合物結構。並透過格林納試劑合成一系列鋁催化劑，在配位基上修飾不同推拉電子基，與不同立障的取代基，來調控催化劑之反應活性。透過不同溫度下，針對各個鋁催化劑對於ε-己內酯和δ –戊內酯進行開環聚合反應，並藉由動力學實驗，計算反應速率(kobs)和活化能。實驗結果發現，當取代基帶有拉電子基時，能提升鋁催化劑反應速率，同時維持好的分子量分佈度，可能原因為拉電子基會讓鋁金屬中心之路易士酸性增強，更有效的生成反應活性物種，加速反應進行，並透過配位基本身的立體效應，有效控制聚合物鏈之生成。;In recent years， the production of traditional plastic products (such as PP， PE， and PVC) using fossil fuels has led to a continuous accumulation of environmental pollution. To mitigate this pollution， changing the materials used in plastic products has become increasingly important. Polyester compounds produced using lactones as raw materials exhibit good biodegradability and biocompatibility， attracting attention in biomedicine and industry， and are gradually replacing traditional non-degradable plastics. In ring-opening polymerization， aluminum is abundant in the Earth′s crust， inexpensive， and relatively low in toxicity， while yttrium exhibits good stereoselectivity in polymerization reactions. Therefore， both are commonly used as metal catalysts in ring-opening polymerization. This experiment synthesized yttrium metal starters and complexes， and analyzed the structure of the complexes using 1H NMR and metal content titration. Furthermore， a series of aluminum catalysts were synthesized using Grinner reagents， and the reactivity of the catalysts was controlled by modifying the ligands with different push-pull electron groups and different barrier substituents. The ring-opening polymerization of ε-caprolactone and δ-valerolactone was carried out on various aluminum catalysts at different temperatures， and the reaction rate (kobs) and activation energy were calculated through kinetic experiments. The results showed that when the substituents contained electron-withdrawing groups， the reaction rate of the aluminum catalysts was increased while maintaining a good molecular weight distribution. This may be because the electron-withdrawing groups enhance the acidity of the Lewisite at the aluminum metal center， more effectively generating reactive species， accelerating the reaction， and effectively controlling the formation of polymer chains through the steric effect of the ligands themselves.
