Synthesis and Characterization of Functionalized Polylactides Containing Acetal Units

Area of Science:

• Polymer Chemistry
• Materials Science
• Organic Synthesis

Background:

• Polylactide (PLA) is a widely used biodegradable polyester.
• Functionalizing PLA is crucial for tailoring its properties and applications.
• Controlled introduction of specific units into the polymer backbone remains a challenge.

Purpose of the Study:

• To synthesize novel functionalized lactide copolymers with tunable acetal units.
• To investigate the controlled preparation of these copolymers with regulated functional group content.
• To explore the impact of acetal units on copolymer degradability and potential for post-modification.

Main Methods:

• Synthesis of functionalized cyclic acetals (allyl- and chloro- functionalized) via paraformaldehyde reaction with diols.
• Cationic copolymerization of synthesized cyclic acetals with lactide using glycol initiator and triflic acid catalyst.
• Characterization of copolymer structure and molar mass using NMR (1H, 13C, 2D) and size-exclusion chromatography.

Main Results:

• Successfully prepared functionalized lactide copolymers with controlled acetal unit content (5-27%).
• Demonstrated the ability to introduce reactive pendant groups (allyl, chloro) into the polyester backbone.
• Confirmed the potential for post-modification of functionalized copolymers via reactions with sodium azide and propanethiol.

Conclusions:

• The developed method allows for controlled synthesis of functionalized lactide copolymers.
• The acetal units influence material degradability and provide sites for chemical modification.
• This approach significantly expands the library of polylactide-based materials with tunable properties.