Non-covalent in situ self-assembly of fruit peel waste into eco-friendly pectocellulosic bioplastics with high strength, flexibility and processability properties

Converting fruit peel wastes into degradable bioplastics has brought dawn to solve the severe plastic pollution and inefficient organic food waste management. However, it remains a challenge to convert peel wastes into bioplastics without decomposing their biocomponents. Furthermore, most of the bioplastics currently being researched have poor performance, especially in terms of trade-offing high strength, toughness, and good processability. Here, we utilize a noncovalent-mediated design to convert peel waste into pectocellulosic bioplastic that features the in situ ordered self-assembly of cellulose and pectin in the peel into a structure similar to a carboxylic acid dimer via hydrogen bonding. Benefiting from efficient energy dissipation mechanisms and reversible hydrogen bonding interactions, pectocellulosic bioplastics exhibit excellent mechanical properties (superior to most petrochemical-based and bio-based plastic materials), and can be molded into 2D/3D shapes or reprocessed into new plastics, realizing a combination of high strength (50.5 MPa), toughness (5.1 MJ/m³) and good processability. These bioplastics also combine biosafety (48 h cell viability > 85 %), biodegradability, and durability. Based on these characteristics, these pectocellulosic bioplastics can be considered as a candidate for petrochemical plastics, particularly suitable for some sensitive applications such as food inner packaging. Excitingly, the universality of this strategy in a variety of peel wastes has been verified. This work highlights the transformative potential of converting peel waste into valuable materials, providing a sustainable solution to plastic pollution and organic waste management.