Provided are a straw-based modified biofilm, and a preparation method and use thereof. In the method, crop straw is liquefied into a mixed organic solvent-biological polyol, and then the biological polyol is used as a cross-linking agent to cross-link and couple a native crop straw. A curing agent is added during the cross-linking and coupling, thereby obtaining the straw-based modified biofilm.

The present disclosure includes Sargassum-based polymer composite filaments for 3D printing having (1) a higher content of algae biomass as compared with commercially available algae-based filaments, and (2) enhanced 3D printer bed adhesion and biodegradability as compared to polylactic acid (PLA) filaments.

A method of making a bio-based cellular plastic comprises obtaining pellets of a non-cellular plastic having a density less than 1 g/cm.sup.3; obtaining an algae product having a density greater than 1 g/cm.sup.3; injection molding the plastic pellets and the algae product including introducing a chemical blowing agent, a physical blowing agent, or both; and producing a bio-based cellular plastic having a density equal to or less than 0.98 g/cm.sup.3.

The object of the present invention is to provide a production method which makes it possible to obtain a PHA with a simple operation. The object can be attained by providing a method for producing a polyhydroxyalkanoate, the method including the steps of: (a) preparing an aqueous polyhydroxyalkanoate suspension having a pH of not more than 7; and (b) heating the aqueous polyhydroxyalkanoate suspension, prepared in the step (a), at a temperature set at 80 C. to 300 C. in a twin screw extruder so as to aggregate a polyhydroxyalkanoate.