Plasticizer design strategies enabling advanced applications of cellulose acetate

Plasticized cellulose acetate (CA) is one of the most applied bio-based polymers due to its structural properties and easy processing. Plasticizers are added to CA to increase workability, prevent degradation under processing conditions and ensure thermo-mechanical properties suitable for the intended final application. Moreover, inexpensive and non-toxic solvents enable its processing into fibers, films, and solid blocks. However, when incorporated in the polymer matrix, plasticizers are prone to migration. CA products can suffer embrittlement, cracking, warping, or discoloration during their life cycle, affecting the material's integrity and durability. The design of new plasticizers compatible with the polymer at high concentrations, tailored to be effective in lowering the glass transition temperature, and with a low tendency to migration could considerably reduce material degradation over time. This review offers a perspective on the current plasticizers and comprehensively depicts the plasticization mechanisms in CA for internal and external plasticization. Understanding the plasticization mechanisms paves the way to identify a rationale for designing new plasticizers for this polymer.