Comparison of composite resins containing UV light-sensitive chitosan derivatives in stereolithography (SLA)-3D printers.

This study produced composite resins by combining acrylate, chitosan (CH), carboxymethyl chitosan (CMCH), hydroxypropyl chitosan (HPCH), and hydroxyethyl chitosan (HECH) to create materials suitable for use in 3D stereolithography (SLA) printers. Tripropylene glycol diacrylate (TPGDA), urethane acrylate (UA), and photoinitiator (Diphenyl (2, 4, 6-trimethylbenzoyl) phosphine oxide (TPO)) were mixed. CH and its derivatives were added separately to the resin to obtain composite resins. The mechanical test results are clear; the optimum TPGDA: UA ratio was 1:1, the cure time was 60 s, and the TPO ratio was 1 %. The optimum viscosity of the resin is 340-350 cP. Hydrophobic/hydrophilic properties of cured composite resins were examined. The addition of CH and its derivatives to the resin caused a decrease in compressive strength. Adding up to 2.5 % CH, CMCH, and HECH to the resin significantly increased the tensile strength of the resin, giving it flexibility. The gel content of cured composite resins was between 97.72 % and 96.11 %. The cured composite resins demonstrated high chemical and solvent resistance to HCl, NaOH, and HF but exhibited limited resistance to toluene and chloroform. The accelerated UV aging test results show that adding CH derivatives to the resin makes the composite resin more prone to photooxidative aging.