title: Chemical characterization and flexural strength of a denture base acrylic resin with monomer 2-tert-butylaminoethyl methacrylate.
abstract: OBJECTIVE
  The objectives of this study were to investigate the flexural strength (FS) and chemical interaction between 2-tert-butylaminoethyl methacrylate (TBAEMA) and a denture base acrylic resin.
  
  
  METHODS
  Specimens were divided into five groups according to the concentration of TBAEMA incorporated in acrylic resin Onda-Cryl (0%, 1%, 2%, 3%, 4%) and were submitted to Fourier transform infrared spectroscopy (FTIR), electron spectroscopy for chemical analysis (XPS-ESCA), and differential scanning calorimetry (DSC) analyses. FS of the specimens was tested, and results were analyzed by ANOVA/Tukey's test (α < 0.05).
  
  
  RESULTS
  Different nitrogen ratios were observed on specimens' surfaces: 0.36%, 0.54%, 0.35%, and 0.20% for groups 1%, 2%, 3%, and 4%, respectively. FTIR indicated copolymerization of acrylic resin and TBAEMA, and DSC results demonstrated a decrease in glass transition temperature (Tg ). Significant differences were found for FS (p < 0.05). The mean values were 91.1 ± 5.5,(A) 77.0 ± 13.1,(B) 67.2 ± 12.5,(B) 64.4 ± 13.0,(B) and 67.2 ± 5.9(B) MPa for groups 0%, 1%, 2%, 3% and 4%, respectively (same superscript letters indicate no significant difference).
  
  
  CONCLUSIONS
  The incorporation of TBAEMA in acrylic resin resulted in copolymerization and the presence of amine groups on specimens' surfaces, and in decreases of Tg and FS.
authors.affiliation: Department of Dental Materials and Prosthodontics, Araraquara Dental School, UNESP-São Paulo State University, Araraquara, Brazil.
authors.forename: Larissa Santana
authors.initials: LS
authors.lastname: Rodriguez
authors.forename: André Gustavo
authors.initials: AG
authors.lastname: Paleari
authors.forename: Gabriela
authors.initials: G
authors.lastname: Giro
authors.forename: Norberto Martins
authors.initials: NM
authors.lastname: de Oliveira Junior
authors.forename: Ana Carolina
authors.initials: AC
authors.lastname: Pero
authors.forename: Marco Antonio
authors.initials: MA
authors.lastname: Compagnoni
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D055598:Chemical Phenomena; D003764:Dental Materials / Q000737:chemistry*; D003819:Denture Bases; D005898:Glass / Q000737:chemistry; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry*; D046032:Microscopy, Energy-Filtering Transmission Electron; D009584:Nitrogen / Q000032:analysis; D044367:Phase Transition; D018583:Pliability; D058105:Polymerization; D019904:Polymethyl Methacrylate / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013314:Stress, Mechanical; D044366:Transition Temperature
chemical_list: D000180:Acrylic Resins; D003764:Dental Materials; D008689:Methacrylates; C539103:onda cryl; C522816:poly(2-(tert-butylamino)ethyl methacrylate); D019904:Polymethyl Methacrylate; D009584:Nitrogen