Polyesters, ionic force

Other types of attractive forces that can help promote crystallinity are dipole-dipole and ionic interactions. The former occur with molecules containing atoms with different electronegativities (for example, a polyester), while the latter are found in polymers containing functional groups that can ionize, such as carboxylic acids. An example of each type is drawn here ... 

Nonionics have been shown also to be more effective than ionics in the removal of oily soil from relatively nonpolar substrates (polyester, nylon). On cotton, however, a relatively hydrophilic fiber, anionics can outperform nonionics in detergency, and both of these are superior to cationics (Fort, 1968). The effects here may be due to differences in the orientation of adsorption of the different types of surfactants on the different substrates. On nonpolar substrates and soils, POE nonionics are adsorbed (Chapter 2) from aqueous solution via dispersion forces or hydrophobic bonding with their hydrophobic POE groups oriented toward the adsorbent and their hydrophilic POE groups toward the bath. Adsorption of the surfactant in this fashion on the substrate lowers the substrate-bath interfacial tension jSB and facilitates soil removal (equation 10.3) adsorption in this fashion on both substrate and soil produces a steric barrier that inhibits soil redeposition. 

Polymer I was an amorphous water-soluble polymer with an inherent viscosity of 0.33 and a Tg of 26°C. The Mn and were 6,419 and 15,546 respectively. The ionic polyester displayed excellent adhesive properties as shown in Figure 1. Absolute peel force values could not be obtained... 

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