Functionalization Routes for Keratin from Poultry Industry Side-Streams-Towards Bio-Based Absorbent Polymers

Area of Science:

• Biomaterials Science
• Sustainable Chemistry
• Protein Chemistry

Background:

• Keratin, a protein abundant in poultry feathers, represents a significant industrial side-stream.
• Valorizing keratin from poultry waste offers a sustainable alternative to virgin biomass extraction for biomacromolecules.

Purpose of the Study:

• To evaluate the functionalization of poultry feather keratin using one- versus two-stage processes.
• To assess the impact of two functionalization agents, succinic anhydride (SA) and ethylene dianhydride (EDTAD), on keratin's liquid swelling properties.

Main Methods:

• Keratin functionalization was performed using one-stage and two-stage approaches with SA and EDTAD.
• Liquid swelling capacities for water, saline, and blood were measured for functionalized and non-functionalized keratin.
• Swelling kinetics were modeled to determine water uptake mechanisms and diffusivity.

Main Results:

• Functionalized keratin exhibited significantly enhanced liquid swelling: up to 400% (water), 300% (saline), and 85% (blood) increases.
• The highest overall swelling was achieved with EDTAD in a one-stage process.
• Water uptake followed a two-step process, with EDTAD-functionalized keratin showing higher diffusivity.

Conclusions:

• One-stage functionalization of keratin with EDTAD provides superior liquid absorption performance compared to two-stage methods.
• This approach offers resource savings and environmental benefits, highlighting keratin's potential as a sustainable liquid absorbent material.