Biodegradable polymers polyvinyl alcohol

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... 

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). 

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. ... 

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 [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]. 

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

With respect to sustainability and waste management, the implementation of human-made, biodegradable polymers in textile coating is also examined. Palanikkumaran et al. (2008) developed waterproof breathable coatings based on polyvinyl alcohol for cotton fabrics. 

Polyvinyl alcohol was soon abandoned due to excessive ruptures. Polyamide and polyacrylonitrile were discovered to be biodegradable, although it took 12 to 24 months to occur. Thus polyethylene terephthalate (polyester) and polytetrafluorethylene (PTFE) became the polymers of choice. Both these materials have demonstrated their longevity as an implant. ... 

Polycarboxylates Carboxylate derivatives of poly(vinyl alcohol) are biodegradable and functional in detergents as co-builders, although too costly to be practical replacements for polyacrylic acid at this time. Matsumura et al. polymerized vinyloxyacetic acid [69, 70] and Lever has patented polymers based on vinyl carbamates obtained from the reaction of vinyl chloroformates and amino acids such as aspartic and glutamic acids [71]. Both hydrolyze (Scheme 4), to polyvinyl alcohol, which is biodegradable. 

Figure 2. Chemical structures of some biodegradable polymer materials PVOH polyvinyl alcohol,...

Polyvinyl alcohol is a biodegradable polymer obtained by partial or complete hydrolysis of polyvinyl acetate (PVA, of petrochemical origin) to remove acetate groups (Figure 2). The... 

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