Photopatterning of Thiol-ene-Acrylate Copolymers

Thiol–Ene Based Polymers as Versatile Materials for Microfluidic Devices for Life Sciences Applications

“…However, this can be circumvented, when thicker layers (>100 μm) are desirable, by using spacers. In that case, a photomask is placed in direct contact with the prepolymer and a spacer in-between the (polymer) mask and the substrate defines the layer thickness. ,,− , Using the latter method, the best feature quality and an aspect ratio of up to 13 can be obtained using a minimal concentration of the photoinitiator and an initiator to inhibitor ratio of 1:1 . Interestingly, off-stoichiometric formulations improve the quality of photostructured features; the underlying reasons are elaborated in ref .…”

Synthesis and Properties of Networks Based on Thiol‐ene Chemistry Using a CO2‐Based δ‐Lactone

“…The reaction has advantages like fast kinetics, high conversion, good selectivity, and lack of byproduct . Diverse polymers have been synthesized based on thiol‐ene click reaction, such as shape‐memory materials, photopatterned surfaces, and films . Its step‐growth nature when initiated by radicals makes it very suitable to make highly uniform networks.…”

Tough Semicrystalline Thiol–Ene Photopolymers Incorporating Spiroacetal Alkenes

“…All polymers contained an equivalent amount of thiol and −ene functional groups to maximize polymerization efficiency and were made following a previously described protocol. 11 In brief, we mixed liquid monomers with photoinitiator in a clean glass vial and warmed the mixture to 75 °C in an oven to melt the crystalline DVTU, which has a melting temperature of approximately 45 °C. We cast the monomer mixture between parallel glass slides separated by 1 mm thick rubber spacers and held in place by clips.…”

“…Belonging to this category, thiol–ene polymerization is desirable for its fast reaction kinetics, homogeneous network formation, and ability to control polymer backbone chemistry, functionality, and cross-link density . In recent years, several groups have used thiol–ene click reactions to synthesize materials for a wide variety of applications, including low-shrinkage dental fillings, , shape-memory materials, neurological probes, , photopatterned surfaces, microfluidic devices, − films and coatings, , and optical networks that exhibit liquid crystalline behavior. ,− However, despite its many advantages, several limitations have been noted, including poor thermomechanical properties caused by flexible and nonpolar thioether linkages, strong odor of small thiol molecules, and a limited library of affordable and commercially available thiol monomers. , …”

“…As a result, much research has focused on incorporating different alkene moieties such as (meth)­acrylates, , urethanes, − and norbornenes along the polymer backbone to achieve desired material properties such as stiffness, elongation, and strength. ,,, Tough thiol–enes have proven particularly elusive; the vast majority of thiol–ene polymers suffer from both low failure strain, caused by large amounts of cross-linking, and anemic stress–strain behavior due to a lack of energy dissipation present in the network. The toughest reported thiol–ene photopolymers have been thiourethanes and thiol–isocyanates, ,, which harness a large amount of interchain hydrogen bonding to dissipate energy under deformation and improve mechanical performance, especially when polymerized into thermoplastics or elastomers that enable large deformation.…”