Biopolymer polylactic acid

Pang, et al., Biotechnol. J. 2010, 5, 1125–1136

Polylactide (PLA) is a biodegradable, aliphatic polyester derived from lactic acid. It has similar mechanical properties to polyethylene terephthalate, but has a significantly lower maximum continuous use temperature. PLA products can be recycled after use, either by remelting and processing the material a second time or by hydrolyzing to lactic acid, the basic chemical. In this review by scientists from Changchun, China, technologies for polymerization of lactic acid and comparison of physical, thermal, and mechanical properties, biodegradability, and biocompatibility of the PLA and copolymers with other similar polymers are described.

Biopolymer 1,3-propanediol

Liu et al., Biotechnol. J. 2010, 5, 1137–1148

1,3-Propanediol (PTT) is the organic compound with the formula CH2(CH2OH)2. This three-carbon diol is a colorless viscous liquid that is miscible with water. It is mainly used as a building block in the production of polymers such as polytrimethylene terephthalate (PDO). PDO can be formulated into a variety of industrial products including composites, adhesives, laminates, coatings, moldings, aliphatic polyesters, and copolyesters. It is also a solvent and used as an antifreeze and wood paint. Authors from Tsinghua University show that by using engineered E coli, 135 g/L PDO can be obtained with glucose as feedstock. Since the bio-process of PDO production consumes 40% less energy and reduces greenhouse gas emissions by 20% versus petroleum-based propanediol, the bio-based polyester PTT is more environmentally friendly and sustainable compared with fossil fuel-based polymers.

Biopolymer poly (butylene succinate)

Xu and Gu, Biotechnol. J. 2010, 5, 1149–1163

Poly (butylene succinate) (PBS) is synthesized from succinic acid and butanediol and fully biodegradable. PBS can be applied for packaging, disposable plastics, agricultural films and in biomedicine. In this article by scientists from Beijing, China, production of the monomers, synthesis, processing and properties of PBS and its copolymers are reviewed. The physical properties and biodegradation rate of PBS materials can be varied in a wide range through copolymerization with different types and various contents of monomers. PBS has a wide temperature window for thermoplastic processing, which makes the resin suitable for extrusion, injection molding, thermoforming and film blowing. Finally, the authors summarize industrialization and applications of PBS.