Fabrication of Novel Functional Cell‐Plastic Using Polyvinyl Alcohol: Effects of Cross‐Linking Structure and Mixing Ratio of Components on the Mechanical and Thermal Properties

The current system of disposal of plastic materials fabricated from petroleum‐based resources causes serious environmental pollution. To solve the problem, a bioplastic called “cell‐plastic” is developed, in which unicellular green algal cells serve as a fundamental resource. This approach converts CO(2) in the atmosphere directly into plastic products by exploiting the photosynthetic‐driven proliferation of algal cells. Herein, cell‐plastic films are fabricated using biodegradable and water‐soluble polyvinyl alcohol (PVA) as a matrix, in which the effects of a cell‐to‐matrix mixing ratio and the chemical structure of the matrix on the mechanical and thermal properties are investigated. As a method of the chemical structural change, a cross‐linking structure is introduced to the matrix by connecting hydroxy groups of PVA using aldehyde. The tensile tests reveal that the PVA‐cell‐plastic film maintains the mechanical properties of PVA film. Moreover, a cross‐linked cell‐plastic film exhibits high water absorption, making it suitable as a functional cell‐plastic material.