Extrusion and spinning of Nylon-6,6/supercritical carbon dioxide mixtures

Extrusion and spinning of nylon-6,6/CO2 was conducted in a twin-screw extruder line and the effects of carbon dioxide on the spun filaments morphology and tensile properties were investigated. The study is divided into two major sections. In the first one, the interaction between CO2 and nylon-6,6 melt is explored by investigating: (i) the CO2 solubility in the nylon melt, (ii) the effect of CO 2 on the nylon shear viscosity, and (iii) the hydrogen bond breaking in nylon-6,6 melts. In the second section, an attempt is made to establish feasible conditions for spinning of nylon-6,6/CO2 mixtures, to produce nylon filaments and to study the effect of CO2 on some properties of the spun filaments.; The solubility of CO2 in molten nylon was determined from swelling and viscosity measurements, and it was found to be less than 5% for our experimental temperature and pressure ranges. This value was used as a guide in establishing conditions for the spinning experiments. (Abstract shortened by UMI.)...