Functional Properties of Polylactic Acid Starch‐Based Loose‐Fill Packaging Foams

Abstract

In this study, attempts were made to improve the characteristics of starch‐based plastic foams by blending starch with polylactic acid (PLA), a biodegradable polymer made from renewable sources. Formulations of the foams (types of starch, ratio of starch to polymer, and moisture content) were optimized. Physical and mechanical properties of the foams, including expansion, unit density, bulk density, water solubility index (WSI), spring index, and compressibility on both single piece and bulk samples were determined. The addition of the PLA polymer to regular (25% amylose) and waxy corn starches significantly improved the physical and mechanical properties of the extruded foams. Foams made from waxy starch had better radial expansions, higher WSI, higher compressibilities, and lower spring indices than those of regular starch foams. Both regular and waxy starches produced foams with similar unit and bulk densities, bulk compressibilities, and bulk spring indices. Increasing PLA polymer contents increased the radial expansions and spring indices and significantly reduced the unit and bulk densities and bulk compressibilities. Changing the PLA content had no significant effect on WSI, compressibilities, and bulk spring indices. Increasing the moisture content adversely affected foam characteristics. The formulation containing waxy starch, 40% PLA, and 19% moisture produced a loose fill foam with the best physical characteristics and mechanical properties.

Preparation and characterization of tapioca starch‐poly(lactic acid)‐Cloisite NA+ nanocomposite foams

“…A cylindrical aluminum container with a volume of 365 cm 3 (6.93 cm in diameter and 9.68 cm in depth) was used to confine the bulk samples. [24] The forces required to initially compress the samples to 80% of their original volumes and the forces required to recompress the same samples 1 min after releasing the initial load were recorded. BSI was calculated by dividing the recompression force by the initial compression force and has an ideal value of 1.…”

“…It was calculated by dividing the peak force required to compress (deform) the sample by 80% [to 20% of their original dimension (diameter)] by the initial axial cross-sectional area of the foams. [24] A mean value was obtained by averaging five replicates.…”

Physico-chemical and Mechanical Properties of Cornstarch-poly(Lactic Acid) Extrudates as Affected by Ceric Ammonium Nitrate

“…Fang et al . 2) also reported that the addition of PLA improved the physical and mechanical properties of starch based foams. Ke et al .…”

“…Fang et al . 2) reported the unit density of the extrudates with 40% PLA was about 40 kg m 3 . An addition of 0.25% CAN and 25% PLA gave a bulk density similar to that of 40% PLA without CAN.…”

Synthesis and Characterization of Novel Water Soluble Starch Tartarate Nanoparticles

“…Starch has been traditionally being widely used as a major low-cost food item in many countries. Due to its low-toxicity, abundant availability, biodegradable, and low cost, starch and its derivatives are widely used in various industry applications such as coating and sizing in paper industries, binder and adhesives, absorbent, drug delivery carriers, and implants [3][4][5][6]. However, the inherent poor mechanical properties, insolubility in water, and high viscosity have limited the utilization of native starch in various applications.…”