Monosaccharides have several hydroxyl groups and a compatible structure with starch polymers resulting in effective plasticization in starch films. Two groups of plasticizers (polyols and monosaccharides) were used to compare their plasticizing efficiency. Fructose, glucose, mannose, galactose, glycerol, sorbitol, ethylene glycol, and maltitol were selected at 13.031 mmol per 100 g of pea starch. Edible starch films were produced after heat gelatinization and dehydration of the 3% starch dispersion. The microstructure, attenuated total reflection foorier transform infrared (ATR‐FTIR) characteristics, thickness, moisture content, tensile strength, modulus of elasticity, elongation‐at‐break, water vapor permeability, and transparency of films were determined. Microstructure of the film solutions showed that some swollen starch granules and their remnants existed in the film. Compared to the FTIR spectra of pure starch films, the spectra of plasticized films showed that more hydrogens bound hydroxyl groups and more water molecules were attracted around starch polymer chains. Ethers were produced in glycerol‐plasticized films. Monosaccharide‐plasticized films were comparable to the polyol‐plasticized films in tensile test, but more resistant in moisture permeation than the polyol‐plasticized films. It was assumed that the structural compatibility of monosaccharides with starch might result in denser polymer‐plasticizer complex, smaller size of free volume, and less segmental motions of starch chains. In conclusion, monosaccharides were identified as effective plasticizers for starch film.

Canola Council of Canada, Winnipeg, Manitoba, Canada The rising costs of nonrenewable feedstocks and environmental concerns with their industrial usage have encouraged the study and development of renewable products, including thermoplastic starch (TPS). Starch is an abundant, plant-based biodegradable material with interesting physicochemical characteristics that can be exploited, and this has received attention for development of TPS products. Starch exhibits usable thermoplastic properties when plasticizers, elevated temperatures, and shear are present. The choice of plasticizer has an effect on TPS, even when these have similar plasticization principles. Most TPS have glass transition temperature, Tg, in the range of approximately -75 to 10°C. Glassy transition of TPS is detected by differential scanning calorimeter (DSC) and thermodynamic analyzer (DMA), although DMA has been found to be more sensitive and effective. TPS has low tensile properties, typically below 6 MPa in tensile strength (TS). The addition of synthetic polymers, nanoclay, and fiber can improve TS and water-resistance ability. The moisture sorption behavior of TPS is described in GAB and BET models, from which monolayer moisture content and specific area are derived. Current studies on surface tension, gas permeability, crystallinity, and so on of the TPS are also reviewed.

AN AN were lower than those of polyol-plasticized starch films, especially at higher plasticizer concentration levels. were lower than those of polyol-plasticized starch films, especially at higher plasticizer concentration levels. were lower than those of polyol-plasticized starch films, especially at higher plasticizer concentration levels. were lower than those of polyol-plasticized starch films, especially at higher plasticizer concentration levels. Except for 4.34 mmol/g of mannose-plasticized film, all the other films showed similar modulus of elasticity at Except for 4.34 mmol/g of mannose-plasticized film, all the other films showed similar modulus of elasticity at Except for 4.34 mmol/g of mannose-plasticized film, all the other films showed similar modulus of elasticity at Except for 4.34 mmol/g of mannose-plasticized film, all the other films showed similar modulus of elasticity at Except for 4.34 mmol/g of mannose-plasticized film, all the other films showed similar modulus of elasticity at the same plasticizer concentration. Polyol-plasticized films had lower T the same plasticizer concentration. Polyol-plasticized films had lower T the same plasticizer concentration. Polyol-plasticized films had lower T the same plasticizer concentration. Polyol-plasticized films had lower T the same plasticizer concentration. Polyol-plasticized films had lower T g

No abstract

No abstract