Effect of acid-base properties of the surface of alumina on reactivity with epoxy compounds

By the pK-spectroscopy method the acid-base properties of the surface of polymorphic modifications of alumina (boehmite, γ-Al2O3, corundum) were researched. On the basis of 4pK-model it is shown that only for γ-Al203 and γ-+AlO(OH) there are acid-base canters described by the equation: -Al-OH2Al-OH + H+ with pK1 ≈ 4. By methods of FTIR-spectroscopy, Differential Scanning Calorimetry, chemical analysis the research of physical and chemical processes proceeding at introduction of polymorphic modifications of alumina in epoxy-polymeric matrix was carried out. It is shown that γ – Al2O3 and γ – AlO(OH) at the expense of presence of more active surface groups c, are the most reactive-capable modifying fillers of epoxy oligomers, entering into a chemical reaction with them.