Mechanical behavior and structure of single beads of homogeneous and macroporous styrene–divinylbenzene copolymers

摘要

AbstractThe stress–stain and ultimate behavior in compression of homogeneous and macroporous beads of styrene–divinylbenzene copolymers has been investigated in the dry state or in equilibrium with toluene, acetone, methanol, and water. The penetration modulusAindicates sensitively the transition from the glassy into the rubbery state induced by an increase in temperature or swelling. For macroporous copolymers,Aof the glassy polymers is mainly determined by the porosityP, while in the rubbery region it primarily depends on the matrix structure (degree of crosslinking and concentration and composition of the diluent). The high value of the slopesof theAvs.Pdependence (s ∼ −3) for macroporous copolymers is evidence of the complex deformation mechanism (bucking of pore walls). The relative compression at break, εb=0.3–0.4, is independent of the composition, and the compressive strength is roughly proportional to the penetrati