SURFACE-INITIATED ATOM TRANSFER RADICAL POLYMERIZATION OF HYDROXYETHYL ACRYLATE FROM ACTIVATED CARBON POWDER WITH HOMOGENIZED SURFACE GROUPS

Abstract

The well-defined poly(hydroxyethyl acrylate) (PHEA) brushes were grafted from the surfaces of the activated carbon (AC) powder with the controlled/"living" radical polymerization technique. First, surface functional groups of the AC powder were homogenized to hydroxyl groups by oxidizing with nitric acid and then reducing with lithium tetrahydroaluminate ( LiAlH 4) at first. Second, the surface hydroxyl groups were treated with bromoacetylbromide, and the bromoacetyl groups were introduced. And in the third step, the bromoacetyl activated carbon ( BrA-AC ) powder were used as macro-initiators for the surface-initiated atom transfer radical polymerization (SI-ATRP) of hydroxyethyl acrylate (HEA) in the presence of 1,10-phenanthroline and Cu(I)Br as catalyst in a water system. The graft parameters calculated from the elemental analyses (EA) results, conversion of monemer (C%) and percentage of grafting (PG%) were 5.74% and 28.7%, respectively, after polymerizing for 5 h. The graft polymerizations exhibited the characteristics of a controlled/"living" polymerization, and no homopolymer was found in the proposed polymerizing process. The preparation procedure of the poly(hydroxyethyl acrylate) grafted activated carbon (PHEA-AC) powder was also investigated by X-ray photoelectron spectroscopy (XPS). The PHEA-AC powder is expected to be used as selective adsorbents because of their abundant homogenized surface hydroxyl groups.