Failure Envelopes of Paint Films as Related to Pigmentation and Snelling

Abstract

A suitable presentation of the tensile properties of paint films is obtained by means of T. Smith's failure envelope. The viscoelastic states of material appear distinctly on the failure envelope. Technological properties, such as strength, toughness and deformability, can also be evaluated in this way. Films of linseed alkyd, pigmented with Pb[3]O[ 4], MgO and ZnO, exhibited a shift to the energy-elastic state with increasing pigmentation. In the swollen state, this tendency is markedly reduced by swelling of the binder. The "active" effect of the pigments is diminished at higher pigment volume concentration, since reactive groups in the binder may then be lacking. For systems with inactive pigments, such as urea resin/Fe[2]O[3] and PVC- copolymer/TiO[2], failure envelopes in the dry and swollen state were found which indicate no essential change in the viscoelastic character of the films. Measurements of the systems studied could be explained qualitatively on the basis of theoretical ideas derived by T. Smith, Bueche and Halpin.SOMMAIRE FRANCAIS A SUIVREPeer reviewed: NoNRC publication: Ye