DEVELOPMENT OF BORON CAGE COMPOUNDNANOCOMPOSITE ELASTOMERS

摘要

Boron cage compounds (BCC) are a class of icosahedral closed cage molecules (carboranes -closo--C_2B_(10)H_(12), and dodecaborane anions or boranes - [closo-B_(12)H_(12)]~(2-)) They are ridged, 3-dimensional, chemically modifiable, and of high boron content. Although a few isolated cases serve as precedent, the synthesis, polymerization and copolymerization, and blending/compounding of BCCs in a variety of host polymer matrixes has not been systematically examined for the purpose of studying the resulting rheological properties. In collaboration with Prof.s Hawthorne and Lee of the University of Missouri-Columbia's International Institute of Nano and Molecular Medicine (I~2NM~2) chemically modified boron cage compounds have been incorporated into polyolefin elastomers such as ethylene vinyl acetate (EVA) copolymers and partially hydroxylated EVA elastomer, among others. The chemical structure/physical property relationships of resulting BCC nanocomposites have been examined via their rheological, physical, and thermal properties, with reinforcement and plasticization being observed. The ~(10)B isotope of boron has a high cross-section for neutrons and the resulting BCC nanocomposites possess inherent neutron absorbing/shielding characteristics, in addition to important thermal and mechanical properties. A technology platform based on BCC nanocomposites has been developed, which has broad material application implications.