Alkyl phthalate

If the perfectly anhydrous alcohols are required, the redistilled alcohol may be treated with the appropriate alkyl phthalate or succinate as already detaUed under Ethyl alcohol (5). 

Isobutyl alcohol (2-metbyl-l-propanol) [78-83-1] M 74.1, b 108 /760mm, d 0.801, n 1.396. Dried with K2CO3, CaS04 or CaCl2, filtered and fractionally distd. For further drying, the redistd alcohol can be refluxed with the appropriate alkyl phthalate or succinate as described under ethanol (see also p. 271). 

Plasticizers can be classified according to their chemical nature. The most important classes of plasticizers used in rubber adhesives are phthalates, polymeric plasticizers, and esters. The group phthalate plasticizers constitutes the biggest and most widely used plasticizers. The linear alkyl phthalates impart improved low-temperature performance and have reduced volatility. Most of the polymeric plasticizers are saturated polyesters obtained by reaction of a diol with a dicarboxylic acid. The most common diols are propanediol, 1,3- and 1,4-butanediol, and 1,6-hexanediol. Adipic, phthalic and sebacic acids are common carboxylic acids used in the manufacture of polymeric plasticizers. Some poly-hydroxybutyrates are used in rubber adhesive formulations. Both the molecular weight and the chemical nature determine the performance of the polymeric plasticizers. Increasing the molecular weight reduces the volatility of the plasticizer but reduces the plasticizing efficiency and low-temperature properties. Typical esters used as plasticizers are n-butyl acetate and cellulose acetobutyrate. 

Foster PM, Thomas LV, Cook MW, et al. 1980. Study of the testicular effects and changes in zinc excretion produced by some n-alkyl phthalates in the rat. Toxicol Appl Pharmacol 54 392-398. 

Urushigawa Y, Yonezawa Y. 1979. Chemico-biological interactions in biological purification systems VI. Relation between biodegradation rate constants of di-n-alkyl phthalate esters and their retention times in reverse phase partition chromatography. Chemosphere 5 317-320. 

Caldwell, D.J. 1999. Review of mononuclear cell leukemia in F-344 rat bioassays and its significance to human cancer risk A case study using alkyl phthalates. Regul. Toxicol. Pharmacol. 30 45-53. 

Gelatinizzahti (Gelatinizers). Belgrano (Ref 31, pp 218—19) lists Centralites, phthalides, alkyl-phthalates (such as ethyl butyl), diphenyl-urethane and ethylphenylurethane... 

Since cellulose nitrate is intractable, in 1870 John W. Hyatt added camphor as a plasticizer to flexibilize this plastic. Some 60 years later, Waldo Semon used tricresyl phosphate as a plasticizer for PVC. Dialkyl phthalates, such as dioctyl phthalate (DOP) and other alkyl phthalates which replaced the more toxic tricresyl phosphate, are now used as plasticizers primarily for PVC at an annual rate of 1 million tons. 

Caustic soda solution (3) Caustic soda solution (3) Caustic soda solution (3) Caustic soda solution (3) Caustic soda solution (3) Diisodecyl phthalate (13) Di-nonnal-alkyl phthalate (13) Dioctyl phthalate (13) Ethyl acetate (13) Ethylene dichloride (5)... 

Isoamyl alcohol [123-51-3] M 88.2, b 132 /760mm, d 0.809, n 1.408. Dried with K2C03 or CaS04, then fractionally distd. If more nearly anhydrous alcohol is required, the distillate can be refluxed with the appropriate alkyl phthalate or succinate as described for ethanol. 

The procedure usually is unsuitable for tertiary alcohols since the reaction with phthalic anhydride or succinic anhydride either fails or results in dehydration of the alcohol. A few tertiary alkyl phthalates, however, have been prepared and resolved by first converting the alcohols to sodium or potassium salts and allowing these to react79 80 with phthalic anhydride. This modification has been applied successfully to dUa- and /S-santalols81 and cB-linalool.81 As already mentioned, glycols cannot be resolved by this procedure because they form polymeric esters when heated with phthalic or succinic anhydride. Phenols also usually form phthaleins or other condensation products instead of simple acid esters. 

The data support specifically the use of epoxy-containing plasticizers in all systems for exterior exposure. Performance is enhanced by using n-alkyl phthalates and 2-ethylhexyl analogs as opposed to plasticizers derived from oxo-alcohols. 

The hydrolysis of the active alkyl phthalates is usually carried out by dissolving them in a 20-25% aqueous solution of sodium hydroxide containing 2.5 moles of alkali and distilling the mixture with steam. Filtration or extraction of the alcohol may be necessary when it is not volatile with steam. No evidence of racemization has been observed with various types of saturated alcohols even on prolonged boiling with concentrated aqueous alkali. Certain alcohols of the allylic type or alcohols otherwise sensitive to alkali or to heating may require more cautious treatment, both in the hydrolysis and in the subsequent final purification. Should the alcohol be foimd to be optically impure at this stage it sometimes may be purified by recrystallization. Either the... 

Polyvinyl Chloride (PVQ Foams. Rigid PVC foam is inherently fire retardant because of the high chlorine content (56.7%). Flexible PVC foams present increased fire hazards because of the plasticizers they contain. Flammable plasticizers used include alkyl phthalates, as dioctyl phthalate. Non-burning types include alkyl aryl phosphates (phosphate esters). The latter types should improve resistance to ignition and reduce flame spread when compared to the usual phthalate plasticizers (38) (41). 

Chemical/Pharmaceutical/Other Class Alkyl phthalate... 

Interaction characteristics in polymer-related areas frequently make use of solubility parameters (16). While the usefulness of solubility parameters is undeniable, there exists the limitation that they need to be estimated either by calculation or from indirect experimental measurements. The thermodynamic basis of IGC serves a most useful purpose in this respect by making possible a direct experimental determination of the solubility parameter and its dependence on temperature and composition variables. Price (17) uses IGC for the measurement of accurate % values for macromolecule/vapor pairs, which are then used for the evaluation of solubility parameters for a series of non-volatile hydrocarbons, alkyl phthalates, and pyrrolidones. It may be argued that IGC is the only unequivocal, experimental route to polymer solubility parameters, and that its application in this regard may further enhance the practical value of that parameter. Guillet (9) also notes the value of IGC in this regard. 

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