Synthesis and Characterization of Novel Quaternary Ammonium Urethane-Dimethacrylate Monomers—A Pilot Study

Abstract

Six novel urethane-dimethacrylate analogues (QAUDMAs) were synthesized and characterized. They consisted of the 2,4,4,-trimethylhexamethylene diisocyanate (TMDI) core and two methacrylate-terminated wings containing quaternary ammonium groups substituted with alkyl chains of 8, 10, 12, 14, 16, or 18 carbon atoms. QAUDMAs, due to the presence of quaternary ammonium groups, may have possible antibacterial effects. Since they showed satisfactory physicochemical properties, they will be subjected to further research towards the development of dental composites with a capacity to reduce secondary caries. The synthesis of QAUDMAs included three stages: (i) transesterification of methyl methacrylate (MMA) with N-methyldiethanolamine (MDEA), (ii) N-alkylation of the tertiary amino group with alkyl bromide, and (iii) addition of TMDI to the intermediate achieved in the second stage. The formation of QAUDMAs was confirmed by 1H and 13C NMR. They were characterized for density (dm), viscosity (η), refractive index (RI), glass transition temperature (Tg), polymerization shrinkage (S), and degree of conversion (DC). QAUDMAs were yellow, viscous resins (the η values ranged from 1.28 × 103 to 1.39 × 104 Pa·s, at 50 °C). Their RI ranged from 1.50 to 1.52, Tg from −31 to −15 °C, DC from 53 to 78%, and S from 1.24 to 2.99%, which is appropriate for dental applications.

Melt‐Versus Solution‐Extrusion Additive Manufacturing of Poly(methyl methacrylate) Medical Implant Prototypes

“…[ 9 ] Furthermore, PMMA‐Raw, PMMA‐Fil, and PMMA‐FFF showed two signals at 6.07 and 5.73 ppm likely due to vinyl protons of unreacted methyl methacrylate (MMA) monomer present in the commercial polymer powder. [ 19 ] These signals, as well as that at 3.72 ppm relevant to methoxy proton of MMA, [ 20 ] were not present in PMMA‐CAWS samples likely due to extraction of the monomer during the polymer solution coagulation in ethanol. This represents an advantage of the CAWS approach in relationship to the toxicity of residual MMA, which if leached after implantation can cause unwanted reactions.…”

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

“…The HAMA was synthesized from methyl methacrylate (MMA; Acros Organics, Geel, Belgium) and N -methyldiethanolamine (MDEA; Acros Organics, Geel, Belgium). All syntheses were performed following the procedures described in a previous report [ 23 ]. Camphorquinone (CQ), 2-dimethylaminoethyl methacrylate (DMAEMA), Bis-GMA, TEGDMA, and UDMA were purchased from Sigma-Aldrich, St. Louis, MO, USA and used as received.…”

“…This study provides insights relevant for preparing bioactive dimethacrylate matrices for dental composite restorative materials. Our proposal is based on the utilization of quaternary ammonium urethane-dimethacrylate analogues (QAUDMA-m, where m is number of carbon atoms in the N -alkyl substituent) ( Figure 1 ) [ 23 ]. These compounds comprise a 2,2,4-trimethylhexamethylene diisocyanate (TMDI) core and two methacrylate-terminated wings.…”

“…The quaternary ammonium groups, each substituted with an N -alkyl chain of 8, 10, 12, 14, 16, or 18 carbon atoms, are located in the middle of each wing. Because the QAUDMA-m monomers were viscous resins with suitable physicochemical parameters (refractive index ( RI ) from 1.50 to 1.52, monomer glass transition temperature ( Tg m ) from −31 to −15 °C, degree of conversion ( DC ) from 0.53 to 0.78, experimental polymerization shrinkage ( S e ) from 1.24 to 2.99%) [ 23 ], we evaluated them in the context of their copolymers with common dental dimethacrylates: bisphenol A glycerolate dimethacrylate (Bis-GMA), urethane-dimethacrylate monomer (UDMA), and triethylene glycol dimethacrylate (TEGDMA) ( Figure 1 ).…”

Cytotoxicity and Microbiological Properties of Copolymers Comprising Quaternary Ammonium Urethane-Dimethacrylates with Bisphenol A Glycerolate Dimethacrylate and Triethylene Glycol Dimethacrylate

“…Our research group has been working on new di-QAMs and their copolymers. These monomers include a series of urethane-dimethacrylates with two quaternary ammonium groups (QAUDMA-m, m being related to the length of the N-alkyl substituent and corresponding to 8, 10, 12, 14, 16, and 18 carbon atoms) ( Figure 1 ) [ 31 ]. QAUDMA-m monomers are similar in chemical structure to the so-called urethane dimethacrylate (UDMA) monomer due to the following structural elements: (i) the 1,6-diisocyanato-2,4,4-trimethylhexylene (TMDI) core, (ii) two arms attached to the core by carbamate linkages, and (iii) methacrylate group at the end of each arm.…”