Increasing interest in competitive, sustainable, and biodegradable alternatives to petroleum‐based plastics has encouraged the developmentof protein‐based plastics. The formation of a homogeneous protein melt during extrusion occurs through: denaturation, dissociation, unraveling, and alignment of polymer chains. The presence of covalent cross‐links is unfavorable, decreasing chain mobility, increasing viscosity and preventing homogenization. Proteins have high softening temperatures, often above their decomposition temperatures. To avoid degradation, the required chain mobility is achieved by plasticizers. By understanding a protein's physiochemical nature, additives can be selected that lead to a bioplastic with good processability. The final structural and functional properties are highly dependent on the protein and processing conditions. magnified image

Plasma surface modification of polymers is a well‐established method applied to increase the surface energy of these materials, where the capacity of cold plasmas to generate free radicals and functionalize the surface with polar groups is widely reported in the literature. This article provides a comprehensive literature review on plasma surface treatment, plasma‐induced grafting, and plasma polymerization, evaluating how these techniques can be applied to modify the bulk properties of polymers. A novel process of plasma‐induced polymer bulk functionalization in the melt state is introduced, where an atmospheric pressure plasma jet could be applied to a continuous reactive extrusion process, enhancing the production of graft copolymers for compatibilization of polymeric blends and fiber composites.