Polyvinyl alcohol thermoplastic starch

Molasses Paraffin Peat Petroleum pitch Polyvinyl alcohol Potato starch Refined asphalts Resins (natural and synthetic) Rosin Sawdust Seaweed Slack wax Slaughterhouse refuse Straw (pulped) Sucrose Sugars Tanning liquors (tannic acid) Thermoplastic powders Vegetable pulp Water Wheat starch Wood pulp Water... 

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... 

Properties Liquid. Solidification point 71-74C. Formaldehyde condensation products are permanently thermoplastic and water soluble. As increasing amounts of simple urea are mixed with ethanolurea, the condensation products gradually change from pliable film-forming resins into the brittle types. Thus, almost any degree of water solubility and flexibility may be obtained in the final resin. The modified resins formed with ethanolurea are compatible with polyvinyl alcohol, methyl cellulose, cooked starch, and other water-dispersible materials. 

Formulations based on thermoplastic starch, EAA and polyethylene (PE) in different ratio, are suitable for film production. In Table 2.1 a few examples of such compositions (some of them containing also polyvinyl alcohol, PVOH) with their related tensile strength properties are reported. As can be seen, the film obtained with a gelatinized starch level of about 50% shows good tensile properties. 

Ljungberg N, Cavaille J-Y, Heux L (2006) Nanocomposites of isotactic polypropylene reinforced with rod-like cellulose whiskers. Polymer 47 6285-6292 Lu Y, Weng L, Cao X (2005) Biocomposites of plasticized starch reinforced with cellulose crystallites from cottonseed linter. Macromol Biosci 5 1101-1107 Lu J, Wang T, Drzal LT (2008) Preparation and properties of microfibrillated cellulose polyvinyl alcohol composite materials. Compos Part A 39A 738-746 Magalhaes WLE, Cao X, Lucia LA (2009) Cellulose nanocrystals/cellulose core-in-shell nanocomposite assemblies. Langmuir. doi 10.1021Aa901928j Malainine ME, Mahrouz M, Dufresne A (2005) Thermoplastic nanocomposites based on cellulose microfibrils from Opuntiaficus-indica parenchyma cell. Compos Sci Technol 65 1520-1526 Marchessault RH, Sundararajan PR (1983) Cellulose. In Aspinall GO (ed) The polysaccharides. Academic, New York... 

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. 

The combination of starch with a soluble polymer such as polyvinyl alcohol (PVAl) and/or polyalkylene glycols was widely considered since 1970. In the last years the system thermoplastic starch/PVAl has been used for production of starch-based loose fillers as a replacement for expanded polystyrene (Fig. 5). 

The combination of starch with a water soluble polymer such as polyvinyl alcohol (PVOH) and/or polyalkylene glycols has been widely considered since 1970 [150]. Recently, the system, thermoplastic starch/PVOH has been mainly studied for producing starch-based loose fillers as a substitute for expanded polystyrene [151-157]. As an example, Altieri and Lacourse developed a technology based on hydroxy propylated high amylose starch containing small amounts of PVOH for improving foam resiliency and density [151-155]. In this case loose fill was produced directly by a twin screw extruder. More recent patents. Recently more advanced processes and alloys have been developed which have resulted in foams with lower foam densities (8-6 kg/m3) and better performance [158-160]. 

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