Branched polyethers

The first attempt to construct a dendrimer with an electroactive Ru-polypyridi-ne core was based on the reaction of Ru(bpy)2Cl2 with a branched polyether-substituted phenanthroline ligand (11) [27]. In the potential window +2/-2V, this compound shows a one-electron oxidation process and three distinct one-electron reduction processes that, by comparison with the behavior of the... 

One of the first examples of this type of blend was composed of SPEEK or SPES as the acidic component and diaminated PES, poly(4-vinylpyridine) (P4VP), poly(benzimidazole) (PBl), or poly(ethyleneimine) (PEI) as the basic component. " For blend lEC values of 1.0 meq/g, conductivity values were reported to be good, as was H2/O2 EC performance. Thermal stabilities for these blends was also demonstrated to be high (>270°C). Other examples of acid-base PEMs include blends of SPPO and PBI, sulfonated poly(phthalazinone ether ketone) and aminated SPES, SPIs and aminated Pls, and SPEEK with PES bearing benzimidazole side groups, ° as well as an unusual example in which the blend is composed of sulfonated, hyper-branched polyether and pyridine-functionalized polysulfone. ... 

For thermoset materials, reactive polymers such as polyesters or polybutadiene derivatives combined with curing agents (e.g. isocyanates) are utilized. For thermoplasts one uses long-chained, partially branched polyether (Movital) or polymeric flouridated hydrocarbons (Fluorel). An example of a gelatin binder type is celluloseacetobutyrat (CAB), which is normally used in combination with nitrocellulose. 

From Table X, the IPDI based oligomers have better solvent resistance than the TDl based ones. IFDl based oligomers also appear to exhibit better adhesion. Other properties are not affected by dllsocyanate choice. Polyester based materials seem to give better flexibility and solvent resistance than polyether based urethanes (Table XI). The branched polyether in composition N gives better adhesion and solvent resistance than the linear polyether. 

We discuss now the case of branched polyethers such as resulting from trimethylol-propane with a functionality of 3, but in general /. There is an easy way to verify... 

A comparison of the branched polyether in panel J with the straight chain polyether with two more additional repeat units in panel K suggests that there is no difference in the spectra of the branch and straight chain... 

Chem. Descrip. Branched polyether polyurethane aq. disp. 

Wendland and Zimmerman [31] had remarked in their 1999 paper that what they referred to as cored dendrimers represented a system closely analogous to polymer imprinting, but within the framework of adiscrete single molecule. In their approach, a dendrimer is prepared by the assembly of branched polyether dendrons , around a central core by esterification. The periphery of the dendrimer is fully substituted... 

MD simulations of comb-branch polyethers of the structure shown in Fig. 7.14 (PEPE5) have been performed [60]. SPEs formed from this comb-branch polymer have also been studied experimentally [70-72]. A comparison of the ionic conductivity of SPEs with LiTFSI and this comb-branch polymer from simulation and experiment, along with the conductivity of a linear PEO SPE with same salt concentration is shown in Fig. 7.14 [60]. Good agreement between experiment and simulation is apparent. Furthermore, the conductivity of the comb-branch SPE is very similar to that of the linear PEO SPE. The slightly higher conductivity in the linear PEO SPE is facilitated by the lower molecular weight (2,380 Da) of the linear polymer compared to the comb-branch (around 6,000 Da). 

Hayamizu K, Aihara Y, Price W (2001) NMR and ion conductivity studies on cross-linked polv(ethyleneoxide-propyleneoxide) and branched polyether doped with LiN(S02CF3)(2). Electrochim Acta 46( 10-11) 1475-1485... 

Primary linear-alkyl monoalcohols + Branched polyethers... 

Synthetic ionophore ligands, mostly based on cyclic and branched polyethers, have been widely used in the last decade to study carrier facilitated cation transport across membranes. It has recently been observed that the organometallic ligand (C H )Co[P0(0C2H )2]2 Iso has... 

Synthesis of highly branched polyethers by cationic polymerization of hydroxymethyl-substituted oxetanes is a relatively... 

GC alone can be a valuable monomer for the synthesis of hyperbranched poly(hydroxyether)s (Scheme 25). In case of polymerization, GC, containing a l,3-dioxolan-2-one ring and hydroxyl group in a single molecule, is considered a latent cyclic AB2-type monomer. The anionic ROP of the GC, which proceeds with CO2 liberation, leads to a branched polyether. l,l,l-Tris(hydroxymethyl)propane or other multihydroxyl molecules are usually used as a initiator-starter and central core of the polyether. The hyperbranched polyglycerol structure is obtained by slow addition of the cyclic carbonate monomer at above 150 °C. Such polymers are characterized by a flexible polyether core and a multihydroxyl outer sphere. They are suitable for preparation of acrylic resins for dental applications or additives for polyurethane foams. Hyperbranched poly (hydroxyether)s from biscyclic carbonate with phenol group (2, Scheme 24) were also reported. 

Other polyesters that have been studied include hydroxy branched polyethers [20], methacrylic trimers [9], bntyl acrylate, methylmethacrylate and polyesters [21], and diol-dicarboxylic acid polyesters [22]. 

Branched PEE [106,107] and ABA-type triblock copolymers [102] were also synthesized. Polyalcohols (butanetriol, pentaerythritol), aliphatic polyacids and branched polyether polyols are used as branching agents [108-111]. 

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