Counterintuitive Compatibilization of Poly(δ-valerolactone) and Poly(l‑lactic acid) by Statistical Copolymers toward...

Area of Science:

• Polymer Science
• Materials Science
• Sustainable Chemistry

Background:

• Plastic waste accumulation is a global environmental challenge.
• Bioderivable and recyclable polymers like poly-(δ-valerolactone) (PVL) and poly-(l-lactic acid) (PLLA) offer sustainable alternatives.
• Blending immiscible polymers can create materials with synergistic properties, but achieving miscibility is crucial.

Purpose of the Study:

• To compatibilize immiscible blends of PVL and PLLA using various agents.
• To investigate the influence of compatibilizers on blend morphology, thermal, mechanical, and crystalline properties.
• To establish end-of-life pathways including biodegradation and chemical recycling for the developed blends.

Main Methods:

• Compatibilization of PVL/PLLA blends using thermoplastic starch, statistical copolymers (SCPs), and block copolymers.
• Characterization via scanning electron microscopy (SEM), thermal analysis (DSC/TGA), mechanical testing, and X-ray scattering (SAXS/WAXS).
• Molecular dynamics simulations to understand interfacial interactions.
• Evaluation of biodegradation and chemical recycling processes.

Main Results:

• Successful compatibilization of PVL/PLLA blends was achieved with different agents.
• Compatibilizers influenced microdomain size, affecting thermal and mechanical properties.
• X-ray scattering revealed the impact of compatibilizers on crystalline phases.
• Molecular dynamics simulations provided insights into polymer-interfacial interactions.
• Demonstrated viability for industrial composting, chemical recycling to esters, and depolymerization to lactone precursors.

Conclusions:

• Several PVL/PLLA blends show promise as high-performance sustainable materials.
• Statistical copolymers (SCPs) exhibited an unexpected compatibilization effect.
• The study establishes multiple viable end-of-life options for these advanced polymer blends.
• This work contributes to developing circular economy solutions for plastics.