Multifunctional interface engineering: Tailoring mechanical and UV-resistant properties of PLA/PBAT-based composites...

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Biodegradable polymers like poly(lactic acid) (PLA) and poly(butylene adipate-co-terephthalate) (PBAT) are promising for sustainable medical materials.
• Challenges include poor interfacial compatibility in blends and lack of functional properties like UV resistance, limiting applications in medical packaging.
• Developing advanced composites with enhanced properties is crucial for expanding their use in demanding medical fields.

Purpose of the Study:

• To develop a multifunctional compatibilizer for improving poly(lactic acid)/poly(butylene adipate-co-terephthalate) blends.
• To enhance interfacial adhesion, mechanical properties, and introduce UV resistance to the polymer blend.
• To explore the potential of epoxy-functionalized carbon dots (OCDs) in creating advanced biodegradable composites for medical applications.

Main Methods:

• Interfacial engineering using epoxy-functionalized carbon dots (OCDs) as a compatibilizer for PLA/PBAT blends.
• Melt processing to induce in-situ ring-opening reactions between OCD epoxy groups and polymer terminal groups, forming covalent bridges.
• Characterization of mechanical properties (tensile strength, modulus), UV absorption, thermal degradation, and melt strength of the resulting composites.

Main Results:

• OCDs significantly improved interfacial adhesion between PLA and PBAT through covalent bonding.
• Optimal composite formulations showed a 47.7% increase in tensile strength and a 23.4% increase in tensile modulus.
• Exceptional UV resistance was achieved, with absorption intensities enhanced by up to 775%; modified thermal degradation and improved melt strength were also observed.

Conclusions:

• Multifunctional OCDs effectively compatibilize PLA/PBAT blends, creating robust covalent linkages.
• The resulting composites exhibit significantly enhanced mechanical properties and excellent UV resistance.
• These advanced biodegradable composites show great potential for use in demanding medical applications, particularly in packaging.