Packaging petroleum-based

Biotec s product portfolio includes thermoplastic starch, which can be substituted for petrochemical based plastic packaging. Stanelco s radio frequency sealing technology can be used to process starch polymers without the degradation caused by other methods such as thermal processing. The purchase of Biotec will help the company develop alternatives to petroleum-based packaging. 

In 2005, Wal-Mart decided to switch from petroleum-based plastics to corn-based plastics based on NatureWorks PLA. NatureWorks will initially supply PLA for manufacture of 114 million packages a year for fresh strawberries, sprouts, cut fruit and herbs to Wal-Mart. Plastic gift cards, salad boxes, deli trays, tomato packages, plastic film on donut boxes, and other applications will follow. 

Biodegradable biopolymers (BDP) are an alternative to petroleum-based polymers (traditional plastics). It will be important to find durable plastic substitutes, especially in short-term packaging and disposable applications. The continuously growing public concern concerning this problem has stimulated research interest in biodegradable polymers as alternatives to conventional non-degradable polymers such as polyethylene and polystyrene, etc. The economic value of renewable raw materials will increase to a significant extent [1] and induce new industrial activities [2,3]. 

Polylactic acid is likely to have significant future potential in a variety of applications due to specific advantages compared with conventional petroleum-based polymers. The cost-performance balance of PLA has resulted in its use in many applications, including packaging, fibers, and medicals. The use of PLA as an alternative to petroleum-based polymers will increase demand for agricultural products such as corn and sugar beets, and is an advanced example of sustainable technology. 

Natural polymers such as starch and protein are potential alternatives to petroleum-based polymers for a number of applications. Unfortunately, their high solubility in water limit their use for water sensitive applications. To solve this problem thermoplastic starches have been laminated using water-resistant, biodegradable polymers. For example, polylactic acid and P(3HB-co-3HV) were utilised as the outer layers of the stratified polyester/PWS (plasticized wheat starch)/polyester film strucmre in order to improve the mechanical properties and water resistance of PWS which made it useful for food packaging and disposable articles [65]. Moreover, improved physic-chemical interactions between P(3HB-CO-3HV) and wheat straw fibres were achieved with high temperature treatment. It resulted in increased P(3HB-co-3HV) crystallization, increased Young s moduli and lowered values of stress and strain to break than the neat matrix of P(3HB-co-3HV). There was no difference in the biodegradation rate of the polymer [66]. 

PLA suffers from its cost and also some weaknesses in thermo-mechanical properties (mainly heat resistance) however, it is considered as one of the most promising bioplastics for the substitution of the petroleum-based polymers in materials and packaging applications.The main industrial PLA companies are Nature Works, invested by Cargill and PTT Global Chemicals, with the announced production of 140 000 metric tons of PLA per year as well as the traditional lactic acid producers such as Purac through Synbra and the collaboration with Sulzer Chemtec and Galactic through its joint venture with Total, Futerro (1500 tons per year). 

Polylactides (PLA) may have many potential applications for an important set of products but some of their properties should be improved to obtain similar performance to petroleum-based commodities. One of the most important current applications of PLA is food packaging, in particular for short-shelf-life products with common applications such as rigid containers, drinking cups, over-wrap and lamination films. PLA production and consumption are expected to increase therefore research into the variation of PLA mechanical and barrier properties is currently very active. The control of barrier properties in PLA films is possible by modification of the polymer network through the formation of intramolecular and inter-molecular covalent crosslinking, for example by applying thermal treatment, or by modifying the chemical composition. Another method is to incorporate fillers, in particular layered nanoclays, and this will be the subject of this chapter. 

Unlike petroleum-based polymers, PHAs are broken down in the environment and the rate of degradation is influenced by factors such as pH, moisture, temperature, the molecular weight of both the individual s monomer units and the chain lengths as well as crystallinity and the absence or presence of antimicrobials within the PHA. The degradation of PHA packaging is considered to be the natural consumption of the polymer by biological microorganisms to produce CO2 and H2O. 

As discussed above, PLAs have physical properties useful in fibers, packaging, and other applications traditionally dominated by petroleum-based resins. Although the general literature on polylactides is extensive, only a few... 

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