Evaluation of UV Curing Properties of Mixture Systems with Differently Sized Monomers

Abstract

Ultraviolet (UV) curing is a photopolymerization technique resulting in a three-dimensional polymer network from monomers and oligomers after exposure to UV light, which is often used for fusion industry. However, shrinkage is an issue that needs to be resolved. Studies of single substances have been extensively conducted, but studies of mixture systems have not sufficiently been undertaken. In this study, we evaluate the shrinkage phenomenon by studying a monomer/monomer binary system and monomer/macromer composite systems. Shrinkage tends to increase when compounds varying in size are used. Similar to the shrinkage phenomenon, the curing rate is also relatively higher in such systems. These synergistic effects are evaluated to be due to the nano-porous effect, and vary with the composition ratio and material structure.

Biomimetic Polymer Surfaces by High Resolution Molding of the Wings of Different Cicadas

“…Directly comparing the feature sizes of the pillars in Table 1 supports this conclusion. Although there were differences between the wing and the secondary mold structure diameters (ME ± 4%, AY ± 25%, TO ± 9%, BTR ± 9%, YTR ± 13%) and also with wing structure heights compared to molded (ME ± 10%, TO ± 9%, BTR ± 1%, YTR ± 13%), the small amount of shrinkage which can happen with UV-curable materials in combination with the natural variation of the wing leads us to believe these are insignificant [ 62 , 63 , 64 ]. The molding method also enabled replica molding of the larger, micron-scale features on the wings, as seen in Supplementary Materials Figure S8 .…”

Facile Microfluidic Fabrication of Biocompatible Hydrogel Microspheres in a Novel Microfluidic Device

“…After curing, the particle volume V 2 represented 80%, 75%, 70%, and 68% of the initial droplet volume V 1 for the dispersed phase with 10 wt%, 20 wt%, 30 wt%, and 40 wt% water, respectively, as compared to 97-99% for the dispersed phase without any water. Shrinkage is inversely proportional to the molecular weight of the monomer units [53], which was not changed here, but it is also inversely proportional to the number of crosslinkable groups per unit volume, which is smaller at a higher water content in the dispersed phase. Therefore, in more dilute solutions, the average distance between prepolymer molecules is greater, and higher-volume contraction occurs during curing.…”

Photocured Nanocellulose Composites: Recent Advances

“…20,23 The basics for photopolymerization reactions is widely discussed in the literature. 17,20,23−25 Photopolymerization made good progress during the last two decades owing to its compatibility with smart and nanomaterials technologies 26 like 3D printing of polymers, novel chemistries, dynamic covalent cross-linking systems, 27 curing of thick parts 28 and composites, 19,29 of photocuring over conventional thermal curing methods are being an ambient room temperature process with very short cycle times (few seconds), high spatiotemporal control of energy input, high solvent resistance of cured films, low volatile organic emissions, low capital investments, low energy intensity, and reduced environmental impact. 30,31 The main drawbacks include limited light penetration depth, nonreversibility and nonrecyclability character of common photopolymers, and toxicity of some material precursors (e.g., photoinitiators fragments) which limit the applications of these materials.…”