Flexible and Recyclable Bio-Based Polyester Composite Films with Outstanding Mechanical and Gas Barrier Properties...

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Petroleum-based plastics face resource depletion and environmental concerns.
• Developing high-performance, sustainable plastic alternatives is crucial.
• Polyesters require enhanced mechanical and gas barrier properties for broader applications.

Purpose of the Study:

• To create high-performance, bio-based polyester composite films.
• To enhance mechanical strength, toughness, and gas barrier properties.
• To develop a recyclable and competitive plastic substitute.

Main Methods:

• Fabrication of composite films using bio-based PBF polyester matrix and "leaf-shaped" carbon nanotube@boron nitride nano-sheet (CNT@BNNS) covalent hetero-junctions.
• Utilized an "in-situ polymerizing and hot-pressing" strategy.
• Investigated the effect of covalently hetero-structured CNT@BNNS fillers on material properties.

Main Results:

• The fabricated CNT@BNNS/PBF (CBNP) composites exhibited excellent mechanical properties: 76 MPa strength, 2.3 GPa modulus, 85 MJ m^-3 toughness, and 193% elongation at break.
• Achieved superior gas barrier properties: 0.015 barrer for O₂ and 1.1 × 10^-14 g cm cm^-2 s^-1 Pa^-1 for H₂O.
• The covalent structure of CNT@BNNS enhanced stress transfer and physical barrier effects, suppressing filler re-stacking.

Conclusions:

• The developed CBNP composites demonstrate significantly improved performance compared to pure PBF and most engineering plastics.
• The materials offer a viable, recyclable alternative to conventional plastics, addressing the performance-recyclability tradeoff.
• This work presents a promising pathway for sustainable polyester-based plastic substitutes.