Gas and Vapor Transport in Clay Filled Copolyesteramides

Abstract

In recent years, macromolecular self-assembling (MSA) polymers have attracted a great deal of interest. These polymers have low molecular weight and self-assemble through secondary interactions such as hydrogen bonding. Polymer self-assembly causes the solid state polymer to take on properties similar to those of polymers with significantly higher molecular weights. These materials separate processability from solid state physical properties. Although the physical properties of MSA polymers are sufficient for many end uses, it is believed that further opportunities would be available if the gas and vapor transport properties of these materials could be enhanced. In an effort to improve barrier properties both organic functionalized and untreated montmorillonite clays were added to the MSA to change the gas and vapor transport properties of the composites from those of the neat polymer. The addition of clays increased melt viscosity for these materials with increasing clay loading. Both types of clays reduced O2 transport, but the untreated clay increased water vapor transport with increasing clay loading. This is in contrast to the behavior of the organic functionalized clay, which experienced a reduction of water vapor transport that was similar to the loss in O2 transport.