傳統利用石化燃料生產的塑膠製品，對於環境的汙染已日趨嚴重。而使用內酯作為原料，所生成之聚酯化合物，具有好的水解性、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。但在開環聚合反應中，簡單路易士酸不一定能有效控制每條聚合物鏈長相等，或是平均分子量的高低。必須透過改變催化劑上取代基之電子效應和立體障礙，提升催化劑活性並減少未受控反應發生，達到良好的控制性。本研究透過格林納試劑修飾鋁錯合物，生成一系列催化劑，並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。;Plastics derived from conventional petrochemical processes have increasingly contributed to severe environmental pollution. As an alternative, polyesters synthesized from lactones exhibit advantageous properties, including hydrolytic degradability, biodegradability, and biocompatibility, thereby attracting significant attention from both biomedical and industry. These materials are progressively being considered as substitutes for traditional petroleum-based plastics. However, in the ring-opening polymerization (ROP) of lactones, simple Lewis acid catalysts often fail to achieve precise control over polymer chain length and molecular weight distribution. In this study, a series of aluminum-based catalysts were synthesized through Grignard reagent modification, introducing ligands bearing various electron-donating and electron-withdrawing substituents, as well as groups with differing steric hindrance. Kinetic studies were conducted to determine the observed rate constants (kobs) and activation energies, enabling a quantitative assessment of catalyst performance. The experimental results revealed that catalysts bearing electron-withdrawing substituents exhibited significantly enhanced reaction rates while maintaining narrow molecular weight distributions. This enhancement is attributed to the increased Lewis acidity of the aluminum center induced by the electron-withdrawing groups, which facilitates the formation of the active species and accelerates the polymerization process. Furthermore, the steric effects introduced by the aryl substituents were found to contribute to effective regulation of polymer chain propagation.
