Fig. 4: Circular DLP printing of EtLp1–GlyLp3 (31:69 wt%) resin.
From: A renewably sourced, circular photopolymer resin for additive manufacturing
a, 1H NMR spectroscopic analysis of pristine resin (300 MHz, 300 K, CDCl3) compared to recycled resins (400 MHz, 298 K, CDCl3). b, SEC images of pristine resin compared to recycled resins (CHCl3 + 0.5% v/v NEt3, against polystyrene standards). c, Photorheology at ambient temperature of pristine resin compared to recycled resins under oscillatory shear (0.2 Hz with an amplitude of 25% for 50 s) without irradiation, then the sample was irradiated after 50 s. d, Z depth cure screening of pristine compared to recycled resins by irradiating a 2D-square and measuring sample thickness (z axis depth) versus irradiation time (5–60 s). e, x–y printing accuracy for pristine resins compared to recycled resins determined by comparing surface area of squares to theoretical square size (pixel size 30 µm). Theoretical surface area of each square and number of squares (sample size): 4 mm2 (n = 3); 1 mm2 (n = 4); 0.25 mm2 (n = 5); 0.0625 mm2 (n = 6). Centre value is average surface area and error bars indicate 1 standard deviation. f, 3D-printed parts of ‘3DBenchy’ for pristine resin compared to recycled resins. A photoinitiator was added to recycled resins (1.5 wt% for the first recycle; 2.5 wt% for the second recycle) for photorheology and printing.
