2005 Volume 78 Issue 12 Pages 461-466
Theoretical aspects of polymer-polymer interface are discussed. The interfacial thickness, the interfacial tension, and the adhesive strength are described as a function of the interaction parameter and the molecular weights of component polymers. When both component polymers have reactive sites, the coupling reaction takes place at the interface and the block or graft copolymers are formed. Melt-mixing of such reactive system is called “reactive blending” and “reactive processing”. By an emulsifying effect of the in situ-formed copolymer, the morphology could be tuned up; i.e., the size of dispersed particles can be reduced down to sub-μm to optimize the material properties. This may be a commonly accepted story for the ambiguous but convenient term “compatibilization”. Another interfacial behavior recently found is the pull-out of the in situ-formed copolymer by the external shear forces. It renders a new approach for the 10nm morphology control in reactive blending. Such interfacial aspects are successfully applied for the materials design; e.g., super-tough polyamide, high-temperature polyamide alloy for Pb-free solder, high-temperature poly(phenylene ether) alloy, and non-viscoelasic nylon alloy. The dynamic vulcanization is a unique reactive blending which leads to a two-phase material consisting of the crosslinked rubber particles and a matrix of thermoplastic polymer. Strain recovery mechanism of the two-phase material is discussed.
