Integrated Design Enabling High‑Performance and Marine‑Degradable Bioplastics

    Marine plastic pollution continues to escalate, with large amounts of short‑lived plastics entering oceans and fragmenting into microplastics that threaten ecosystems and human health. Although PLA is biodegradable in composting environments, it remains highly persistent in seawater due to low temperature, limited microbial activity, and restricted water diffusion. Achieving practical marine degradability requires molecular‑level control of hydrophilicity, crystallinity, chain mobility, and enzymatic accessibility while preserving mechanical durability.
    This work presents a unified molecular‑design strategy for marine‑adaptive bioplastics by combining hydrophilic pathways, controlled block sequences, and biomass‑derived monomers. PEG–PLA multiblock copolymers show that hydrophilic segments create water‑penetration routes that accelerate hydrolysis and enzymatic degradation, enabling 50–70% seawater biodegradation within 28 days. Xylose‑derived PAX‑co‑PLA copolymers demonstrate how biomass‑based segments provide toughness while allowing controlled degradation; PHX‑co‑PLA loses structural integrity within one month in seawater yet maintains low water uptake. Together, these materials reveal general principles for designing next‑generation marine‑degradable bioplastics: hydrophilic pathways that enhance seawater penetration, block‑sequence control that tunes toughness and degradation, and biomass‑derived monomers that improve functionality without increasing environmental burden. This integrated approach enables precise adjustment of degradation rates and mechanical performance, offering a promising route toward sustainable materials capable of mitigating marine plastic pollution.