Bioplastic material from microalgae : Extraction of starch and PHA from microalgae to create a bioplastic material

Sammanfattning: Microalgae used in sewers to capture CO2 eventually turns into waste material. Through the use oftheir biomass, the waste algae can be given a new purpose. In this study attempts to extract starch or PHA from three different algae; Calothrix Scytonemicola, Scenedesmus Almeriensis and Neochloris Oleoabundans, were made. We also attempted to create a bio-based plastic material. Both Scenedesmus Almeriensis and Neochloris Oleoabundans are starch rich microalga. By washing with acetone, cryo grinding, use of ultrasonic homogenizer and dialysis, starch was likely extracted successfully. The extracted material and the plasticiser Carboxymethyl Cellulose (CMC) was used to cast plastic film. The cast film was very thin and brittle; perhaps by using different plasticisers or additives a more usable bio-based plastic material can be created. The PHA rich algae Calothrix Scytonemicola was used to extract PHA. The algae was washed with acetone, cryo grinded and then mixed with Sodium Hypochlorite(aq) and deionised water to extract the desired PHA. Due to a shortage of algae very small amounts of material could be extracted. Therefore, the casting of a plastic film was performed with commercial PH3B, which is a type of PHA. Three attempts were conducted. The first one with only chloroform, the second one with CMC and chloroform and the last one with Sucrose Octaacetate and chloroform. The film with Sucrose Octaacetate gave the best plastic material in regards to mechanical properties.