Synthesis and Properties of High‐Refractive‐Index Iodine‐Containing Polyacrylates

• Published in: ChemistrySelect (Weinheim) Vol. 7; no. 28
• Main Authors: Maekawa, Hiroyuki, Amano, Hikaru, Nishina, Ikuko, Kudo, Hiroto
• Format: Journal Article
• Language: English
• Published: 27.07.2022
• Subjects: abbe number; high refractive index; iodine; radical reaction
• ISSN: 2365-6549; 2365-6549
• DOI: 10.1002/slct.202201543

We examined the radical polymerization of 2,4,6‐triiodophenyl acrylate (TIPA), the chain‐transfer radical polymerization of TIPA in the presence of 4,4‐thiobisbenzenethiol (TBBT) or 4‐mercaptopyridine (MP), and the radical copolymerization of TIPA with 2‐hydroxyethyl acrylate (HEA) or 2‐(2‐ethoxyethoxy) ethyl acrylate (EEA), using AIBN as an initiator at 60 °C for 20 h. These reactions afforded poly(TIPA), TBBT‐poly(TIPA)m, MP‐poly(TIPA)m poly(TIPAm‐co‐HEAn) and poly(TIPAm‐co‐EEAn), respectively, with Mn values in the range of 3,180 to 46,550, in satisfactory yields. MP‐poly(TIPA)41 (Mn=6,880), poly(TIPA88‐co‐HEA12) (Mn=11,300), and poly(TIPA85‐co‐EEA15) (Mn=19,200) showed film‐forming ability, although poly(TIPA) and TBBT‐poly(TIPA)m did not. Among them, poly(TIPA85‐co‐EEA15) showed high values of refractive index (n) and Abbe number (ν), i. e., n=1.850 and ν=20.7. We investigated the polymerization of iodine‐containing polyacrylate. In the case of homopolymerization, the obtained polymers had poor solubility and did not show thin film forming ability. On the other hand, we examined chain transfer polymerization and copolymerization, and the resulting polymers had solubility and film forming ability and showed a refractive index of 1.695∼1.850. Furthermore, poly(TIPA85‐co‐EEA15) showed high values of refractive index (n) and Abbe number (ν), i. e., n=1.850 and ν=20.7.