Youngjae Byun

Improved thermal stability of polylactic acid (PLA) composite film via PLA-β-cyclodextrin-inclusion complex systems.

The effects of the incorporation of PLA-β-cyclodextrin-inclusion complex (IC) and β-cyclodextrin (β-CD) on biopolyester PLA films were investigated. Thermal stability, surface morphology, barrier, and mechanical properties of the films were measured at varying IC (1, 3, 5, and 7%) and β-CD (1 and 5%) concentrations. The PLA-IC-composite films (IC-PLA-CFs) showed uniform morphological structure, while samples containing β-CD (β-CD-PLA-CFs) showed high agglomeration of β-CD due to poor interfacial interaction between β-CD and PLA moieties. According to the thermal property analysis, the 5% IC-PLA-CFs showed 6.6 times lower dimensional changes (6.5%) at the temperature range of 20-80°C than that of pure PLA film (43.0%). The increase of IC or β-CD content in the PLA-composite films shifted the glass transition and crystallization temperature to higher temperature regions. The crystallinity of both composite films improved by increasing IC or β-CD content. Both composite films had higher oxygen and water vapor permeability as IC or β-CD content increased in comparison to pure PLA film. All the composite films had less flexibility and lower tensile strength than the pure PLA film. In conclusion, this study shows that the IC technique is valuable to improve the thermal expansion stability of PLA-based films.

Utilization of Bioplastics for Food Packaging Industry

This chapter reviews the bioplastics market. Most market reports claim that the bioplastics market is growing. In 2011, bio-based PET had the highest production capacity followed by bio-based PE. Among biodegradable and compostable bioplastics, PLA had the highest production capacity. It is expected that non-biodegradable bioplastics, such as bio-based PE, PP, and PET, will lead the entire bioplastics market over the next 10 years. Braskem, Cereplast, CoCa Cola, NatureWorks, Novamont, PepsiCo, are major key player in current bioplastics market. New technologies for bioplastics production will emerge over the next 10 years.

α-Tocopherol-Loaded Polycaprolactone (PCL) Nanoparticles as a Heat-Activated Oxygen Scavenger

A nanoencapsulation technique was applied to an oxygen-scavenging system, and thermal processing was investigated as an activator to trigger the oxygen-scavenging reaction. α-Tocopherol-loaded polycaprolactone (PCL) nanoparticles (NPs) were prepared using an oil-in-water emulsion solvent evaporation method. The influences of iron(II) chloride, water, and thermal processing on the oxygen-scavenging capability were investigated. NPs without iron(II) chloride, moisture, and thermal processing had no oxygen-scavenging effect. However, the oxygen content (%) in the cup headspace of 20.9% decreased to 20.4% when the oxygen-scavenging system contained NPs, water, and iron(II) chloride. The oxygen content (%) decreased further to 19.5% when water was eliminated from the mixture. In this research, NPs and iron(II) chloride with thermal processing had an oxygen-scavenging capacity of 6.44 cm3 of O2/g and an oxygen-scavenging rate of 0.21 cm3 of O2 g(-1) day(-1). Results indicated that NPs and iron(II) chloride in an oxygen-scavenging system can be used as a heat-activated oxygen scavenger.

Bioplastics for Food Packaging: Chemistry and Physics

There is great potential for using bioplastics in food packaging applications. Reducing carbon dioxide productions as well as biodegradability are major advantages in utilization of bioplastic. However, the production costs for bioplastics from various biomasses still limit the application of bioplastics. Recent developments in bio-based PE, PP, and PET have been successfully introduced to the fields of rigid packaging. They are not biodegradable or compostable, but they have exactly the same physical and functional properties as petroleum-based plastics. Recyclability and low levels of carbon dioxide production are major advantages, as well as their compatibility with existing systems. In addition, bioplastics synthesized from petroleum-based monomers and bio-based monomers such as PBS or PBAT have been actively studied and used in combination with other bioplastics. In the near future, those petroleum-based monomers will be replaced by bio-based monomers.There is great potential for using bioplastics in food packaging applications. Reducing carbon dioxide productions as well as biodegradability are major advantages in utilization of bioplastic. However, the production costs for bioplastics from various biomasses still limit the application of bioplastics. Recent developments in bio-based PE, PP, and PET have been successfully introduced to the fields of rigid packaging. They are not biodegradable or compostable, but they have exactly the same physical and functional properties as petroleum-based plastics. Recyclability and low levels of carbon dioxide production are major advantages, as well as their compatibility with existing systems. In addition, bioplastics synthesized from petroleum-based monomers and bio-based monomers such as PBS or PBAT have been actively studied and used in combination with other bioplastics. In the near future, those petroleum-based monomers will be replaced by bio-based monomers.