TIME-DEPENDENT REACTIVE COUPLING AT POLYMER-POLYMER INTERFACES

Using recently calculated rate coefficients for reactive coupling of c hains at polymer-polymer interfaces, we describe the diffusion-control led growth of diblock copolymer at the interface between dissimilar mo lten homopolymer films. The growth exhibits several regimes, successiv ely controlled by (1) the quasilocal reaction rate near the interface, (2) center-of-mass diffusion of reactive homopolymer to the interface , and (3) the diffusion barrier presented by the growing copolymer lay er. Our results can be tested by time-dependent measurements of the co polymer coverage or concentration of reacted coupling groups.