Evaluating the Properties of Native and Modified Milkweed Floss for Applications as a Reinforcing Fiber

The use of natural fibers is a sustainable alternative for developing reinforced-polymer composites. It is believed that the seed flosses of common milkweed, Asclepias Syriraca, may be a promising reinforcing fiber given its uncommon hollow microstructure that is associated with both high specific properties and outstanding insulating capacities. This study presents an overview of the properties of milkweed floss and its potential use in reinforced-polymer composites. Milkweed flosses from Quebec were analyzed to determine their overall dimensions, density, porosity, coefficient of acoustic absorption, thermal conductivity, thermal resistance, and elastic modulus. In parallel, a portion of milkweed fibers was treated with acetone to modify their surface, and the properties of the treated fibers were measured and compared against the characteristics of the original fibers. Infrared spectroscopy was employed to assess differences between the chemical groups on the surface of treated and native fibers. The treatment with acetone removed fatty acids, waxes, and free sugars from the fibers' surface. The acetone treatment did not affect the fibers' microstructure nor their acoustic absorption capacity. The acetone-treated fibers showed greater thermal resistance and a higher thermal conductivity than native milkweed floss. The elastic modulus of milkweed decreased by nearly 49% after the acetone treatment.