Cyclo.Plas 2: A Dual Focus Development as Alternative Materials to Plastic by Upcycling Fish Scale Waste Components

Using the biomimicry of fish scale composition, calcium salts and collagen, Cyclo.Plas 2 (CP2) is a dual-focus materials development addressing plastic degradability and waste accumulation. The biomineralisation concept was applied to valorise 3D-printed polylactic acid (PLA) waste with a fish scale-inspired mineral, hydroxyapatite (HAp), to form composites. It was found that the composites exhibited greater flexural strength compared to 3D-printed PLA waste and had faster degradation in hydrolysis, home composting and acidic environments. Following the sclerotisation concept, the physicochemical properties of intact collagenous matrix of fish scale waste were enhanced to form a thin, plastic-like material. These thin films were comparable to low-density polyethylene (LDPE), with high transparency and shrinkage performance. Samples biodegraded after 8 weeks with no phytotoxicity and enhanced plant growth. Trials showed improved thermal stability and water resistance, yet the samples degraded with low total dissolved solids. Cyclo.Plas 2 serves as a preventative and practical disposal solution to promoting a circular economy through home composting.