SURFACE-TENSION OF MELT POLYMER BRUSHES AND DIBLOCK COPOLYMERS

We present a crude discussion of the surface tension of a melt of grafted polymers. The theory depends on the energy, DELTAa2, gained by placing a chain end at the brush surface. It thus depends sensitively on the end distribution of chain ends near the tip of the brush. The three regimes, DELTAa2/kT << 1, almost-equal-to 1, > 1, previously discussed by de Gennes1 for an ungrafted melt, are studied, with particular reference to the dependence of the surface tension on the degree of polymerization. The specific example of a diblock copolymer melt with a lamellar structure is discussed.