Eco-friendly disposable porous absorbents from gluten proteins through diverse plastic processing techniques

Abstract

The production of biodegradable gluten-based protein foams showing complete natural degradation in the soil after 26 days is here reported as an alternative to commercial foams counterparts in disposal sanitary articles that rely on fossil, non-biodegradable materials. These foams were developed from an extensive evaluation of different foaming methodologies (oven expansion, compression moulding, and extrusion), resulting in low-density foams (ca. 400 kg/m3) with homogenous pore size distributions. The products showed the ability to absorb 3-4 times their weight, reaching relevant ranges for their use as absorbents in single-use disposal sanitary articles. An additional innovative contribution is that these gluten foams were made from natural and non-toxic wheat protein, glycerol, sodium- and ammonium bicarbonate, making them possible as fossil-plastic-free replacements for commercial products without the risk of further micro-plastic and chemical pollution. The impact of different processing conditions on forming the porous bio-polymer network is explained, i.e., temperature, pressure, and extensive shear forces, which were investigated for different chemical processing conditions (pH). The development of future micro-plastic- and chemical-free foams mitigating environmental pollution and waste while using industrial co-products is fundamental for developing large-scale single-use items. An example here is a demonstrated and sustainable sanitary pad prototype. From an industrial perspective, the presented eco-friendly material alternative paves the way for sustainable practices in manufacturing and contributes to the global effort in combating plastic pollution and waste management challenges, Sustainable Development Goals: 12, 13, 14, and 15.