Oxidation polyisobutene

The proportions of the different kinds of initial groups depend on the nature and rate of the different transfer reactions by which they are formed and the proportion of initial groups derived from the catalyst will depend on the ratio of the rate of initiation to the sum of the rates of the transfer reactions. Finally, although the main chain of the polyisobutene molecule is very resistant to chemical attack [14], by virtue of its chemical structure and configuration, the end-groups are readily attacked by atmospheric oxidation. 

It should be recalled that various other two-step macromonomer synthesis have been developed using the inifer technique as an adequate functionalization method for preparing the precursor. Thus, starting from to-chloro-polyisobutene, the de-hydrohalogenation can be followed by hydroboration and selective oxidation to yield almost quantitatively the -hydroxy precursor 78) ... 

Poloxamer 122 Poloxamer 123 Poloxamer 181 Poloxamer 182 Poloxamer 183 Poloxamer 212 Poloxamer 215 Poloxamer 217 Poloxamer 237 Poloxamer 284 Poloxamer 338 Poloxamer 407 Polyamide Polycarbonate Polyethylene Polyethylene, oxidized Polyisobutene Polypropylene Polystyrene Polyvinyl acetate Polyvinyl alcohol Polyvinyl chloride Polyvinyl stearate Potassium castorate Potassium cocoate... 

Polyacrylamidomethylpropane sulfonic acid Polyacrylic acid Polybutylene terephthalate Polydimethylaminoethyl methacrylate Polyester resin, thermoplastic Polyethylacrylate Polyethylene Polyethylene terephthalate Polyglucuronic acid Polyisobutene Polymethacrylamidopropyl trimonium chloride Polymethyl acrylate Polymethyl methacrylate Polyoxyisobutylene/methylene urea copolymer Polypropylene Polypropylene, oxidized Polyquaternium-1 Polyquaternium-2 Polyquaternium-4 Polyquaternium-5 Polyquaternium-6 Polyquaternium-7... 

Polyethylene Polyethylene, oxidized Polyglyceryl-10 tetraoleate Polyisobutene Polymethacrylic acid Polymethyl methacrylate Polypropylene Polysorbate 81 Polyvinyl alcohol Polyvinyl butyral... 

Water soluble polymers such as poly(ethylene oxide) or poly(acrylamide) and oleo-soluble polyisobutene were proved to be extremely efficient compounds in the reduction of turbulent friction. The same effect was reported in the case of the polymer compound extracted from Cyamopsis and Xanthamonas, trademark guar. 

The linear structure is an essential condition for the drag reduction efficiency, a maximal stretching of the macromolecular coil, for a given molecular weight, being required. Thus, the best results are obtained in the case of completely linear poly(ethylene oxide) and polyisobutene, followed by poly(acrylamide) [1080]. 

Polyisobutene -I- poly(propylene glycol) (oligomer mixtures) Poly(ethylene oxide) + poly(propylene oxide) (oligomer mixtures) Poly(propylene glycol -f poly(dimethyl siloxane) (oligomer mixtures)... 

Using allyl bromide as a model system it was found that on reaction with zinc oxide in a polyisobutene medium at usual cure temperatures, no allyl bromide, which would be expected from the first mechanism, was detected. (Feniak et ai, 1974). The very good thermal stability is also consistent with carbon-carbon-links which would be produced by the second mechanism. 

Polyisobutene is non-crystalline when unstretched and is therefore soluble at room temperature in hydrocarbons and halogenated hydrocarbons. The material is resistant to most acids, alkalis and aqueous solutions, as would be expected from its saturated hydrocarbon structure and absence of tertiary hydrogen atoms. The lack of tertiary hydrogen atoms renders polyisobutene more resistant to oxidation than polypropylene also, the less numerous and partially shielded methylene groups in polyisobutene are less reactive than those in polyethylene. However, polyisobutene is rather susceptible to thermal degradation since chain scission is favoured by the greater stability of the resultant tertiary free radical ... 

Adiabatic compressibility measurements have been performed on a number of polymer-solvent systems and have allowed indentification of specific interactions between polymer and solvent as in poly(ethylene oxide)-water or alcohol mixtures, effects of branching as in polyisobutene in hydrocarbon mixtures and helix-coil phenomena in polystyrene and polyether. ... 

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