Polyurethane (PU) is among the most universal polymers and has been extensively applied in many fields, such as construction, machinery, furniture, clothing, textile, packaging and biomedicine. Traditionally, as the main starting materials for PU, polyols deeply depend on petroleum stock. From the perspective of recycling and environmental friendliness, advanced PU synthesis, using diversified resources as feedstocks, aims to develop versatile products with excellent properties to achieve the transformation from a fossil fuel-driven energy economy to renewable and sustainable ones. This review focuses on the recent development in the synthesis and modification of PU by extracting value-added monomers for polyols from waste polymers and natural bio-based polymers, such as the recycled waste polymers: polyethylene terephthalate (PET), PU and polycarbonate (PC); the biomaterials: vegetable oil, lignin, cashew nut shell liquid and plant straw; and biomacromolecules: polysaccharides and protein. To design these advanced polyurethane formulations, it is essential to understand the structure–property relationships of PU from recycling polyols. In a word, this bottom-up path provides a material recycling approach to PU design for printing and packaging, as well as biomedical, building and wearable electronics applications.

A composite material based on a new insect-based grasshopper protein (GP)/soy protein isolate (SPI) blend has been studied by solution casting using xylose as a crosslinker and cinnamaldehyde (CIN) as an antimicrobial agent to develop a novel antimicrobial edible packaging. In this paper, the effects of SPI, xylose, and CIN content on the properties of edible film were studied. The tensile test confirmed that 30% SPI incorporation content had the best blending effect with the mechanical properties and barrier properties improving obviously. After adding 10% xylose to form crosslinking network, the tensile strength and elongation at the break of the film showed the best state increasing to 3.4 Mpa and 38%, respectively. The 30% CIN enabled the film to be resistant to Escherichia coli and Staphylococcus aureus strongly and decreased the water vapor permeability to 1.8 × 10¹¹ (g/cm·s·Pa) but had a negative effect on the mechanical properties. This is the first time that edible insects have been used to produce the natural edible antimicrobial packaging, proving edible insects, an excellent protein source, are tipped to be a potential source of raw materials for biomaterials.