Reinforcement of Stereolithographic Resins for Rapid Prototyping with Cellulose Nanocrystals

TLDR: Through the fabrication of 3-dimensional parts, it was shown that the CNC-filled resins can be processed with standard equipment in a stereolithographic process that is widely used for rapid prototyping and rapid manufacturing.

Abstract: We report on the mechanical properties of optically curable stereolithographic resins (SLRs) which were reinforced through the addition of small amounts of cellulose nanocrystals (CNCs). The resin/filler mixtures are readily accessible via simple mixing processes. A detailed rheological investigation of such mixtures and the successful processing of these materials on a commercial SLR machine show that at low filler concentrations (below 5%) the processability of the materials is barely impacted. The storage modulus, E′, increased steadily with increasing CNC content in the regimes below and above the glass transition. A remarkable modulus enhancement was observed in the rubbery regime, where E′ increased by 166, 233, and 587% for CNC/SLR nanocomposites with 0.5, 1.0, and 5.0% w/w CNC, respectively. The modulus increase was less pronounced in the glassy state, where E′ increased by 21, 32 and 57%, for the same compositions. The increase in tensile strength was of similar magnitude. In comparison to previo...