Synthesis of HBPE-b-PS copolymers with controlled molecular weights and low polydispersities via in situ ATRP

The functionalized polyolefins are important in both fundamental research and industrial practice. However, the direct processes have been greatly limited by some fundamental chemical difficulties, such as catalyst poisoning. Also there is no facile reaction site on most polyolefins by chemical modification. We report here in an in situ ATRP method for the synthesis of hyperbranched polyethylene block polystyrene copolymers with controlled molecular weights and low polydispersities. First we introduced reactive terminal groups to hyperbranched polyethylene branches as macroinitiators by end-quenching reaction with injected styrene derivatives in the Pd-catalyzed ethylene polymerization system. And then hyperbranched polyethylene-based block polystyrene copolymers were directly synthesized via in situ ATRP method by using the macroinitiators. The resulting hyperbranched polyethylene block polystyrene copolymers have narrow distribution (from 1.01 to 1.44) of molecular weights, controllable molecular weights, and good compatibilities.