Alkyl ether-substituted polymers

The first alkyl side-chain ether-substituted polysilane to be prepared was 40, with a single oxygen atom in one of the side chains. The polymer is soluble in alcohols, including methanol, in addition to common non-polar organic solvents.144 145... 

By modifying the functional groups they can be used,for example, as crosslinkers in high solid or powder coatings and in thermosets. Because of their good miscibility and low melt viscosity, they find applications as melt modifiers and as blend components. Modified hyperbranched polymers, like alkyl chain substituted poiy(ether)s and po-ly(ester)s sometimes exhibit amphiphilic behavior.They can, therefore, be used as carriers for smaller molecules,for example, dyestuff into polypropylene. 

Vinyl indoles, which bear structural similarities to vinyl carbazole, tend to form cyclic dimers through ring substitution at the 3-position. When this position is blocked by an alkyl group, linear polymers are formed. Difunctional monomers incorporating a p-methoxystyryl group and allyl or propargyl ether functions have been synthesized for use as photo cross-linkable compounds.These monomers were found to oxidize when exposed to the atmosphere. 

Borman nitrated PPO to give 11 that has a nitro-substituent on the polymer backbone. This material was then reduced to the amino-substitued polymer 12 that was then converted to the diazonium salt. (Scheme 4) The latter reacted with (3-naphthol to give an orange colored polymeric dye. The amino-substituted polymers 12 were reacted with dianhydrides or diglycidyl ethers to give cross-linked products." Alkylation of 12 with dimethyl sulfate gave the dimethyl derivative. 

The soluble polymer support was dissolved in dichloromethane and treated with 3 equivalents of chloroacetyl chloride for 10 min under microwave irradiation. The subsequent nucleophilic substitution utilizing 4 equivalents of various primary amines was carried out in N,N-dimethylformamide as solvent. The resulting PEG-bound amines were reacted with 3 equivalents of aryl or alkyl isothiocyanates in dichloromethane to furnish the polymer-bound urea derivatives after 5 min of micro-wave irradiation (Scheme 7.75). After each step, the intermediates were purified by simple precipitation with diethyl ether and filtration, so as to remove by-products and unreacted substrates. Finally, traceless release of the desired compounds by cyclative cleavage was achieved under mild basic conditions within 5 min of micro-wave irradiation. The 1,3-disubstituted hydantoins were obtained in varying yields but high purity. 

These considerations sparked our investigation into the possibility of producing responsive polymer gels from cellulose ether polymers. Cellulose ethers are alkyl-substituted cellulose derivatives which are on the FDA s GRAS list for use in food and pharmaceutical formulations. Since most cellulose ethers display lower critical solution temperatures (LCST), as gels they should be temperature... 

The chemistry of O-alkyl derivatives of lactams (lactim ethers) is one of the least studied aspects of lactam chemistry. The lactams themselves have been much investigated in the preparation of polymers, in connection with penicillin (/3-lactams),1 and also because of the tendency of certain substituted derivatives to ring-close to cyclols, cylopeptides, or cyclodepsipeptides.2,3 A review on lactams has appeared.4... 

The 1 1 adducts of various carboxylic acids and styrene, vinyl ethers, and isobutene have been isolated and used as initiators in the presence of Lewis acid activators. The polymerization rates correlate with the basicity of the leaving groups. However, isobutene polymerizes =103 times slower when initiated by pivalates and isobutyrates in the presence of BC13 than when initiated by acetates, even though they have similar pKa values [106]. Coordination of the covalent adducts with BC13 is evidently hindered when the alkyl substituents are bulkier. More detailed studies on vinyl ether polymerizations using a series of substituted benzoates demonstrate that the pKa values of the parent acid affects both the initiation rate and dynamics of ionization, and therefore the ability to prepare well-defined polymers [107]. 

Plourde [17] has described the radical addition of alkyl, substituted alkyl and benzyl thiols to polymer-supported cychtol allyl ethers. Treatment of immobilized allyl ether 117 with benzyl thiol in the presence of AIBN provided, after base-induced cleavage from the support and purification, sulfide 119 in high yield and purity (Scheme 25). Similar reactions with hydroxyl- and carboxyl-substituted alkyl thiols also resulted in good yields of products as single regioisomers [17]. 

Although the hydrolysis of alkyl halides to alcohols has been extensively investigated, an alternative two-step sequence involving substitution with carboxylate ion is more practical for the preparation of alcohols. Activation of the carboxylate anion prepared by the reaction of the acid with a base can be achieved (i) by use of a polar aprotic solvent and (ii) by use of aprotic apolar solvents under phase transfer catalysis, polymer conditions, or with crown ethers. 

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