Polyvinyl alcohol, biodegradability

L Chen, SH Imam, SH Gordon, RV Greene. Starch polyvinyl alcohol crosslinked film—Performance and biodegradation. J Environ Polym Degradation 5 111-117, 1997. 

Polyvinyl alcohol is unique in being the only biodegradable carbon-carbon backbone polymer.(35,36) The degradation is oxidative, followed by hydrolytic cleavage, Suzuki claims acids and ketones as metabolites, and Watanabe acids and alcohols. This difference is shown below, schematically. 

Chiellini E, Corti A, Politi B, Solaro R (2000) Adsorption/desorption of polyvinyl alcohol on solid substrates and relevant biodegradation. J Polym Environ 8 67-79... 

Russo M, O Sullivan C et al (2009) The anaerobic degradability of thermoplastic starch Polyvinyl alcohol blends Potential biodegradable food packaging materials. Bioresour Technol 100 1705-1710... 

Chen J, Zhang Y et al (2007) Biodegradation of polyvinyl alcohol by a mixed microbial culture. Enzyme Microb Technol 40 1686-1691... 

Huang MH, Shih YP, Liu SM (2002) Biodegradation of polyvinyl alcohol by Phanerochaete chrysosporium after pretreatment with Eenton s reagent. J Environ Sci Health A Tox Hazard Subst Environ Eng 37 29 1... 

E Matsumura S, Kurita H, Shimokobe H (1993) Anaerobic biodegradability of polyvinyl alcohol. Biotechnoi Lett 15 749-754... 

There is also US research interest in using pectin in polymer applications. Pectin is a complex plant cell wall heteropolysaccharide (based on galactose, rhamnose, arabinose and xylose) that can be blended with synthetic polyvinyl alcohol (PVA) to produce biodegradable polymers with a wider range of properties than those of starch-based polymers alone. The new pectin/PVA biodegradable polymer should be capable of replacing conventional PVA applications in blow-moulded, extruded, film and injection-moulded applications. 

The effect of NaOH on drug release was examined with microspheres prepared with thioridazine and two biodegradable polymers. The wall-forming polymers were poly(DL-lactide) and poly(L-lactide). Sodium oleate was used as the emulsifier, with the exception of one set of experiments where the emulsions were stabilized with polyvinyl alcohol. 

Polyvinyl alcohol is a vinyl polymer with a carbon-carbon backbone similar to other polymers such as polyethylene and polystyrene and is widely used as a water-soluble biodegradable polymer in the manufacture of delivery systems for fertilizers, pesticides and herbicides and is also used to manufacture containers and films. To date, only bacteria have been described as causing biodegradation of polyvinyl alcohols with some causing complete degradation of the polymer (see Shimao, 2001 for review). 

SULFANOLE 334 surfactant is a nonionic biodegradable penetrant and detergent which does not rewet after drying. It may be used in acid or alkaline mediums with minimal effect on its wetting or detergent properties. It is very effective in the removal and suspension of waxes and polyvinyl alcohols during preparation. 

Several other biodegradable, biocompatible, injectable polymers are being investigated for drug delivery systems. They include polyvinyl alcohol, block copolymer of PLA-PEG, polycyanoacrylate, polyanhydrides, cellulose, alginate, collagen, gelatin, albumin, starches, dextrans, hyaluronic acid and its derivatives, and hydroxyapatite. ... 

A biodegradable thermoplastic composition comprising polyvinyl alcohols, polyurethanes or polyacrylates, cellulose fibers, and chitosan is disclosed in U.S. Pat. No. 5,306,550 [125]. 

Another approach to improve the properties of chitosan hydrogels is via the preparation of polymer composites. Porous hydrogels of N-carboxymethyl chitosan/polyvinyl alcohol were prepared by Lee et al. [99]. Hydroxypropyl chitosan was combined with sodium alginate for the formation of biodegradable hydrogels [100]. Chitosan-hyaluronic acid composite was prepared by Tan et al. [101]. 

Polyvinyl alcohol is a synthetic poiymer manufactured hy Air Products, ChrisCraft, Nippon Gohsei, and italway, among others. It is biodegradable once it is dissolved in water. A major limitation to its use is that it is generally not melt processable unless modified. It is also relatively high in cost. 

Polyvinyl alcohol [PVA] is a semi-crystalline water-soluble synthetic polymer made from hydrolysis of polyvinyl acetate. This material is also found to be biodegradable and mineralized in various environments. The degree of solubility and biodegradability as well as other physical attributes can be controlled by varying the MW and the degree of hydrolysis of the polymer [Chauhan, 2012]. 

Qiu, K., and Netravali, A. N. (2012). Bacterial cellulose-based membrane-like biodegradable composites using cross-linked and noncross-linked polyvinyl alcohol. I. Mater.. Sci.. 47,6066-6075. 

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