XPS INVESTIGATIONS OF ACID-BASE INTERACTIONS IN ADHESION .4. USE OF TRICHLOROMETHANE AS A MOLECULAR PROBE FOR THE QUANTITATIVE ASSESSMENT OF POLYMER BASICITY

Trichloromethane has been used as a molecular probe for the assessment of acid-base properties of polymers in the solid state. It is shown i n this paper that when CHCl3 is sorbed in polymers it undergoes a nega tive XPS chemical shift as a result of acid-base interactions. Followi ng the FTIR approach of Fowkes, we determined DELTAH(AB), the enthalpy of acid-base adduct formation, for the different polymer-CHCl3 adduct s, and found that the XPS binding energy (E(b)) of the Cl 2p3/2 line i s linearly related to DELTAH(AB). The relationship is of the form -DEL TAH(AB)/kcal mol-1=228.8-1.14 E(b)/eV.