Homopolymeric poly ethers

As depicted in Scheme 2, homopolymerization of 1 to form the aromatic poly(aryl ether) 6FNE utilized the Scholl reaction in nitrobenzene with anhydrous ferric chloride at room temperature. A 100-ml round-bottom flask was charged... 

Polyether Polyols. Polyether polyols are addition products derived from cyclic ethers (Table 4). The alkylene oxide polymerization is usually initiated by alkali hydroxides, especially potassium hydroxide. In the base-catalyzed polymerization of propylene oxide, some rearrangement occurs to give allyl alcohol. Further reaction of allyl alcohol with propylene oxide produces a monofunctional alcohol. Therefore, polyether polyols derived from propylene oxide are not truly difunctional. By using zinc hexacyano cobaltate as catalyst, a more difunctional polyol is obtained (20). Olin has introduced the difunctional polyether polyols under the trade name POLY-L. Trichlorobutylene oxide-derived polyether polyols are useful as reactive fire retardants. Poly(tetramethylene glycol) (PTMG) is produced in the acid-catalyzed homopolymerization of tetrahydrofuran. Copolymers derived from tetrahydrofiiran and ethylene oxide are also produced. 

Enzymatic ROP of 2-oxo-12-crown-4-ether (OC) was studied by Meijer and coworkers [106], OC is different from other ether containing lactone monomers previously studied as it combines high hydrophilicity with a large ring size. Using Novozym 435 as catalyst, at 60°C for 90min in a mixture of toluene and tri-t-butylbenzene, homopolymerization of OC was successfully accomplished giving poly(OC) in yields >95% with M and Mw/M values of 3400 and 2.1, respectively. 

Solvents influence the rate of free-radical homopolymerization of acrylic acid and its copolymerization with other monomers. Hydrogen-bonding solvents slow down the reaction rates. Due to the electron-withdrawing nature of the ester groups, acrylic and methacrylic ester polymerize by anionic but not by cationic mechanisms. Lithium alkyls are very effective initiators of a-methyl methacrylate polymerization yielding stereospecific polymers.Isotactic poly(methyl methacrylate) forms in hydrocarbon solvents. Block copolymers of isotactic and syndiotactic poly(methyl methacrylate) form in solvents of medium polarity. Syndiotactic polymers form in polar solvents, like ethylene glycol dimethyl ether, or pyridine. This solvent influence is related to Lewis basicity in the following order ... 

Carboxylated PAES can be synthesized by sequential lithiation and carboxylation of poly(arylene ether sulfone) in tetrahydrofuran. The carboxyl groups are then converted into acid chloride groups by thionyl chloride and treatment with V-oxypyridine-2-thione gives the thiohydroxamic ester [60], A grafting reaction is obtained by adding to the polymer styrene and irradiation. Homopolymerization of the styrene does not take place under these conditions. Other vinyl monomers, including methyl methacrylate and acryl-... 

It so happens that there is a way to exert FRRPP-based control over statistical copolymerizations/multipolymerizations early in the propagation reaction, and then continue chain extension after one of the monomers has been exhausted without having to alter reactor conditions. This is very attractive, because alteration of reactor conditions requires additional reaction time and steps and may even involve the use of extra equipment. For the S/AA copolymerization with excess S in the monomer eharge, ether is used as solvent/precipitant to facilitate FRRPP homopolymerization of styrene. However, we have established that poly(acrylic acid) precipitates in ether... 

In the macromonomer approach, polymeric chains (of monomer Mi) end-functionalized with a vinyl group are homopolymerized (with Mi) or copolymerized (with M2) to produce branched (co)polymers. Thus, poly(ethylene glycol) methyl ether methacrylate (CJien et al., 2003) and poly(dimethyl siloxane) methacrylate (Shinoda and Matyjaszewski, 2001) have been homo- or copolymerized to yield graft (co) polymers with the corresponding pendant chain. 

Homopolymerization of styrene polystyrene PS Mixing with butadiene rubber (SBR) increasing impact strength (high impact PS or PS-HI) Mixing with poly(phenylene ether) (S/PPE) increasing temperature stability ... 

Using a Caldum-amide initiating system, novel high-MW PEO-btocfe-poly(alkyl glycidyl ether) diblock copolymers with enhanced association properties in aqueous media were prepared. The copolymers were synthesized via sequential suspension polymerization of epoxide monomers. The hydro-phobic block was formed by the polymerization of monomers with a general sttucture shown in Figure 7, followed by EO polymerization. The homopolymerization of hydrophobically modified glycidyl ethers proceeded only at elevated temperatures. 

A particularly important breakthrough was achieved by Bai and Jennings in 2005 in the surface-catalyzed polymerization of diazomethane by using ethyl diazoacetate (EDA) as a comonomer [30] (Scheme 8). Although surface-catalyzed homopolymerization of EDA did not proceed, EDA can be incorporated into the resulting polymer chain when an ether solution of a mixture of diazomethane and EDA was contacted with an Au-surface. The resulting surface bound copolymer, poly(methylene-co-ethoxycarbonylmethylene), has the same structure as that of random copolymer of ethylene and ethyl acrylate. Whereas the incorporation efficiency... 

We examined the homopolymerizations and copolymerizations of styrene (St), methyl methacrylate (MMA), acrylonitrile (AN), a functional styrene, i.e., p-aminostyrene (ASt), and functional methacrylates, i.e., 2-ethyhexyl (EHMA), benzyl (BzMA), phenyl (POMA), glycidyl (GMA), 2-hydroxyethyl (HEMA), poly(ethylene glycol) methyl ether (PEGMA), and A,A-dimethylaminoethyl (DMAEMA) methacrylates as well as methacrylic acid (MAA) (Figure 7.2), for example, by using several catalysts. The results will be summarized below. 

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