Petroleum-derived biodegradable polymers

Biodegradable polymers are polymers that imdergo microbially induced chain scission leading to mineralization. Biodegradable polymers may not been produced from bio-source only, but it can be derived from the petroleum source (Ray and Bousmina, 2005). Efforts... 

Despite the highly versatile application prohles of polymers with adjunct sucrose (or other sugar) residues—their major asset is enhanced hydrophUicity as compared to their hydrophobic petroleum-derived counterparts—interest appears to be restricted to biomedical uses. Currently none is produced commercially, as the generation of vinyl-sucroses and their often capricious polymerization have made their use as commodity plastics uneconomical. Another reason is their limited biodegradability only the sugar portion is biodegradable, with a polymeric carbon chain left over. Because biodegradability is a major issue today, " these polyvinylsaccharides are unlikely to become petrochemical substitution options in the near future. 

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. 

The over growing environmental pressure caused by the wide spread consumption of petroleum based polymers and plastics has hastened the development of biodegradable and environmentally acceptable materials. Biopolymers derived from various natural resources such as proteins, cellulosics, starch and other polysaccharides are regarded as the alternate materials. Biodegradable polymeric materials derived from renewable sources are the most promising materials because of their easy availability and cost effectiveness. Biodegradable modified polysaccharides have been found to possess varied applications such as salt resistant absorption of water [109]. 

Biodegradable polymers The most convenient method that has emerged in this regard is the usage of biodegradable polymers and their derivatives. As a result, synthesis and modification of renewable resource-based eco-friendly materials as substitutes for the existing petroleum-based resources have been a major subject of research in recent years. Some... 

BIODEGRADABLE POLYMERS FROM PETROLEUM-DERIVED PRODUCTS... 

Development of solvent free, 100% solid adhesives Development of safer cross-linking systems for 100% solid adhesives Replacement of petroleum-derived polymers with bio-based alternatives. Examples include polylactic acid, polyhydroxyaUcanoates, elastin, and soy protein derivatives (biodegradable)... 

There are currently biodegradable polymers with characteristics and properties very similar to those from conventional polymers derived from petroleum (Tables 1 and 2). 

Recently, the possibility of replacing petroleum-derived synthetic polymers with natural, abundant and low-cost biodegradable products has gained much interest in both academic and industrial fields. " For instance, the production of plastics in Europe reached 57 million tons in 2012, mostly divided between polyethylene, polypropylene, poly(vinyl chloride), polystyrene and poly(ethylene terephthalate) production. These fossil-based plastics were consumed and discarded into the environment, generating 10.4 million tons of plastic waste, most of which ended up in landfills (Figure 1). 

Bionanocomposites are an ecological alternative to conventional nanocomposites based on petroleum-derived polymers, as they are based on biodegradable polymers obtained from renewable resources. Biomass is the source of agropolymers like starch and cellulose and also of monomers used to chemically synthesize polymers like polylactic acid (PLA). Other kinds of biopolymers, e.g., xanthan gum and poly (hydroxyalkanoates), are produced by microorganisms. Even though most of the bionanocomposites reported in the hterature are based on layered sihcates, the number of examples illustrating the use of fibrous clays in the preparation of new bionanocomposites is growing rapidly. 

The naturally biodegradable polymers such as starch, chitosan and cellulose derived from natural sources have produced a number of interesting NR blends and IPNs. These blended systems have an advantage in that they create fewer waste disposal problems compared to the petroleum based polymeric materials. The use of stareh blends to enhance the biodegradability of conventional plastics has been reported by many researchers in order to reduce the environmental impaet of petroleum based plastic products and waste. The NR/maize stareh blends exhibited a decrease in their mechanical strength due to the speeifie properties of starch. However, the blended polymers showed a low interfaeial interaetion between the two phases due to the different polarity behaviour of the hydrophobic NR and the hydrophilic starch. 

Polylactic acid, or polylactide, more commonly known as PLA, is a biodegradable polymer derived from 100% renewable resources. PLA, conq>arable to petroleum based plastic, is now used in a variety of industries including packaging, clothing, medicine and more. Classified as GRAS (generally recognized as safe) by FDA, PLA is a nonvolatile and odorless polymer [56 - 59]. 

---