SYNTHESIS AND CHARACTERIZATION OF WELL-DEFINED BLOCK COPOLYMERS CONTAINING PENDANT, SELF-COMPLEMENTARY QUADRUPLE HYDROGEN BONDING SITES

The title block copolymer (defined as PSUEA) containing pendant,self-complementary quadruple hydrogen bonding sites has been prepared successfully by three steps.First,poly(styrene-b-2-hydroxyethyl acrylate) (defined as PSHEA) was prepared by living radical polymerizing 2-hydroxyethyl acrylate (HEA) initiated by polystyrene (PSt) macroinitiator,which was prepared via nitroxide-mediated polymerization (NMP) technique.After treated by excessive 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI),PSHEA was transferred into an intermediate polymer (defined as PSIEA) with isocyanate groups in the second block.Finally,PSIEA was reacted with excessive 2-amino-4-hydroxy-6-methyl-pyrimidone (MIS) to obtain PSUEA bearing pendant quadruple hydrogen bonding 2-ureido-41H]-pyrimidone (Upy) units.Based on 1H-NMR,FT-IR and GPC analysis,all the polymers with well controlled structures were obtained.Preliminary thermal analysis of the block polymers indicated that the introduction of Upy units significantly increased the glass transition temperature.The possibility to form quadruple hydrogen bonding should make PSUEA suitable as new building component for supramolecular assembling.