Plasticizer compatibility with amorphous (low-ordered) cellulose and dialcohol cellulose

Abstract

Abstract Biopolymers such as cellulose are promising candidates for replacing fossil-based plastics, but their processing is often limited by their high glass transition temperature ( T g ) and strong intermolecular hydrogen bonding. Plasticizers can improve processability, yet the molecular mechanisms governing their efficiency remain poorly understood. In this work, molecular dynamics (MD) simulations were combined with experimental characterization (DSC, TGA, XRD, FTIR, DMA and NMR) to investigate how different sustainable plasticizers influence the properties of dialcohol cellulose (DALC) and low-ordered cellulose (LOC). Eleven plasticizers were first screened using MD simulations at concentrations of 0–30 wt%, after which four candidates were studied experimentally. Among the tested additives, glycerol and sorbitol showed the strongest plasticizing effects. For DALC containing 30 wt% plasticizer, glycerol reduced T g to approximately − 5 °C, while sorbitol lowered T g to around 25 °C, compared with ≈ 45 °C for systems containing triacetin or ethylene glycol. Simulations revealed that efficient plasticizers form extensive polymer–plasticizer hydrogen bond networks and remain well dispersed in the polymer matrix, whereas ineffective plasticizers show clustering behaviour. Although glycerol produced the largest reduction in T g , sorbitol exhibited much lower diffusivity and higher thermal stability, indicating a reduced tendency for migration and evaporation. These results show that efficient cellulose plasticizers combine strong hydrogen-bonding capability with good miscibility in the polymer matrix. The combined simulation-experimental approach provides molecular insight into plasticizer efficiency and offers a strategy for the rational design of sustainable additives for thermoplastic cellulose materials.