Numerical Study Using Microstructure Based Finite Element Modeling of the Onset of Convective Heat Transfer in Closed-Cell Polymeric Foam.

The thermal performance of closed-cell foams as an insulation device depends on the thermal conductivity. In these systems, the heat transfer mode associated with the convective contribution is generally ignored, and studies are based on the thermo-physical properties that emerge from the conductive contribution, while others include a term for radiative transport. The criterion found in the literature for disregarding convective heat flux is the cell diameter; however, the cell size for which convection is effectively suppressed has not been clearly disclosed, and it is variously quoted in the range 3-10 mm.

Miniemulsion copolymerization of (meth)acrylates in the presence of functionalized multiwalled carbon nanotubes for reinforced coating applications.

Film forming, stable hybrid latexes made of methyl metacrylate (MMA), butyl acrylate (BA) and 2-hydroxyethyl methacrylate (HEMA) copolymer reinforced with modified multiwalled carbon nanotubes (MWCNTs) were synthesized by in situ miniemulsion polymerization. The MWCNTs were pretreated by an air sonication process and stabilized by polyvinylpyrrolidone. The presence of the MWCNTs had no significant effect on the polymerization kinetics, but strongly affected the polymer characteristics ( and insoluble polymer fraction).

Super-enhanced particle nucleation in styrene emulsion polymerization in the presence of sodium styrene sulfonate.

The styrene (St) emulsion polymerization using Aerosol MA80 as surfactant and in the presence of sodium styrene sulfonate (NaSS) was studied. The effect of NaSS content was assessed using MA80 concentrations below and at the critical micellar concentration. It was found that at the higher NaSS and MA80 contents, the number of particles (N) reaches a maximum of the order of 10particles/cm water, a huge value that has never been reported.