• 最佳库匹配: 聚乳酸 #746

• 低波数谱带（690和753 cm⁻¹）无法根据现有证据可靠地归属于特定的PLA振动；它们可能代表骨架模式或微量杂质。
• 3501 cm⁻¹处的宽O–H吸收可能源于吸收的大气水分；因此，其强度可能随样品处理而变化。

推荐的后续步骤: 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.