Polyvinyl alcohol -starch blends

In the homogenous mixture of Starch and Polyvinyl alcohol (PVA), 30 % of plasticizer was mixed to make Pure blend. Then 10 % cellulose was mixed into above mixture followed by removal of extra water gave Cellulose-Reinforced starch-PVA blends. The different proportions of Fly ash were mixed into mixture of Cellulose-Reinforced starch-PVA blends to get various fly ash inserted Cellulose-Reinforced starch-PVA blends. Solubility, swelling behaviour and water absorption studies of Fly ash blends were measured at different time intervals at relative humidity of 50-55%. The insertion of Cellulose into starch-PVA blend decreases the solubility of blends due to the hydrophobicity of cellulose, but the solubility further increases by insertion of Fly ash into starch-PVA matrix that indicating the mechanical stability enhancement of blends. The water absorption behaviour of fly ash blends increases rapidly upto 150 min and then no change. The optimum concentration of Fly ash into Cellulose-Reinforced starch-PVA blend was 4%. 

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... 

Superabsorbent polymers are now commonly made from the polymerization of acrylic acid blended with sodium hydroxide in the presence of an initiator to form a polyacrylic acid, sodium salt (sometimes referred to as cross-linked sodium polyacrylate). Some of the polymers include polyacrylamide copolymer, ethylene maleic anhydride copolymer, cross-linked carboxy-methyl-cellulose, polyvinyl alcohol copolymers, cross-linked polyethylene oxide, and starch grafted copolymer of polyacrylonitrile to name a few. The latter is one of the oldest SAP forms created. 

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. 

Exhibits high adhesion to synthetic fibres and is particularly recommended for use on continuous filamant acetate. In conjunction with starch, SCMC or polyvinyl alcohol it is an excellent adhesion promoter for the sizing of staple synthetic fibres and their blends with cellulosics. 

In this regard, polyvinyl alcohol (PVA), a hydrolysis product of polyvinyl acetate, is well suited for blending with natural polymers since it is highly polar and water-soluble synthetic polymer which is also biodegra ble. PVA and starch films have been prepared for use as agricultural mulch films and as water-soluble laundry bags. Cast films made firom PVA and cellulose, prepared in N,N-dimethylacetamide-lithium chloride, exhibited good miscibility due to their mutual ability to form infra-... 

Sreedhar, B., Chattopadhyay, D.K., Karunakar, M.S.H., and Sastry, A.R.K. 2006. Thermal and surface characterization of plasticized starch polyvinyl alcohol blends crosslinked with epichlorohydrin. J. Appl. Polym. Sci. 101 25-34. 

The main component of warp size is usually starch, polyvinyl alcohol (PVOH) or a blend of the two. Other size materials are sometimes used commercially to a lesser extent. These other, less often used types, include derivatized natural sizes and synthetic sizes listed in Table 7.12. In addition to the main size components... 

Large amounts of adhesive mixtures, mainly based on potato or com (maize) starch (with plant varieties grown specifically for the purpose), are employed in paper coating, where the adhesive provides a bond between the fibrous (wood-pulp based) stmcture of the paper and the white china-clay-based surface layer, which can be printed. To improve performance in printing processes, these surface layers are often blended with wood rosin-based products and with polyvinyl alcohol of synthetic origin. Polyvinyl alcohol in adhesives (and its precursor polyvinyl acetate) can be made from ethanol obtained by the fermentation of starch - and once were so made - but the processes, carried out in dilute aqueous solution, are immensely wasteful of thermal energy. 

The complex formed by amylose with the complexing agent is usually crystalline, characterized by an amylose single helix around the complexing pol3mer [32]. Amylopectin does not interact with the complexing polymer, remaining in the amorphous phase. Starch can also be blended with polyvinyl alcohol (PVOH), for the production of foamed products, such as trays for food. Starch esters reinforced with natural fibers exhibit properties similar to those of polystyrene (PS). 

Thermoplastic pehuen starch (TPS) and TPS/poly (lactic acid) (PLA)/polyvinyl alcohol (PVA) composites, reinforced with 5 and 10 % of pehuen husk, were prepared by melt blending (Castano et al. 2012). Before melt blending, the respective components of the samples were premixed by hand at room temperature. TPS composites were blended at 120 °C with a rotor speed of 60 rpm for 15 min. TPS/PLA/PVA blend and TPS/PLA/PVA composite were mixed at 160 °C and 40 rpm for 15 min and finally, the composites were injection molded to obtain the films. 

Tang, X. and Alavi, S. (2011) Recent advances in starch, polyvinyl alcohol based polymer blends, nanocomposites and their biodegradabilily. Carbohydr. Polym.,... 

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