Macromolecules, Vol.35, No.23, 8745-8750, 2002
Synthesis and characterization of novel complementary multiple-hydrogen bonded (CMHB) macromolecules via a Michael addition
The synthesis and characterization of novel complementary multiple hydrogen-bonded poly(styrene) (CMHB-PS) oligomers possessing controlled molecular weights and narrow molecular distributions are described. Novel CMHB-PS oligomers comprising terminal heterocyclic base units were synthesized in a controlled fashion via derivatization of well-defined hydroxyl-terminated PS. The heterocyclic-terminated oligomers were synthesized via a Michael addition. of the corresponding heterocyclic compounds such as adenine, thymine, and 2,6-purine with acrylated PS. The acrylated PS precursors were prepared in a quantitative fashion via reaction of hydroxyl-terminated PS with acryloyl chloride in the presence of triethylamine. Terminal heterocyclic bases were introduced via a Michael addition in the presence of potassium tert-butoxide (t-BuOK). Novel CMHB-PS aggregates were prepared via subsequent solution blending of PS with complementary heterocyclic base units. H-1 NMR analysis confirmed that a 1: 1 mixture of adenine-PS or purine-PS with thymine-PS formed complementary multiple hydrogen bonding and exhibited thermoreversibility. In addition, H-1 NMR analysis confirmed that complementary hydrogen bonds dissociated at 95 degreesC in deuterated toluene.