The Oldroyd-B fluid has become the starting point for almost all complex flow calculations and analysis involving behavior of dilute polymer solutions. reasons this are clear: based on kinetic theory high molecular weight “phantom” chains near equilibrium, resulting model, in its simplest form, produces a single mode description solution constitutive equation terms symmetric dyad order paramete...

The use of dental acrylics and composite resins in veterinary dentistry has become widespread. However their use is not without potential complications. All acrylics and composite resins produce an exothermic reaction during the polymerization process. The aim of the current study was to evaluate thermal conduction during the polymerization reaction of each material to offer clinical guidelines...

densities and viscosities of binary mixtures of methyl tert-butyl ether (mtbe) with 1-alkanols include 1-butanol, or +1-pentanol, or +1-hexanol, or +1-heptanol were measured as a function of composition from 293.15 to 308.15 k at atmospheric pressure. the temperatures studied were 293.15, 298.15, 303.15 and 308.15 k. the experimental results have been used to calculate the viscosity deviation d...

atom transfer radical polymerization (atrp) of styrene was carried out at 105°c and a monte carlo simulation was employed to model the system. the variations of monomer conversion, the initiator concentration, average molecular weight, and molecular weight distribution were evaluated as the reaction proceeded. according to the results obtained, for similar reaction time, monomer conversion is h...

To study the microscopic thermal aging mechanism of insulating paper cellulose through molecular dynamics simulation, it is important to select suitable DP (Degree of Polymerization) and force field for the cellulose model to shorten the simulation time and obtain correct and objective simulation results. Here, the variation of the mechanical properties and solubility parameters of models with ...

The aim of this study was to evaluate the polymerization stress and degree of conversion of a composite submitted to different photoactivation protocols. The composite Filtek Z350 was placed in the central perforation of a photoelastic disc and polymerized using a LED-based curing unit (BluePhase II--Ivoclar Vivadent) with energy density of 12, 24 or 36 J/cm2 using the following photopolymeriza...

The degree of polymerization of an acrylic resin repair material, as established by residual monomer estimation, was compared using three different polymerization methods, i.e. bench-cure, hydroflask-cure and microwave irradiation cure. The repair strength of a conventional heat-polymerized resin was then assessed following repairs using each of these three methods. The lowest level of residual...