Thermoplastic Starch Processing and Characteristics—A Review

Abstract

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.

Effect of Plasticizer Type and Concentration on Tensile, Thermal and Barrier Properties of Biodegradable Films Based on Sugar Palm (Arenga pinnata) Starch

“…Such anti-plasticization phenomena at higher plasticizer concentration are associated with stronger interaction between plasticizer and starch molecules (amylose/amylopectin) that hinders macromolecular mobility [18,75]. According to Zhang et al [82] anti-plasticization of plasticized starch based films occurs when the amount of plasticizer molecules increased above the critical value. Consequently, the interactions between starch polymers become weaker and the cohesive force of the polymer chains is decreased, resulting in a decrease in E% values.…”

“…By definition, Tg is the temperature at which the forces binding the amylose and amylopectin of the starch are relaxed to allow large-scale molecular movements [82]. Hence, Tg of unplasticized and different plasticized SPS films were obtained from the differential scanning calorimetry (DSC) results as shown in Table 1.…”

Effect of plasticizer type and concentration on physical properties of biodegradable films based on sugar palm (arenga pinnata) starch for food packaging

“…Starches are considered as one of the most promising biopolymers due to their biodegradability, renewability, abundant availability and low cost (Imre and Pukánszky 2015;Jiménez et al 2012;Peelman et al 2013;Zhang et al 2014). They are counted as the main carbohydrate resources found in cereal and tuber plants, such as corn and cassava, respectively.…”

Highly functional green materials platform: Starch-ionic liquid-carbon nanotube polymer melt nanocomposites

“…A review has shown that TPS generally has a tensile strength of less than 22 MPa which has limited its applications (Zhang et al, 2014). Generally, the Young's modulus of starch is lower than 50% of the value of PP (polypropylene) or PS (polystyrene).…”

“…Raw starch has an equilibrium moisture percentage of 10%-18% under ambient conditions depending on the species of origin (Zhang et al, 2014). This moisture percentage changes according to the fluctuation of the relative humidity (RH) of the atmosphere where it is stored (Tester et al, 2004).…”