Biodegradable films materials

Biodegradable films made from edible biopolymers from renewable sources could become an important factor in reducing the environmental impact of plastic waste. Proteins, lipids, and polysaccharides are the main biopolymers employed to make edible films and coatings. Which of these components are present in different proportions and determine the properties of the material, as a barrier to water vapor, oxygen, carbon dioxide, and lipid transfer in food systems (Gomez-Guillen et al. 2002 and 2009). 

However, PVA is also extensively used in other different forms, such as gel matrices, micro and nano spheres, aerosols, aqueous solution, films, powder etc. Although some of the different types of PVA gels have been referred in chapter 3.3, it still remains much more to say. This clearly proves that PVA is an old, yet new polymer or, in other words, an old polymer with a promising future, due to its capacity to respond to all the actual society priorities clean technologies, non-toxicity, biocompatibility, biodegradability, intelligent materials. 

Chitin, chitosan, and their derivatives offer a wide range of applications including bioconversion for the production of value-added food products, preservation of foods from microbial spoilage, formation of biodegradable films, recovery of waste material from food processing discards, purification of water, and clarification and deacidification of fruit juices (Shahidi et al., 1999) (Table II). 

Poly(3-hydroxybutyrate- o-3-hydroxyvalerate) (PHBV) is a soft, malleable and thermosoftening biodegradable polymer material. It can be easily converted into films, which are applicable for packaging, carry bags, disposable bottles and so on. The hydrophilic backbone chain of the polymer, which contains atoms of oxygen in the polymer chain, accelerates the degradation of bacteria and pathogens. 

Guilbert, S., Gontard, N. 2005. Agro-polymers for edible and biodegradable films Review of agricultural polymeric materials, physical and mechanical characteristics. In Innovations in Food Packaging, Han, J.H. (ed.). Elsevier Academic Press, Oxford, U.K., pp. 263-276. 

In recent ten years, xylans and mannans have been studied as potential raw materials for biodegradable films. Sometimes they are blended with other polymers or mixed with nanoparticles to achieve enhanced properties. This chapter covers the occurrence, structure and properties of xylans and mannans as well as recent smdies on xylan- and mannan-based blends, composites, and nanocomposites. 

An improvement in terms of flexibility for PLA may widen its application as a biodegradable packaging and film material. The addition of plasticizers has been investigated lately in order to improve the fragility and increase the elongation of break or elasticity of PLA. Previous researchers have shown that addition of plasticizers such as polyethylene glycol (PEG), glucosemonoesters and partial fatty acid esters had successfully overcome the brittleness and widen PLA s application [2, 7, 8]. 

Chitin, a waste material from crab and shrimp processing, is poly(N-acetyl-D-glucosamine). The de-acetylated form, chitosan, is primarily used in water purification but is also used as a chemical feedstock. For example, chitosan can be depolymerized to the monomer, which is used as a hair-setting agent in shampoo and hair conditioner. In the future, graft polymers of chitosan may form biodegradable films. Already, carboxymethylated chitin is approved as a food wrap. 

Chiellini E, Solaro R (1996) Biodegradable polymeric materials. Adv Mater 8 305-313 Cyras VP, Commisso MS, Mauri AN et al (2007) Biodegradable double-layer films based on biological resources polyhydroxybutyrate and cellulose. J Appl Polym Sci 106 749-756 De Koning GJM (1993). Prospects of bacterial poly[(R)-3-hydroxyalkanoates]. Center for Polymers and Composites (CPC), Eindhoven University of Technology, Eindhoven Doi Y (1990) Microbial polyesters. Wiley, New York... 

In all materials used in different aspects of cellulose applications in food packaging, the material characteristics including cellulose, plasticizers, etc., and the fabrication procedures like composites, nanocomposites, casting of a film-forming solution, thermoforming, and so on, must be adapted to each specific food product and the conditions in which it will be used such as relative humidity, temperature, etc. Furthermore, edible and biodegradable films must meet a number of specific functional requirements like moisture barrier, gas barrier, water solubility, color and appearance, nontoxicity, etc. 

Novamont, a subsidiary of the Italian company Montedison, marketed Mater-Bi biodegradable film for composting and waste disposal. A typical resin contains 60% starch along with other materials. Mater-Bi resins containing starch and poly- -caprolactone can be handled on conventional film blowing and sealing equipment for LDPE, with minor modifications. One U.S. manufacturer of trash bags made with this material is Biocorp USA, which sells them as... 

A. Anumary, P. Thanikaivelan, M. Ashokkumar, R. Kumar, P.K. Sehgal, B. Chandrasekaran, Synthesis and characterization of hybrid biodegradable films from bovine hide collagen and cellulose derivatives for biomedical applications. Soft Materials 11 (2) (2011) 181-194. 

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