I want to study the density, thermal expansion and thermal conductivity of polymers (like polyethylene) above their melting temperature. Kindly suggest me the name of the measuring instrument for this purpose. It will be great help if anyone can give some contacts in India where those facilities are available.
Thanks a lot for your attention.
I hope it will be helpful to you.
instrument :Thermomechanical Analysis(TMA)
Thanks a lot all of you for your kind suggestions....... I guess TMA and KD2 will serve my purposes......
You have also C-Therm Technologies TCi Thermal Property system, which enables measurements of thermal conductivity (provided by Setaram) from -50°C up to 200°C
Often we have access to the density at a single temperature, and we may want to estimate the density at some higher temperature(s), while we may find reasonable to support that extrapolation on the (possibly) available viscosity data and thermal expansion data. In the following, this issue is addressed. It can be noticed that for the dynamic viscosity vs. temperature dependency of polymers, we may possibly accept the Williams-Landel-Ferry viscosity model (*) μ = μº·exp [-C1·ΔT / (C2 + ΔT)], where C1 and C2 are empiric parameters, μº is the dynamic viscosity of the polymer at the reference temperature, Tº ≥ Tg, while μ applies to the actual temperature considered (T), exceeding Tº by a temperature interval, ΔT = T-Tº. Let us accept that the thermal expansion coefficient, defined as α = (1/ρ)·[dρ / d(ΔT)], can be taken as approximately constant (α ≈ αº). For the same temperature interval: ρ = ρº·exp(-αº·ΔT), where is the density for the reference temperature, ρº. For the kinematic viscosity (ν = μ / ρ; νº = μº / ρº) the following correlation would hold: ν = νº·exp [-C1·ΔT / (C2 + ΔT)] / exp(-αº·ΔT), what rewrites as: ln (ν / νº) = [αº - C1/(C2 + ΔT)]·ΔT. We may use this correlation to estimate kinematic viscosities and/or densities at higher temperatures than Tg. For a given polymeric material with all relevant properties known, we may approximately evaluate this correlation by checking the linearity of a ln (ν / νº) / ΔT vs. 1/(C2 + ΔT) plot, having αº as intercept and -C1 as slope.
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