Conversion of Macroalgae into Environmentally Friendly Bioplastics by Noncovalent Bond Assembly

In response to the current ecological crisis and oil depletion crisis, the use of macroalgae to produce biodegradable bioplastics that can replace petrochemical materials has attracted widespread attention. Herein, a multiscale interfacial engineering strategy for “in situ regeneration” of lignin is proposed to prepare a Bioplastic using Enteromorpha prolifera biomass components featuring hydrogen-bonding-mediated self-assembly of micro/nano lignin and cellulose micro-/nanofibers into a multistage composite dense layer structure. The prepared bioplastics exhibit good mechanical strength (12.80 MPa), superior to most films prepared from algae and even comparable to some common petrochemical plastics. They have a high water contact angle (94.04°) and do not deform or disintegrate when immersed in water for 60 d, demonstrating excellent hydrophobicity and water stability. Bioplastics can block the entire spectrum of UVB (275–320 nm) and UVC (200–275 nm), as well as most of the UVA spectrum (320–400 nm), providing good UV resistance. Importantly, they are biodegradable, compostable, and recyclable, exhibiting unique closed-loop cycle properties. Finally, the environmental impacts were assessed in terms of global warming potential, ecotoxicity, ozone depletion, and other perspectives through life-cycle assessment, emphasizing the environmental benefits of using macroalgae for bioplastic production. This environmentally friendly Bioplastic can be regarded as a substitute for petrochemical plastics and holds great promise in areas such as packaging materials.