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Semicrystalline Thermoplastic Elastomeric Polyolefins: Advances Through Catalyst Development And Macromolecular Design, Atsushi Hotta, Eric W. Cochran, Janne Ruokolainen, Vikram Khann, Glenn H. Fredrickson, Edward J. Kramer, Yong-Woo Shin, Fumihiko Shimizu, Anna E. Cherian, Phillip D. Hustad, Jeffrey M. Rose, Geoffrey W. Coates
Semicrystalline Thermoplastic Elastomeric Polyolefins: Advances Through Catalyst Development And Macromolecular Design, Atsushi Hotta, Eric W. Cochran, Janne Ruokolainen, Vikram Khann, Glenn H. Fredrickson, Edward J. Kramer, Yong-Woo Shin, Fumihiko Shimizu, Anna E. Cherian, Phillip D. Hustad, Jeffrey M. Rose, Geoffrey W. Coates
Eric W. Cochran
We report the design, synthesis, morphology, phase behavior, and mechanical properties of semicrystalline, polyolefin-based block copolymers. By using living, stereoselective insertion polymerization catalysts, syndiotactic polypropylene-block-poly(ethylene-co-propylene)-block-syndiotactic polypropylene and isotactic poly propylene-block-regioirregular poly propylene-block- isotactic polypropylene triblock copolymers were synthesized. The volume fraction and composition of the blocks, as well as the overall size of the macromolecules, were controlled by sequential synthesis of each block of the polymers. These triblock copolymers, with semicrystalline end-blocks and mid-segments with low glass-transition temperatures, show significant potential as thermoplastic elastomers. They have low Young's moduli, large strains at break, and better than 90% elastic recovery at …
Consequences Of Block Number On The Order-Disorder Transition And Viscoelastic Properties Of Linear (Ab)N Multiblock Copolymers, Lifeng Wu, Eric W. Cochran, Timothy P. Lodge, Frank S. Bates
Consequences Of Block Number On The Order-Disorder Transition And Viscoelastic Properties Of Linear (Ab)N Multiblock Copolymers, Lifeng Wu, Eric W. Cochran, Timothy P. Lodge, Frank S. Bates
Eric W. Cochran
The effect of block number on the order-disorder transition (ODT) and viscoelastic properties were studied for linear (AB) n multiblock copolymers. A series of symmetric poly(styrene-b-isoprene) n multiblocks ((SI) n, n = 1-10) were synthesized by anionic polymerization, and their order-disorder transition temperatures (T ODT) were located using dynamic mechanical spectroscopy. As n increases, T ODT approaches an asymptotic value, consistent with random phase approximation calculations. A systematic difference between the experimental and theoretical results is attributable to the effects of fluctuations, independent of the number of blocks. Addition of up to 20 vol % of a nonselective solvent depresses …
A Cooperative Molecular Modeling Exercise— The Hypersurface As Classroom, Christopher J. Cramer, Bethany L. Kormos, Paul Winget, Vanessa M. Audette, Jeremy M. Beebe, Carolyn S. Brauer, W.Russ Burdick, Eric W. Cochran, Brian M. Eklov, Timothy J. Giese, Yongseok Jun, Lakshmi S.D. Kesavan, Christopher R. Kinsinger, Mikhail E. Minyaev, Ramkumar Rajamani, Jonathon S. Salsbury, John M. Stubbs, Jack T. Surek, Jason D. Thompson, Vincent A. Voelz, Collin D. Wick, Ling Zhang
A Cooperative Molecular Modeling Exercise— The Hypersurface As Classroom, Christopher J. Cramer, Bethany L. Kormos, Paul Winget, Vanessa M. Audette, Jeremy M. Beebe, Carolyn S. Brauer, W.Russ Burdick, Eric W. Cochran, Brian M. Eklov, Timothy J. Giese, Yongseok Jun, Lakshmi S.D. Kesavan, Christopher R. Kinsinger, Mikhail E. Minyaev, Ramkumar Rajamani, Jonathon S. Salsbury, John M. Stubbs, Jack T. Surek, Jason D. Thompson, Vincent A. Voelz, Collin D. Wick, Ling Zhang
Eric W. Cochran
Quantum chemistry has been a staple of undergraduate curricula for several decades. For the most part, however, it has been the rare course in quantum chemistry that advances much beyond the hydrogen atom (or perhaps H2) in terms of describing the electronic structure of real molecular systems. Driven in part by staggering advances in computer technology during the last 15 years or so, which have rendered possible on a laptop calculations that once would have taxed the largest mainframes available, this situation now seems to be changing (1–3).