Polyhydroxyalkanoates (PHA) have been produced by several bacteria as bioplastics in industrial scales. PHA commercialization has been challenging due to its complexity and the associated high cost together with instabilities on molecular weights (Mw) and structures, thus instability on thermo- and mechanical properties. PHA high production cost is related to complicated bioprocessing associated with sterilization, low conversion of carbon substrates to PHA products, and poor growth of microorganisms as well as complicated downstream separation. To reduce complexity of PHA production, robust microorganisms that are contamination resistant bacteria have been targeted especially extremophiles, developments of engineering approaches for extremophiles especially Halomonas spp. for better PHA production have been successfully conducted and termed as “next generation industrial biotechnology” (NGIB). Diverse PHA can also be produced by engineering Halomonas or Pseudomonas spp. This review introduces recent advances on engineering bacteria for enhanced PHA biosynthesis and diversity.

This paper reviews the recent development of starch-based materials, including both fundamental and application researches. In order to overcome the weakness of pure starch-based materials, such as lower mechanical properties found in natural polymers and moisture sensitivity, various blends and composites have been developed in the last two decades. In practical, incorporation of any additives is sensitive in developing fully biodegradable starch-based materials. Furthermore, safety issues will be considered as priority regarding any additives for food packaging applications. Based on these concerns, various natural filler and edible reinforce agents, such as natural fibers, starch or cellulous crystals, and laver, have been used in starch-based materials. So-called self-reinforced techniques, reinforcing starch matrix by modified starch particles, have also been used in developing starch-based composites. During developing starch-based foams the unique function of water, acts as both plasticizer and blow agent for starch-based foam, has been systematically studied. So far, various conventional processing techniques such as extrusion, injection, compression molding, casting and foaming, as well as some new techniques such as reactive extrusion, have been adapted for processing starch-based polymeric materials. Various starch-based products have been developed and commercialized.

A significantly growing interest is to design new biodegradable polymers in order to solve fossil resources and environmental pollution problems associated with conventional plastics. A kind of new biodegradable polymers, aliphatic–aromatic co-polyesters have been researched widely and developed rapidly in recent years, since that can combine excellent biodegradability provided from aliphatic polyesters and good properties from aromatic polyesters. Out of which, poly (butylene-adipate-co-terephthalate) (PBAT) shows the most importance. PBAT has been commercialized by polycondensation reaction of butanediol (BDO), adipic acid (AA) and terephthalic acid (PTA) using general polyester manufacturing technology. And it has been considered to have desirable properties and competitive costs to be applied in many fields. Therefore, this review aims to present an overview on the synthesis, properties and applications of PBAT.

Recently, the demands for biodegradable and renewable materials for packaging applications have increased tremendously. This rise in demand is connected to the growing environmental concerns over the extensive use of synthetic and non-biodegradable polymeric packaging, polyethylene in particular. The performance of biodegradable polymers is discussed in this review, with a particular focus on the blends of starch and other polymers. Furthermore, in food packaging industry, microbial activities are of great concern. Therefore, incorporation of antimicrobial agents or polymers to produce barrier-enhanced or active packaging materials provides an attractive option for protecting food from microorganism development and spread. Additionally, the barrier, mechanical and other properties of biodegradable polymers are discussed. Lastly, the existing and potential applications for bioactive coatings on antimicrobial packaging materials are also addressed.

This paper focuses on the development of polyvinylidene fluoride microfoam by implementing a chemical blowing agent through a continuous process. The objective was to investigate the effects caused by varying concentrations of chemical blowing agent, the use of a master batch as formulation variables, and variation of die temperature on the properties of polyvinylidene fluoride foam produced continuously. By using a 10% master batch formulation (contains 2% chemical blowing agent in final product), the cell density was increased while the cell size and foam density were decreased; the average cell size, cell density, and void fraction were found to be 50 μm, 7.7 × 10⁶ cells/cm³, and 33%, respectively. This is due to the increased cell density primarily due to the increased nucleation sites. At a lower chemical blowing agent, concentration of 1%, the die temperature was varied over a range of 125-145 °C, as this is approximately the melting point of the polyvinylidene fluoride. Decreasing the die temperature from 135 °C to 130 °C caused the cell density to increase and cell size to decrease, while void fraction decreased from 58% to 39%. This is due to the loss of melt strength upon increasing the temperature of the melt PVDF as it exits the die.