Diisobutylene

Diisobutylene reacts with diphenylamine to produce octylated diphenylamine antioxidant for rubber. 

Diisobutylene reacts with phenol to produce para-f-octylphenol, used to synthesize phenolic rubber tackifying resins. 

Diisobutylene is used to produce surfactants and lubricant additives. 

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Sulfonated styrene—divinylbensene cross-linked polymers have been appHed in many of the previously mentioned reactions and also in the acylation of thiophene with acetic anhydride and acetyl chloride (209). Resins of this type (Dowex 50, Amherljte IR-112, and Permutit Q) are particularly effective catalysts in the alkylation of phenols with olefins (such as propylene, isobutylene, diisobutylene), alkyl haUdes, and alcohols (210) (see Ion exchange). Superacids. 

Most of the surface sizes used in North America are modified styrene maleic anhydride (SMA) copolymers. Commercially available materials include Scripset (Monsanto/Hercules Inc.), Cypres (Cytec), Sursize (Akzo Nobel), MSA (Morton), NovaCote (Georgia Pacific), and HTl (Hopton Technologies). Styrene acrylate emulsions that are commonly used include Jetsize and Unibond (Akzo Nobel), Basoplast (BASF), and Cypres (Cytec). Other materials used as surface sizes include acrylonitrile acrylate copolymer (Basoplast, BASF), stearylated melamine resin (Sequapel, Sequa), polyurethane (Graphsize, Vining Chemicals), and diisobutylene maleic anhydride copolymers (Baysynthol, Bayer). 

Di- and Triisobutylcncs. Diisobutylene [18923-87-0] and tnisobutylenes are prepared by heating the sulfuric acid extract of isobutylene from a separation process to about 90°C. A 90% yield containing 80% dimers and 20% trimers results. Use centers on the dimer, CgH, a mixture of 2,4,4-trimethylpentene-1 and -2. Most of the dimer-trimer mixture is added to the gasoline pool as an octane improver. The balance is used for alkylation of phenols to yield octylphenol, which in turn is ethoxylated or condensed with formaldehyde. The water-soluble ethoxylated phenols are used as surface-active agents in textiles, paints, caulks, and sealants (see Alkylphenols). 

Neopentanoic acid has also been produced commercially from diisobutylene [18923-87-0], in which the first step in the reaction sequence is a cracking or depolymeri2ation of the olefin to give isobutylene. 

The relationship between intrinsic viscosity [Tj] and mol wt for isobutylene polymers in diisobutylene is (79) ... 

The aqueous layer now contains approximately 8% hydrogen peroxide. This layer may be reused by adjusting the hydrogen peroxide percentage to 12.5 by use of either 30% or 50% hydrogen peroxide. The sulfuric acid must be readjusted to 40%. Approximately 1.9 kg. of aqueous layer is required for 2 moles of diisobutylene. 

The preparation of neopentyl alcohol from diisobutylene herein described represents an example of acid-catalyzed addition of hydrogen peroxide to a branched olefin, followed by an acid-catalyzed rearrangement of the tertiary hydroperoxide formed. In addition to neopentyl alcohol, there are formed acetone and also small amounts of methanol and methyl neopentyl ketone by an alternative rearrangement of the hydroperoxide. 

This process produces polymer gasoline with a high octane. Dimerization was first used (1935) to dimerize isobutylene to diisobutylene, constituted of 2,4,4-trimethyl-1-pentene (80%) and 2,4,4-trimethyl-2-pentene (20%). Both phosphoric and sulfuric acid were used as catalysts. 

Isobutylene (CH2=C(CH3)2) is a reactive C4 olefin. Until recently, almost all isobutylene was obtained as a by-product with other C4 hydrocarbons from different cracking processes. It was mainly used to produce alkylates for the gasoline pool. A small portion was used to produce chemicals such as isoprene and diisobutylene. However, increasing demand for oxygenates from isobutylene has called for other sources. 

Isobutylene could be dimerized in the presence of an acid catalyst to diisobutylene. The product is a mixture of diisobutylene isomers, which are used as alkylating agents in the plasticizer industry and as a lube oil additive (dimerization of olefins is noted in Chapter 3). 

Viscosity average molecular weights Mv were determined using a Ubbelohde viscometer and diisobutylene solutions at 20 °C with at least three dilutions for every solution. The Mv was calculated from intrinsic viscosity28. Averages of two determinations are reported. Reproducibility was 10%. 

Fig. 50.—Intrinsic viscosity-molecular weight relationship for polyisobutylene in diisobutylene (DIB) at 20° and in cyclohexane at 30°C. Open circles from Ref. 7 filled circles, Ref. 8.

Fig. 143.—The intrinsic viscosity of a polyisobutylene fraction of high molecular weight plotted against temperature in four solvents cyclohexane, diisobutylene (DIB), toluene and benzene. The lines shown have been calculated according to theory. (Fox and Flory. )...

Purification of industrial oils, kerosene/jet fuel, lubricating oils Mono- dicumyldiphenylamine Mono- dioctyldiphenylamine Dimer fatty acids Purification of xylenes Improvement of bromine number of recycle cumene in phenol plants Improvement of bromine number of recycle ethylbenzene in styrene plants based on liquid pha.se oxidation Alkylation of xylenes with diisobutylenes to mono-/ rr-butyI derivatives Phenyl xylyl ethane... 

However, when a less active olefin (e.g., diisobutylene or cyclohexene) or a liganded system (Bu3P/Co = 2/1,80 atm CO/H2, 190°C) was used, the hydrido species, e.g., HCo(CO)3PBu3, predominated throughout the reaction. The author concluded that in slower systems, initial interaction of the olefin with the hydrido species HCo(CO)3L could be the ratedetermining step. These results are complementary to those discussed (vide supra) for the rhodium carbonyl catalysis. 

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