EFFECT OF MOLECULAR ARCHITECTURE ON DBS-INDUCED BLOCK-COPOLYMER GELS - A RHEOLOGICAL STUDY

Dibenzylidene sorbitol (DBS) is capable of gelling a variety of organi c solvents and polymeric materials by forming a rigid, 3-D hydrogen-bo nded network. In this work, two poly(siloxane)/poly(propylene oxide) s egmented copolymers of equal composition and molecular weight, but dif ferent architectures (endblocked vs. pendant), as well as a pure poly( propylene oxide), have been gelled with DBS. We have investigated the dynamic rheological properties of these gels to ascertain the effect o f copolymer architecture, PDMS comonomer and DBS concentration on netw ork formation.