Modification Strategies and Film Fabrication of CO ₂ -Derived Poly(propylene carbonate phthalate) for High-Performance Gas Barrier Applications

Poly-(propylene carbonate phthalate) (PPC-P) is a promising biodegradable material exhibiting excellent gas barrier properties; however, its inherent brittleness limits its practical applications. To address this limitation, we prepared and systematically investigated a series of PPC-P/poly-(ethylene oxide) (PEO) blends and PPC-P/PEO/ADR composites. Comprehensive characterization was performed by using tensile testing, scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis (TGA), gas permeability analysis, and contact angle measurements. The results demonstrate that PEO incorporation substantially enhances the ductility of PPC-P, albeit at the expense of reduced tensile strength and compromised gas barrier performance. Through the addition of ADR4468 and optimization of the composition to PPC-P:PEO/ADR4468 = 92 wt %:8 wt %:0.6 wt %, we achieved an optimal balance of mechanical properties, yielding a tensile strength of 20.13 MPa coupled with an exceptional elongation at break of 407.63%. Notably, the ADR4468-modified composite exhibited superior barrier properties, with measured permeabilities of 4592 cm³·μm/(m²·day) for CO₂, 1297 cm³·μm/(m²·day) for O₂, and 289 mg·μm/(m²·day) for water vapor. The modified material also displayed enhanced thermal stability, as evidenced by a 5% weight loss temperature of 247.57 °C, along with improved surface hydrophilicity that effectively suppresses water droplet nucleation while maintaining optical clarity. This work provides significant insights into the strategic modification of PPC-P and demonstrates its potential for developing high gas barrier applications.