Physicochemical Properties of Novel Copolymers of Quaternary Ammonium UDMA Analogues, Bis-GMA, and TEGDMA.

This study aimed to elucidate the physicochemical properties of copolymers comprising 40 wt.% bisphenol A glycerolate dimethacrylate (Bis-GMA), 40 wt.% quaternary ammonium urethane-dimethacrylate analogues (QAUDMA-m, where m corresponds to the number of carbon atoms in the N -alkyl substituent), and 20 wt.% triethylene glycol dimethacrylate (TEGDMA) copolymers (BG:QAm:TEGs). The BG:QAm:TEG liquid monomer compositions and reference compositions (40 wt.% Bis-GMA, 40 wt.% urethane-dimethacrylate (UDMA), 20 wt.% TEGDMA (BG:UD:TEG) and 60 wt.% Bis-GMA, 40 wt.% TEGDMA (BG:TEG)) were characterized in terms of their refractive index ( RI ) and monomer glass transition temperature ( Tg m ) and then photocured. The resulting copolymers were characterized in terms of the polymer glass transition temperature ( Tg p ), experimental polymerization shrinkage ( S e ), water contact angle ( WCA ), water sorption ( WS ), and water solubility ( SL ). The prepared BG:QAm:TEG liquid monomer compositions had RI in the range 1.4997-1.5129, and Tg m in the range -52.22 to -42.12 °C. The BG:QAm:TEG copolymers had Tg p ranging from 42.21 to 50.81 °C, S e ranging from 5.08 to 6.40%, WCA ranging from 81.41 to 99.53°, WS ranging from 25.94 to 68.27 µg/mm 3 , and SL ranging from 5.15 to 5.58 µg/mm 3 . Almost all of the developed BG:QAm:TEGs fulfilled the requirements for dental materials (except BG:QA8:TEG and BG:QA10:TEG, whose WS values exceeded the 40 µg/mm 3 limit).