Biodegradable polymers from petrochemical

Other compostable polymers from renewable resomces Biodegradable polymers from petrochemical sonrces... 

Biodegradation of biodegradable polymers from petrochemical somces... 

BIODEGRADATION OF BIODEGRADABLE POLYMERS FROM PETROCHEMICAL SOURCES... 

Bionanocomposites Using Biodegradable Polymers from Petrochemical Products... 

Most of the plastics and synthetic polymers that are used worldwide are produced from petrochemicals. Replacing petroleum-based feedstocks with materials derived from renewable resources is an attractive prospect for manufacturers of polymers and plastics, since the production of such polymers does not depend on the limited supply of fossil fuels [16]. Furthermore, synthetic materials are very persistent in the environment long after their intended use, and as a result their total volume in landfills is giving rise to serious waste management problems. In 1992,20% of the volume and 8% of the weight of landfills in the US were plastic materials, while the annual disposal of plastics both in the US and EC has risen to over 10 million tons [17]. Because of the biodegradability of PHAs, they would be mostly composted and as such would be very valuable in reducing the amount of plastic waste. 

PHAs can consist of a diverse set of repeating unit structures and have been studied intensely because the physical properties of these biopolyesters can be similar to petrochemical-derived plastics such as polypropylene (see Table 1). These biologically produced polyesters have already found application as bulk commodity plastics, fishing lines, and for medical use. PHAs have also attracted much attention as biodegradable polymers that can be produced from biorenewable resources. Many excellent reviews on the in vivo or in vitro synthesis of PHAs and their properties and applications exist, underlining the importance of this class of polymers [2, 6, 7, 12, 26-32]. 

While PHB and PHV are not considered true plastics, another biodegradable polymer polycaprolactone (PCL) is a plastic material because its monomer e-caprolactone is obtained on an industrial scale from petrochemical products (cyclohexanone and peroxyacetic acid). This synthetic plastic with its low melting point is easily extrudable and applications in the packaging area are envisioned. 

While biodegradable polymers may be similar to petrochemical-based thermoplastics in terms of their structure, their chemical structure imbues them with technical properties that make them perform in different ways. For example, starch blends can produce film with better moisture barrier protection and higher clarity than some conventional plastics. PLA has a high water vapour transmission rate, which is beneficial for fresh food applications where it is important that the water vapour escapes quickly from the packaging. PLA also reduces fogging on the lid of the packaging. 

Lactic acid is commonly found, which contributes to its wide use in food and food-related industries. It also has the potential for production of biodegradable and biocompatible polymers. These products have been proven to be environmentally friendly alternatives to biodegradable plastics derived from petrochemical materials (Zhang, Jin, and Kelly, 2007). Lactic acid is slightly lipid soluble and diffuses slowly through the cell membrane. As a result of this, the disruption of the cell pH is not its main mode of inhibition (Gravesen et al., 2004). 

Abstract The development and production of biodegradable starch-based materials has attracted more and more attention in recent years due to the depletion in the world s oil resources and the growing interest in easing the environmental burden from petrochemically derived polymers. Furthermore, the unique microstructures of different starches can be used as an outstanding model system to illustrate the conceptual approach to understanding the relationship between the structures and properties in polymers. 

Abstract Succimc add is an important platform chemical derived from petrochemical or bio-based feedstocks and can be transformed into a wide range of chemicals and polymers. Increasing demand for biodegradable poly(butylene succinate) (PBS) will open up a new market for succinic acid. In this chapter, the synthesis of succinic acid is briefly reviewed. We focus on the polymerization, crystalline structure, thermal and mechanical properties, and biodegradability of PBS and its copolymers. PBS shows balanced mechanical properties similar to those of polyethylene and excellent performance during thermal processing. In addition, PBS and its copolymers can biodegrade in various enviromnents, such as soil burial, river, sea, activated... 

PCL -OCH CH CH CH CH CO-ln) is a partially-crystalline polyester that is biodegraded by microbial lipases and esterases. The plastic is made from petrochemical feedstocks. It has too low a melting point (60°C) to be useful in any packaging applications. Higher aliphatic polyesters such as poly(butylene succinate) (PBS) (-0(CH2) OC(CH2)2CO-)n and poly(ethylene succinate) (PES) (-OCCH l OOCCCH l CO-) are also biodegradable at a rate that depends on environmental factors (Kasuya et al., 1997). They have higher melting points of 112-114°C and 103-106°C, respectively, and the properties compare well to those of polyolefins. As succinic acid can be derived from plant sources, the polysuccinates can be potentially a bio-based polymer. 

Synthetic biodegradable polyesters are general made by the pofycondensation method and raw materials are obtained from petrochemical feed stocks. Aliphatic polyesters such as pofy(butylene succinate) and poly( -caprolactone) are cormnercially produced. Besides these ahphatic pofyesters, various types of synthethic biodegradable polymers have been designed [33]. They are, for example, poly(ester amide)s, pofy(ester carbonate)s, pofy(ester urethane)s, etc. Most of them are still at a premature stage. 

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