Plastics petroleum-based

Human society has benefited tremendously from the use of petroleum-based plastics due to their versatility and ease of manufacturability ... 

Polylactic acid (PLA) is a biodegradable polymer derived from lactic acid. It is a highly versatile material and is made from 100% renewable resources like corn, sugar beet, wheat and other starch-rich products. Polylactic acid exhibits many properties that are equivalent to or better than many petroleum-based plastics, which makes it suitable for a variety of applications. 

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. 

Japanese electronics company Sharp has developed technology to blend PLA biopolymers with conventional plastics recovered from scrapped consumer appliances. Petroleum-based plastics are generally incompatible with bioplastics, and blends tend to show inferior properties such as impact strength and heat resistance. Sharp claims to have overcome these problems with a microdispersion technology that dramatically improves the properties of the blended material. The company expects to use such blends in its consumer electronics products by early 2007. 

NatureWorks PLA can be extruded, cast or biaxially oriented, and thermoformed using conventional processing equipment. The company claims that NatureWorks PLA performs like traditional petroleum-based plastics, and in some cases offers better performance characteristics, including gloss, clarity, strength, and flavour and aroma barrier. 

Arthur Blank introduced CornCard USA, a corn-based plastic card based on NatureWorks PLA as an alternative to traditional petroleum-based plastic cards. CornCard USA is identical to traditional plastic cards in look, feel, and durability while offering the same reliability and functionality. Major national retailers and quick service restaurants are already considering alternatives to traditional petroleum-based plastics. 

Table 5.2 Sustainability improvements of bio-based plastics relative to petroleum-based plastics (PBP) (Rosalia et al., 2012)...

Abstract Biopolymers are expected to be an alternative for conventional plastics due to the limited resources and soaring petroleum price which will restrict the use of petroleum based plastics in the near future. PLA has attracted the attention of polymer scientist recently as a potential biopolymer to substitute the conventional petroleum based plastics. The chapter aims to highlight on the recent developments in preparation and characterization of PLA blends (biodegradable and non-biodegradable blends), PLA composites (natural fiber and mineral fillers) and PLA nanocomposites (PLA/montmorillonite, PLA/carbon nanotubes and PLA/cellulose nano whiskers). 

Despite its origin form the nature, PLA s good stiffness and strength has enabled it to compete with other existing chemically based commodity plastics. Previous study on the mechanical properties of neat PLA by Jacobsen et al. [1] showed that PLA has great potential to be a substitute polymer for petroleum based plastics. The respective values of mechanical properties of PLA [2] with comparison of other petroleum based plastics e.g. polypropylene (PP) [3], polystyrene (PS) [4], high density polyethylene (HOPE) [5], polyamide (PA6) [6] shown in Fig. 11.2. 

Thus, the development of PLA/LLDPE nanocomposites with the correct addition of LLDPE and MMT would engineer a material with targeted and optimal performance for any specific requirements of different applications. Thus, it s inflicted that the optimum toughened PLA nanocomposites formulation hold the future as potential replacement for petroleum based plastics in the near future. 

Based upon their mechanical and processing properties, many natural and renewable polymers are quite suitable to replace petroleum- based plastics in specific applications where an extended life span of plastic product is not desirable. Furthermore, consumers acceptance of such bio-based plastics is expected even if natural polymer price represents a limitation on the cost of the final products. Materials such as commodity crops, agricultural waste and/or by-products are a good source of natural and renewable polymers and are comparatively less expensive. Agro-fibers, which represents a considerable portion of such natural materials is available on a worldwide basis and are being used in a variety of tq>plications. In some applications, fibrous materials have been blended with thermoplastic mauix to develop composites containing various percentages of the fibers ... 

Preparation of petroleum-based plastics utilizes toxic and noxious chemicals. 

Solid waste of non-degradable petroleum-based plastics, and the toxic and hazardous... 

Global environmental concerns have resulted in ever-mounting costs for disposal of solid waste. A particularly troubling solid waste is nondegradable petroleum-based plastics, and... 

PHA are envisioned to be one of the most promising and futuristic materials which will be beneficial to mankind and the world. Current world trends are focused on sustainable development from renewable and eco friendly resources hence, PHA have garnered growing attention as an alternative to petroleum based plastics. 

Generally speaking, bio-based plastics include starch-based plastics, protein (soybean protein) based plastics, and cellulose-blended plastics. They can also be blended with conventional plastics such as polyethylene (PE), polypropylene (PP), and poly(vinyl alcohol). However, such bio-based plastics are only partially biodegradable. The residual petroleum-based plastics remain as broken pieces, creating additional pollution. In addition, these plastics have intrinsic thermal and mechanical weaknesses, and they are now discouraged for applications. 

Although these plastics are bio-based, their properties are very similar to those of traditional petroleum-based plastics. Like PE based on bioethanol (leading to bioethylene), they are exactly the same as petroleum-based PE (Table 1)... 

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