Synthesis of poly(alkenoic acid) with L-leucine residue and methacrylate photopolymerizable groups useful in formulating dental restorative materials.
To develop resin-modified glass ionomer materials, we synthesized methacrylate-functionalized acrylic copolymer (PAlk-LeuM) derived from acrylic acid, itaconic acid and N-acryloyl-L-leucine using (N-methacryloyloxyethylcarbamoyl-N'-4-hydroxybutyl) urea as the modifying agent. The spectroscopic (proton/carbon nuclear magnetic resonance, Fourier transform infrared spectroscopy) characteristics, and the gel permeation chromatography/Brookfield viscosity measurements were analysed and compared with those of the non-modified copolymer (PAlk-Leu). The photocurable copolymer (PAlk-LeuM, ~14 mol% methacrylate groups) and its precursor (PAlk-Leu) were incorporated in dental ionomer compositions besides diglycidyl methacrylate of bisphenol A (Bis-GMA) or an analogue of Bis-GMA (Bis-GMA-1), triethylene glycol dimethacrylate and 2-hydroxyethyl methacrylate. The kinetic data obtained by photo-differential scanning calorimetry showed that both the degree of conversion (60.50-75.62%) and the polymerization rate (0.07-0.14 s(-1)) depend mainly on the amount of copolymer (40-50 wt.%), and conversions over 70% were attained in the formulations with 40 wt.% PAlk-LeuM. To formulate light-curable cements, each organic composition was mixed with filler (90 wt.% fluoroaluminosilicate/10 wt.% hydroxyapatite) into a 2.7:1 ratio (powder/liquid ratio). The light-cured specimens exhibited flexural strength (FS), compressive strength (CS) and diametral tensile strength (DTS) varying between 28.08 and 64.79 MPa (FS), 103.68-147.13 MPa (CS) and 16.89-31.87 MPa (DTS). The best values for FS, CS and DTS were found for the materials with the lowest amount of PAlk-LeuM. Other properties such as the surface hardness, water sorption/water solubility, surface morphology and fluorescence caused by adding the fluorescein monomer were also evaluated.
a Department of Polyaddition and Photochemistry , Petru Poni Institute of Macromolecular Chemistry , 41 A Gr. Ghica Voda Alley, Iasi 700487 , Romania.
Tinca
T
Buruiana
Marioara
M
Nechifor
Violeta
V
Melinte
Viorica
V
Podasca
Emil C
EC
Buruiana
D060326:Chemistry Techniques, Synthetic; D002626:Chemistry, Pharmaceutical; D003764:Dental Materials / Q000737:chemistry*; D007930:Leucine / Q000737:chemistry*; D008689:Methacrylates / Q000737:chemistry*; D055668:Photochemical Processes; D058105:Polymerization; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry*; D013386:Succinates / Q000737:chemistry; D014508:Urea / Q000737:chemistry
D003764:Dental Materials; D008689:Methacrylates; D011108:Polymers; D013386:Succinates; C008384:methacrylic acid; D014508:Urea; D007930:Leucine; C005229:itaconic acid
amino acid derivative; mechanical properties; photopolymerization; resin-modified glass ionomer