This paper describes the synthesis and characterization of epoxy resins based on (hexafluoroisopropylidene)diphenol (EFN) and p,p’-isopropylidenebisphenol (EBN), respectively and 4, 4’(hexafluoroisopropylidene)dipthalic-imideamine (IMAM), a curing agent. The synthesized epoxy resins and IMAM curing agent were characterized by Fourier Transform Infrared (FTIR) and 1H Nuclear Magnetic Resonance (...

BACKGROUND Ultraviolet (UV)-curing nail polishes based on acrylates or methacrylates are currently also available for non-professional use. The Swedish Medical Products Agency recently prohibited one brand of UV-curing polish, because several consumers reported undesirable effects after using it. OBJECTIVES To investigate whether consumers with undesirable effects after using the UV-curing na...

In this study, a fuzzy logic prediction model for 3, 7, 14 and 28 days compressive strength of lightweight concrete made with scoria aggregate and fly ash under different curing conditions (standard and air curing) was devised. In mixtures containing fly ash, 15% of Portland cement by weight was replaced with fly ash. The specimens were cured in standard curing conditions at temperature 20±2 °C...

An active approach for initiating rigidization in carbon-fiber reinforced polymer (CFRP) composites unites electrical resistivity to mechanical stiffening. Temperature control is implemented in efforts to reduce the curing time of the composite and to increase control of the curing process. Specifically, proportional-integral (PI) feedback control of internal resistive (Joule) heating establish...

OBJECTIVES Different light curing units are used for polymerization of composite resins. The aim of this study was to evaluate the degree of conversion (DC) and temperature rise in hybrid and low shrinkage composite resins cured by LED and Argon Laser curing lights. MATERIALS AND METHODS DC was measured using FTIR spectroscopy. For measuring temperature rise, composite resin samples were plac...

In order to study the thermal stability of accelerated-curing PF resin, the curing behavior of fresh PF resin was investigated in the presence of single accelerator of methylolurea derivatives (MMU), magnesium hydrate (Mg(OH)2), 25% aqueous solution of sodium carbonate (Na2CO3), and propylene carbonate (PC). Also their optimum combination was added in fresh PF resin. The thermal stability of cu...

This study investigated the influence of light-curing at high irradiances on micromechanical properties of resin cements. Three dual-curing resin cements and a light-curing flowable resin composite were light-cured with an LED curing unit in Standard mode (SM), High Power mode (HPM), or Xtra Power mode (XPM). Maximum irradiances were determined using a MARC PS radiometer, and exposure duration ...

AIM The aim of this study was to investigate the influence of light curing method, composite shade, and depth of cure on composite microhardness. METHODS AND MATERIALS Forty-eight specimens with 4 mm of depth were prepared with a hybrid composite (Filtek Z-100, 3M ESPE); 24 with shade A1 and the remaining with shade C2. For each shade, two light curing units (LCUs) were used: a quartz-tungste...

introduction: the aim of this study was to evaluate the influenceof different light curing systems and curing times on the micro-hardness of aresin modified glass ionomer. methods: forty two samples of resinmodified glass ionomer (rmgi) were prepared using stainless steel cylindrical mold(8 × 2 mm) and randomly divided into six groups of seven. three groups werecured with a quartz tungsten halo...