Results 261 to 270 of about 131,598 (304)
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Heterobifunctional poly(ethylene oxide)
Polymer Bulletin, 1994Well-defined poly(ethylene oxide)s with a primary amino group at one end and a hydroxyl group at the other terminus were synthesized with new sila-protected amino functionality initiator, potassium N-[2-(2,2,5,5-tetramethyl-1-aza-2,5-disilacyclopentyl)-ethyl]methyl amide [1b].
Yong Joo Kim +6 more
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Electrochimica Acta, 2008
Abstract The effect of LiClO 4 on the ionic transport behavior in poly(ethylene oxide) 20 –poly(propylene oxide) 70 –poly(ethylene oxide) 20 (P123) polymer electrolyte was studied. Its conductivity reaches maximum as molar ratio between ether O atoms and lithium ions [ n (O)/ n (Li)] equals 8. The results show that LiClO 4 could interact with P123
Xiao-Liang Wang +5 more
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Abstract The effect of LiClO 4 on the ionic transport behavior in poly(ethylene oxide) 20 –poly(propylene oxide) 70 –poly(ethylene oxide) 20 (P123) polymer electrolyte was studied. Its conductivity reaches maximum as molar ratio between ether O atoms and lithium ions [ n (O)/ n (Li)] equals 8. The results show that LiClO 4 could interact with P123
Xiao-Liang Wang +5 more
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Macromolecules, 1995
Phase behavior of ethylene oxide (EO)-propylene oxide (PO)-ethylene oxide triblock copolymers in water has been investigated, by using 2 H NMR and polarizing microscopy, as functions of both concentration and temperature. Seven copolymers, having wide variations of composition and molecular weight, are used.
Kewei Zhang, Ali Khan
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Phase behavior of ethylene oxide (EO)-propylene oxide (PO)-ethylene oxide triblock copolymers in water has been investigated, by using 2 H NMR and polarizing microscopy, as functions of both concentration and temperature. Seven copolymers, having wide variations of composition and molecular weight, are used.
Kewei Zhang, Ali Khan
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The Journal of Physical Chemistry B, 2005
Aqueous poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO109-PPO41-PEO109) copolymers are nonionic surfactants that self-organize to form aggregate structures with increasing temperature or concentration. We have studied two concentrations over a range of temperatures so that the copolymers are in one of three microphases: unimers ...
Christian D, Grant +3 more
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Aqueous poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO109-PPO41-PEO109) copolymers are nonionic surfactants that self-organize to form aggregate structures with increasing temperature or concentration. We have studied two concentrations over a range of temperatures so that the copolymers are in one of three microphases: unimers ...
Christian D, Grant +3 more
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2009
Abstract Introduction New types of linear low-density polyethylenes (LLDPE) based on the metallocene catalyst technology was introduced in the market place in 1991. There are now a number of well-established metallocene PE families commercially available and new products are constantly being introduced into the marketplace.
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Abstract Introduction New types of linear low-density polyethylenes (LLDPE) based on the metallocene catalyst technology was introduced in the market place in 1991. There are now a number of well-established metallocene PE families commercially available and new products are constantly being introduced into the marketplace.
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Journal of Chemical Theory and Computation, 2006
We present a multiscale modeling approach for simulation of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer micelles in aqueous solution. We rely on systematic elimination of computationally expensive degrees of freedom yet retain implicitly their influence on the remaining degrees freedom in a coarser-grained model ...
Dmitry, Bedrov +2 more
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We present a multiscale modeling approach for simulation of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer micelles in aqueous solution. We rely on systematic elimination of computationally expensive degrees of freedom yet retain implicitly their influence on the remaining degrees freedom in a coarser-grained model ...
Dmitry, Bedrov +2 more
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Macromolecules, 1995
Triblock copolymers of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO) form lamellar mesophases at low temperatures. The order-to-disorder transition is closely related to the melting transition of the PEO subunit. When water is incorporated into the copolymer melt, a single phase is formed at high temperatures, which is possibly a lamellar ...
Mortensen, Kell, BROWN, W, JORGENSEN, E
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Triblock copolymers of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO) form lamellar mesophases at low temperatures. The order-to-disorder transition is closely related to the melting transition of the PEO subunit. When water is incorporated into the copolymer melt, a single phase is formed at high temperatures, which is possibly a lamellar ...
Mortensen, Kell, BROWN, W, JORGENSEN, E
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Advances in Colloid and Interface Science, 2006
A number of results reported on the kinetics of exchange of triblock copolymers poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide), PEO-PPO-PEO, between micelles and the intermicellar aqueous solution are reviewed and analyzed to extract the rate constants k(+) for the entry of a copolymer into a micelle and k(-) for the exit of a ...
Raoul, Zana +2 more
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A number of results reported on the kinetics of exchange of triblock copolymers poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide), PEO-PPO-PEO, between micelles and the intermicellar aqueous solution are reviewed and analyzed to extract the rate constants k(+) for the entry of a copolymer into a micelle and k(-) for the exit of a ...
Raoul, Zana +2 more
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The Journal of Physical Chemistry B, 2006
The acid effect on the aggregation of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymers EO(20)PO(70)EO(20) has been investigated by transmission electron microscopy (TEM), particle size analyzer (PSA), Fourier transformed infrared, and fluorescence spectroscopy.
Bin, Yang +7 more
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The acid effect on the aggregation of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymers EO(20)PO(70)EO(20) has been investigated by transmission electron microscopy (TEM), particle size analyzer (PSA), Fourier transformed infrared, and fluorescence spectroscopy.
Bin, Yang +7 more
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Polymer, 1998
Abstract Temperature-sensitive polyurethanes are obtained by reacting trifunctional isocyanate with poly(ethylene oxide)– b -poly(propylene oxide)– b -poly(ethylene oxide) [Pluronic L122]. The temperature-dependent interactions among poly(propylene oxide) [PPO] segments are observed by n.m.r.
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Abstract Temperature-sensitive polyurethanes are obtained by reacting trifunctional isocyanate with poly(ethylene oxide)– b -poly(propylene oxide)– b -poly(ethylene oxide) [Pluronic L122]. The temperature-dependent interactions among poly(propylene oxide) [PPO] segments are observed by n.m.r.
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