Synthesis and Characterization of Semicrystalline Polyethylene-graft-Poly(acrylic acid) Copolymers

Hydrophilic polyolefin materials were prepared by grafting tBA from PE macroinitiators bearing functionalized norbornene units capable of initiating an ATRP. This method produced semicrystalline graft copolymers (PE-graft-PtBA) with narrow molecular weight distributions (1.2-1.4) and tunable tBA content (2-21 mol-%). Incorporation of tBA resulted in a decrease in crystallinity, but little change in the melting point of the products. Subsequently, the tBA moieties were converted into acrylic acid units through chemical and thermal means to generate PE-graft-PAA copolymers. The increased hydrophilicity of the resulting materials was verified by ATR-IR, solid-state C-13 NMR spectroscopy, contact angle measurements, and TGA.