Synthesis of aliphatic polymers with high refractive index by photoinduced polyaddition of thiols to bifunctional allyl monomer containing tetrathiaspiro structure

Abstract

Zinc chloride effectively catalyzed the reaction of allyl‐substituted episulfide and cyclic trithiocarbonate to obtain the corresponding bisallyl monomer containing tetrathiaspiro ring in high yield. The homogeneous mixture of the bisallyl monomer, multifunctional thiols, and a catalytic amount of photo‐radical initiator undergoes a photoinduced thiol–ene reaction to result in cross‐linked films. Thus the films obtained in this way, although they are aliphatic polymers containing neither aromatic ring nor halogen atom, have a high refractive index (nD25) of around 1.63.

Highly Transparent Benzothiazole-Based Block and Random Copolymers with High Refractive Indices by RAFT Polymerization

“…We also demonstrated their nanoimprinting based on thiol–ene click chemistry, in which a flexible alkyl chain is incorporated into the main chain to achieve good processability for UV nanoimprinting lithography . In the same way, various nonconjugated polymers with flexible main chains and sulfur-containing units have been used to achieve high refractive indices, tunable Abbe’s numbers, relatively low T g values, and other important properties. − …”

Phosphorus- and Sulfur-Containing High-Refractive-Index Polymers with High Tg and Transparency Derived from a Bio-Based Aldehyde

“…This is attributed to the fact that TVP-TH1 possesses a higher sulfide content. Although the n values of TVP-TH and TVP-TH2 decrease with the increase of wavelength, TVP-TH1 still has a high n value (1.683 at 900 nm), which is better than those of most HRIPs containing sulfur. − Moreover, TVP-TH1 and TVP-TH2 display very low extinction coefficients in the vis–NIR region (see Figure S3), suggesting their good optical transparency. For optical materials, Abbe’s number is another important parameter besides n . Abbe’s number ( v D ) is obtained according to eq reported in the literature, where n D , n F and n C are the n at 589.3, 486.1, and 656.3 nm.…”