Aliphatic ester plasticizers

The bulk of aliphatic ester plasticizers are derived from adipic, sebacic and azelaic acid esterified with linear or branched monofunctional alcohols of short to medium-chain length, for example, dioctyl adipate (DOA, di[2-ethylhexyl]adipate), diiso-nonyl adipate (DINA), di[n-butyl]sebacate (DBS). Adipate, azelate and sebacate plasticizers are distinguished by their low viscosity, thus making them particularly attractive to the plastisol sector, and giving excellent low-temperature flexibility properties. 

For applications where it is important to have a compound with good low-temperature resistance, aliphatic ester plasticizers are of great value. Dibutyl sebacate, dioctyl sebacate, and, more commonly, cheaper esters of similar effect derived from mixed acids produced by the petrochemical industry are used. These plasticizers give PVC products with a cold flex temperature of — 42°C. 

The most common types of plasticizer are the phthalic acid esters of Cg, Cio alcohols citric acid esters and epoxy aliphatic esters. 

An electric conductive rubber base containing carbon black is laminated with an electric conductive cover layer of phosphoric acid ester plasticizer and other ionic surfactants to prepare antistatic mats, where the covers have colors other than black. It is also reported that alkyl acid phosphates act as color stabilizer for rubber. Small amounts of phosphate esters are helpful in restoring reclaimed rubber to a workable viscosity [284,290]. Esters of phosphoric acid are used in the production of UV-stable and flame-retarded alkylbenzenesulfonate copolymer compositions containing aliphatic resins and showing a high-impact strength... 

Because of the presence of the chlorine atom In every repeating unit PVC does not bum as readily as hope. When used as a plasticizer, tricresyl phosphate also contributes to flame retardancy. In contrast, the organic ester plasticizers, such as DOP, contribute to the combustibility of plasticized PVC Tricresyl phosphate is more toxic than organic esters, and DOP is more toxic than aliphatic esters, such as dioctyl adipate. 

Effect of Plasticizer Shape. Extended plasticizer molecules such as aliphatic chains with a high degree of flexibility, usually lower Tg or Tc much more than bulky plasticizer molecules, such as those containing ring structures. However, Table XIII shows that the comparison between aliphatic and aromatic ester plasticizers is also determined by the length of the alcohol residues and by separation between the ester groups. 

Chlorinated paraffins, which contain up to 60-70% chlorine, are low in cost and are used as secondary plasticizer in PVC wire and cable insulations. Perchlorobicyclopentadiene has little plasticizing action and is used in polyethylene. Some of the more expensive bromine-containing fire retardants which have been used in the ratio of 5 p.p.h. in polystyrene foam, may be reduced to 0.5 p.p.h. by adding synergists such as peroxides or nitroso compounds. The reaction-type retardants, such as chlorendic acid and anhydride, hydroxy-terminated phosphonated esters, and specific brominated aliphatic esters, are admixed to rigid and flexible polyurethane foams, reinforced polyesters, phenolics, and epoxy resins. 

Salmi, E.J., Leimu, R. (1947) The effect of structure on the rate of alkaline hydrolysis of aliphatic esters. Suonten Kemistiehti 20B, 43. Sanborn, J.R. et al. (1975) Plasticizers in the environment the fate of di-N-octylphthalate (DOP) in two model ecosystems and uptake and metabolism of DOP by aquatic organisms. Arch. Environ. Contam. Toxicol. 3(2), 244-255. 

It is often useful to employ so-called secondary plasticizers, which have limited compatibility with the host polymer. Thus, aliphatic diesters are poorly compatible with PVC, but they can be combined with the highly compatible phthalate ester plasticizers to improve low temperature properties of the blend. 

Hercolube [Aqualon], TM for synthetic lubricant base stocks. J15 Saturated aliphatic ester of pentaerythritol for plasticizing vinylidene chloride. 

It must be emphasized, however, that quite frequently no single plasticizer can satisfy all the above requirements or produce all the desired property enhancements. It is generally necessary to blend several plasticizers and compromise some properties, particularly those that are not critical to the specific application. For example, some applications require that DOP-plasticized PVC remains flexible at low temperatures. This requires further addition of DOP to the formulation to achieve the desired flexibility, but the additional DOP would adversely affect the hardness and performance of the product at ambient temperatures. Instead, aliphatic diesters such as DOA and DBS (dibutyl sebacate), which are more effective in enhancing low-temperature flexibility than DOA, are needed to improve low-temperature performance. However, the use of these esters is accompanied by unacceptable levels of volatility and oil extraction. Consequently, in such applications a combination of phthalate and aliphatic esters is required to produce the desired product even though some compromise in product performance will occur. 

