Nitrogen solubilities in low‐density polyethylene at high temperatures and high pressures

Abstract

SYNOPSISAn apparatus for the determination of the solubility of gases in polymers at high pressure and high temperature is described. The solubilities of nitrogen in low-density polyethylene (PE800E) at 394-450 K at pressures between 10 and 125 atm are reported. Empirical correlations are obtained which represent the Flory-Huggins interaction parameter X, solubility coefficient &, and activity coefficient of dissolved gas R2 as functions of temperature and pressure for the above system. 0 1995 John Wiley & Sons, Inc.

Maximal cell density predictions for compressible polymer foams

“…These χ parameters correspond to a blowing agent of a "nitrogen" type, since we get higher solubilities at higher temperatures [14]. Other choices of χ parameters can give lower solubilities at higher temperatures which would correspond to "carbon dioxide" type blowing agents [15,16,17,18,19]. Figure 2 shows cell densities as a function of sample volume for the above choices of parameters corresponding to T = 1.5 and T = 2.0.…”

Experimental observations and modelling relating to foaming and bubble growth from pentane loaded polystyrene melts

“…where K H is the Henry's solubility coefficient and is a complex function of temperature and pressure for a given polymer melt with dissolved gas system (Lee and Flumerfelt, 1995). The sample is initially loaded above its saturation pressure (P sat ) to form a single phase melt of gas and polymer.…”

Transport Properties of Gases in Polymers: Experimental Methods

“…Introduced into a high-pressure (HP) cell, this balance allows to obtain tests at a pressure of 6 MPa and temperatures of about 80°C [18,19]. Some evolutions of this technique allow to perform measurements at a pressure of 12 MPa and a temperature up to 350°C with a resolution of 10 µg, for an initial weight of polymer sample of about 1 g [20,21]. By installing an electromagnetic coupling to transmit the sample weight to an external balance, it is possible to obtain a system called "magnetic suspension balance" [22].…”

“…Finally, the regulation system allows to regulate T m . Then, the output flow Q can be calculated from the formula: (20) For safety, the HP permeation equipment is placed in a cell located in an explosion-protected zone.…”