Mega-supramolecules for energy conservation and fire safety using long end-associative telechelics in fuel

Liq. fuels (petroleum, diesel, kerosene, etc.) are the world's dominant power source (34̂ of global energy consumption, 32.5 Billion barrels in 2011). Transportation relies on liq. fuels, presenting the risk of explosive combustion in the event of impact. Ultra-long linear polymers offer the benefits of reduced risk of post-crash fires and reduced energy consumption used to transport fuel across the US. Problems with shear degrdn. and incompatibility with engine operation caused them to be largely abandoned since 1984. Here we provide an "existence proof" for supramols. that are so long that they confer the benefits of ultra-long covalent polymers (e.g., >4M g/mol polyisobutylene), without their deficiencies. Based on the statistical mechanics of ringchain equil., to form "mega-supramols." at low concn., very long building blocks are designed. Adopting the Hilmyer-Macosco protocol for ROMP of cyclooctadiene with CTAs bearing end-groups, improvements in monomer purifn. enabled synthesis of telechelics with unprecedented length (telechelic polymers with Mw>400 kg/mol). Simple carboxylic acid - tertiary amine pairs are designed to provide complementary endassocn. that is amenable to scale up; surprisingly, they also proved to be more effective than such multidentate "stickers" as Hamilton receptor and cyanuric acid. Steady shear viscometry confirmed the dramatic enhancement in the rheol. effect brought by longer backbone length. GPC-MALLS and SANS were performed to study the distributions and structures of supramols. Long end-associative polymers are as effective as ultralong linears-and have excellent shear resistance. Specifically, megasupramols. control post impact misting, which prevents hot fireballs from forming. In addn., megasupramols. reduce turbulent drag without degrading, relevant to energy conservation in fuel distribution pipelines. These "megasupramoleules" have no adverse effect on power output, fuel efficiency or emissions in unmodified diesel engines. In fact, they provide a 12̂ (p=0.002) redn. in diesel soot