• 最佳庫匹配: 聚乳酸 #746

• 低波數帶（690和753 cm⁻¹）無法根據現有證據可靠歸屬於特定的PLA振動；它們可能代表骨架模式或微量雜質。
• 3501 cm⁻¹處的寬O-H吸收可能來自吸附的大氣水分；因此，其強度可能隨樣品處理而變化。

建議的下一步: Acquire a reference spectrum of pure PLA processed under the same conditions (e.g., ATR crystal, film thickness) to confirm the overall profile. Use DSC or TGA to verify the characteristic glass transition (~55–60 °C) and melting point (~150–160 °C) of PLA. If the O–H band at 3501 cm⁻¹ remains prominent after thorough drying, consider end-group analysis by NMR or titration to assess degree of hydrolysis or molecular weight.