Aliphatic esters are diesters of adipic, sebacic or azelaic acids and offer greater resistance to low temperatures than phthalates, but at a higher cost Epoxy ester plasticizers have limited compatibility with PVC so are used at low concentrations. The most widely used epoxy ester plasticizer is epoxidized soya bean oil (ESBO). ESBO resists extraction, does not migrate readily and acts also as a heat stabilizer. Other plasticizers in this group include epoxidized linseed oil and tall oil. 

The most common example of this class of plasticizer are the adipate esters, although succinates, gluterates, azelates and sebacates are encountered. The synthesis of these esters is similar to that for phthalate esters. The most commonly employed aliphatic ester is di-2-ethylhexyl adipate (DOA), a very cost effective plasticizer. A comparison of selected performance properties of DOP, DOA and trioctyl trimellitate (TOTM), based on 2-ethyl hexanol, is given in Table 14 (49). 

Primary amides, calciiun stearate, ethylene bis-stearamide, erucamide, fluoropolymers and silicones can be employed in polymers other than PVC. PTFE can also be used in polyamide processing, improving the friction and wear properties of gears and other engineering components. ABS and SAN benefit from the addition of zinc stearate or a secondary bis-amide, sometimes in combination with glyceryl monostearate or a fatty acid amine. Engineering plastics can be lubricated by secondary amides, aliphatic esters such as palmitates and sebacates, and silicones. 

Plasticizers are compounds added to polymers to facilitate processing and to increase the flexibility and toughness of the final product. The plasticizer reduces the intermolecular attractions between polymer chains. The overwhelming majority of applications impart flexibihty to PVC. The most common plasticizers are aliphatic esters of various carboxylic acids or aromatic esters of phosphoric acid. 

Aromatic esters are more resistant. Resistance to microbial attack among phthalate plasticizers follows resistance to hydrolysis—that is, essentially to heat stability. Aliphatic phosphate plasticizers are similar in microbial resistance to phthalates aromatic and halogenated phosphates and chlorinated paraffin appear to be inedible. Usually, plasticizer choice is dictated by other factors, thus requiring use of biocides. 

Formulating for low SIC and PF commonly involves choice of ester plasticizers having substantial aliphatic hydrocarbon side chains, use of hydrocarbon secondary plasticizers, use of calcined clay filler, reduction generally of polar additives, and (unfortunately) use of lead-based stabilizers. 

Uses Emulsifier, wetting agent, plasticizer for industrial applies. plasticizer for wax paper adhesives solvent for PVAc thickener for PVAc emulsions coalescing agent for resin particles in air-drying of resin film Properties Pale yel. liq. sol. in water, ether, alcohol, ketone, lower aliphatic ester, and aromatic hydrocarbon solv. sp.gr. 1.1 vise. = 50 cps HLB14 acid no. 2 max. flash pt. > 300 F ref. index 1.502 pH 4-6 (50% aq.)... 

AplP ratio. The Ap/ P ratio is calculated by dividing the numbers of carbon atoms in aliphatic chains in a plasticizer molecule by the number of ester groups present. The Ap/P ratio correlates well with several properties of the plasticizers such as melting point, density, modulus and water absorption. 

P.Y.191 displays excellent solvent fastness in aliphatic and in aromatic hydrocarbons, as well as in the commonly used plasticizers. The pigment is almost completely fast to alcohols and esters but not to water, ketones and methylglycol. 

P.V.23, also referred to as Carbazole Violet, is a universally useful product. Its color, a bluish violet shade, is not accessible with other Pigments. P.V.23 is used in almost all media which are typically colored with pigments. The list of suitable systems ranges from coatings and paints to plastics, printing inks, and other special-purpose media. P.V.23 is entirely fast to many organic solvents. At standardized conditions (Sec. 1.6.2.1), it is fast to alcohols, esters, and aliphatic hydrocarbons as well as to plasticizers such as dibutyl and dioctyl phthalate. Other solvents, such as ketones, are colored slightly (step 4). 

Jackson, Jr, W. J. and Morris, J. C., Poly esters of 4,4 -biphenyl dicarboxylic acid and aliphatic glycols for high-performance plastics, in Liquid Crystalline Polymers, ACS Symposium Series, Vol. 453, American Chemical Society, Washington, DC, 1990, pp. 16-32. 

There are several plasticizers for PVC that may be used in propellants. Weil (19) mentions sebacates, phthalates, adipates, and glycol esters of higher fatty acids as being desirable. Dibutyl sebacate, dioctyl sebacate, and 2-ethylhexyl adipate are all good. The plasticizer has a most important effect on the physical properties of the cured propellant and the variation of these properties with temperature. Long chain, aliphatic plasticizers impart improved low temperature flexibility, and hence are preferable to aromatic plasticizers such as the phthalates. An increase in plasticizer viscosity leads to an increase in viscosity of the mixed pro-... 

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