Eco-Composites from Silkworm Meal and Polycaprolactone: Effect of Formulation and Processing Conditions

The production of green plastic materials from defatted silkworm meal (SW) through a scalable technique (e.g., injection moulding) would permit the revalorization of a by-product of the textile industry. The textile by-product contains an estimable protein content (similar to 50%) which can justify its applicability in the field of eco-materials. Thus, SW-based materials have been processed and characterized, sometimes requiring the addition of another biodegradable polymer, such as polycaprolactone (PCL), in the formulation. Thermomechanical, tensile and water uptake properties have been assessed at different PCL contents (from 0 to 20%). The viscoelasticity of the plastic composites when heated was greatly affected by the melting point of PCL, which also led generally to an increase in their extensibility and resistance. However, this effect of PCL was diminished when composites were processed at higher moulding temperatures. As PCL possesses a hydrophobic character, a decrease in the water uptake was generally detected as PCL content increased, which could also be related to the lower plasticizer content in the formulation. Silkworm meal is an adequate ingredient to consider in the production of green plastic materials that would eventually add value to a main by-product of the sericulture industry.

Automated summary

The production of green plastic materials using defatted silkworm meal as a raw material has the potential to add value to the by-product of the textile industry. By adding a biodegradable polymer such as polycaprolactone, the performance of the materials can be improved. The study found that the properties of the plastic composites were influenced by the content of polycaprolactone, including their thermomechanical and water uptake properties.