Global demand for polymers such as plastics is expected to quadruple to about 1bn tonnes a year by 2050. However, petrochemicals currently used in plastic production are costly and have an impact on the environment.

Recently, researchers in Europe reported the first synthesis of a fully renewable polyester: Lucia Gardossi and her team at the university of trieste in Italy have produced a renewable polyester from an enzyme-catalyzed polymer. The researchers paid particular attention to the substance's sustainability during their study.

"We chose the biotype monomer produced by microbial fermentation of sugar as the raw material and fixed the enzyme (a biodegradable protein) to the rice hull as the catalyst for the polymerization," says Gardossi. In addition to using renewable materials and catalysts, the researchers were able to achieve solvent-free polymerization at 50°C, while similar reactions typically require metal catalysis at 150°C.

After in-depth research and calculation, Gardossi team selected the cracking dissolve cellulose enzyme (Thermobifida cellulosilytica, Thc_cut1) the enzyme can be oxalic acid and 1, 4 butanediol into polyester. "We use novel bioinformatics methods to select enzymes scientifically and rationally, and use multivariate statistical methods to optimize the enzyme production process," says Gardossi.

ThomasFarmer, an expert in sustainable chemistry at the university of york in the UK, praises the "holistic approach" used by Gardossi's team, which is not mysterious, but too many researchers specialise in optimizing the synthesis process in one area in order to gain green credentials. Thomas added: "this study, which includes bioinduced monomers and solvent-free conditions, is a classic example of how green chemistry can be applied to all aspects of production. Exploration and efforts like this will drive the future of truly sustainable polymers."