Properties Of Starch Foams Research Articles

Performances of starch foam improved by an alginate coating

This research aims to develop an environmentally friendly food packaging based on starch foam coated with alginate. The foam was coated with various concentrations of an alginate solution (0, 0.5, 1.0, 1.5, and 2.0 %w/v). The effects of these coatings on the properties of starch foam were then investigated. The results showed that the alginate coating increased the density of the starch foam. Starch foam coated with the alginate solution at a concentration of 1.0 %w/v showed the optimum flexural stress at maximum load (4.72 MPa), hardness (96), and mass loss in water (5.51 %). These results showed significant improvements in these properties by comparison with the uncoated foam. The alginate coating slightly improved the thermal stability of the starch foam and did not significantly delay the biodegradation of the starch foam in soil. In conclusion, coating starch foam with an alginate solution presents a viable approach to developing sustainable food packaging materials with enhanced mechanical and water resistance properties.

Enhanced properties of starch based foams with modified starch/polyester blend as masterbatch

AbstractStarch/PBAT blends were reactively extruded as masterbatch with the addition of tartaric acid (TA) and epoxide chain extender ADR4468 (ADR). The effects of tartaric acid and chain extender on the mechanical properties and structure of starch/PBAT blends were evaluated. The tensile strength of starch/PBAT blends with TA and TA/ADR increased by 31.4% and 85.6%, respectively. Further, starch, plasticizer, and blowing agent were melt extruded with this blend masterbatch, and the effects of masterbatch on the foamability, morphology, and properties of starch foams were investigated. When the masterbatch content was 10 phr, the obtained foam had the lowest apparent density (445.1 kg m−3), and the compressive strength, recovery, and water resistance of the foam were also improved significantly.

Preparation of rubber seed shell powder by planetary ball milling and its influence on the properties of starch foam

Starch foam composites containing rubber seed shell particles of different sizes were prepared and characterized. The first objective was to prepare small particles of rubber seed shell using a planetary ball mill at different rotational speeds (300 and 600 rpm) and milling times (20, 40 and 60 min) to optimize the milling condition to achieve the smallest possible particle size. The second objective was to study the influence of the size of the rubber seed shell particles on the properties of the starch foam. Laser particle size analysis and morphological observation by scanning electron microscope (SEM) revealed the optimal milling condition to be 600 rpm for 40 min. The smallest average particle size obtained at this condition was 51.57 μm. Starch foam containing the smallest particles (GRS) exhibited greater flexural stress at maximum load and narrower cell size distribution and had a lower density than starch foam composite with crude rubber seed shell (CRS) at the same filler content. The small size and high surface area of GRS enabled a better dispersion of filler particles and the establishment of stronger interactions within the starch matrix. The change in the color parameters and whiteness values of the rubber seed shell particles can be attributed to exposure to the heat generated by ball milling and the reduction of the average particle size. The effect of the addition of GRS and CRS on the thermal properties of the composites was determined by simultaneous thermogravimetry – differential scanning calorimetry.

Preparation and characterization of kaolin/starch foam

The objective of this work was to study the effect of the kaolin content on the properties of starch foams. The kaolin/starch foams were made with kaolin contents that ranged from 0 to 15m% by baking in a hot mold. The starch and kaolin/starch foams were stored at room temperature with a relative humidity (RH) of 55% for 7days prior to testing. An increase in the kaolin content increased the foam density. The izod impact strength increased up to 1151.37J/m2 at the highest kaolin content (15m%). The improvement was about five times the izod impact strength of pure starch foam. Moreover, the presence of any kaolin reduced the water absorption ability of the starch foam. Scanning electron microscopy revealed that kaolin increased the size of the starch foam cells and was itself well dispersed. Kaolin/starch foams showed a higher thermal stability than pure starch foam.