Esters phthalate

Luks-Betlej et al. evaluated six different fiber materials for determination of seven different phthalates in water samples [56]. The tested phthalates included DMP, DEP, di-n-butyl phthalate (DBP), BBP, DEHP, di-n-octyl phthalate (DOP) and di-n-nonyl phthalate (DNP). All fibers investigated were favorable for the extraction of BBP. Low molecular weight phthalates (DMP, DEP, DBP) were best extracted by DVB/CAR/PDMS, DBP by CW/DVB and DEHP by PDMS fiber. CW/DVB fiber gave the best repeatability. Application of CW/DVB fibers to different water samples allowed the detection of 

Mori [20] has identified and determined very low levels of phthalate esters in river water using reversed phase high performance liquid chromatography using an ultraviolet detector. Phthalates were extracted with n-hexane and the rmcleaned or concentrated extracts were injected into three chromatographic systems, these being cross-linked porous beads (Shodex HP-225, Showa Penko Co.), porous polymer beads and 

An example of a chromatogram of the extract of a river water is shown in Fig. 4.3. The presence of M-dibutylphthalate and di-2-ethylhexyl-phthalate was observed. The concentrations of phthlates in the extract were 450ppb of n-dibutylphthalate and lOOppb of di-2-ethylhexyl-phthalate and their concentrations in river water were 45 and lOOppb, respectively. The first peak in Fig. 4.3 is contaminant(s) in n-hexane. 

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When blended with phthalate ester plasticizers, PVC becomes soft and pliable. 

Phtlialaldehydic acid Phthalated gelatin Phthalate esters Phthalate plasticizers Phthalates... 

TrioctylPhosphate. Trioctyl phosphate [1806-54-8/, C24H 04P, has been employed as a specialty flame-retardant plasticizer for vinyl compositions where low temperature flexibHity is critical, eg, in military tarpaulins. It can be included in blends along with general-purpose plasticizers (qv) such as phthalate esters to improve low temperature flexibHity. 

Raw Materials. PVC is inherently a hard and brittle material and very sensitive to heat it thus must be modified with a variety of plasticizers, stabilizers, and other processing aids to form heat-stable flexible or semiflexible products or with lesser amounts of these processing aids for the manufacture of rigid products (see Vinyl polymers, vinyl chloride polymers). Plasticizer levels used to produce the desired softness and flexibihty in a finished product vary between 25 parts per hundred (pph) parts of PVC for flooring products to about 80—100 pph for apparel products (245). Numerous plasticizers (qv) are commercially available for PVC, although dioctyl phthalate (DOP) is by far the most widely used in industrial appHcations due to its excellent properties and low cost. For example, phosphates provide improved flame resistance, adipate esters enhance low temperature flexibihty, polymeric plasticizers such as glycol adipates and azelates improve the migration resistance, and phthalate esters provide compatibiUty and flexibihty (245). 

Plasticizers. Monomeric (mol wt 250—450) plasticizers (qv) are predominantiy phthalate, adipate, sebacate, phosphate, or trimeUitate esters. Organic phthalate esters like dioctyl phthalate (DOP) are by far the most common plasticizers in flexible PVC. Phthalates are good general-purpose plasticizers which impart good physical and low temperature properties but lack permanence in hot or extractive service conditions and are therefore sometimes called migratory plasticizers. Polymeric plasticizers (mol wt up to 5000 or more) offer an improvement in nonmigratory permanence at a sacrifice in cost, low temperature properties, and processibiHty examples are ethylene vinyl acetate or nitrile polymers. 

Diperoxyketals, and many other organic peroxides, are acid-sensitive, therefore removal of all traces of the acid catalysts must be accompHshed before attempting distillations or kinetic decomposition studies. The low molecular weight diperoxyketals can decompose with explosive force and commercial formulations are available only as mineral spirits or phthalate ester solutions. 

Commodity Phthalate Esters. The family of phthalate esters are by far the most abundandy produced woddwide. Both orthophthaUc and terephthahc acid and anhydrides are manufactured. The plasticizer esters are produced from these materials by reaction with an appropriate alcohol (eq. 1) terephthalate esterification for plasticizers is performed more abundandy in the United States. Phthalate esters are manufactured from methanol (C ) up to Qyj alcohols, although phthalate use as PVC plasticizers is generally in the range to The lower molecular weight phthalates find use in nitrocellulose the higher phthalates as synthetic lubricants for the automotive industries. 

Di-2-EthylhexylPhthalate. In Western Europe, di-2-ethylhexyl phthalate [117-81-7] (DEHP), also known as dioctyl phthalate (DOP), accounts for about 50% of all plasticizer usage and as such is generally considered as the industry standard. The reason for this is that it is in the mid-range of plasticizer properties. DEHP (or DOP) is the phthalate ester of 2-ethyIhexanol, which is normally manufactured by the dimerization of butyraldehyde (eq. 2), the butyraldehyde itself being synthesized from propylene (see Butyraldehydes). 

Plasticizer Efficiency. This is a measure of the concentration of plasticizer required to impart a specified softness to PVC. Such a softness of material may be measured as a British Standard Softness (BSS) or a Shore hardness (Pig. 1). Por a given acid constituent of plasticizer ester, ie, phthalate, adipate, etc, plasticizer efficiency decreases as the carbon number of the alcohol chain increases, eg, for phthalate esters efficiency decreases in the order DBP > DIHP > DOP > DINP > DIDP > DTDP. An additional six parts per hundred in PVC of DIDP rather than DOP is required to give a hardness of Shore 80 when ah. other formulation ingredients remain constant. The consequence of this depends on the overall formulation and product costs. In addition to size of the carbon number of the alcohol chain, the amount of branching is also significant the more linear isomers are of greater efficiency. 

The reproductive toxicity of some phthalate esters has been reviewed by the Commission of the European Communities (45). This review concludes that testicular atrophy is the most sensitive indicator of reproductive impairment and that the rat is the most sensitive species. 

About one million tons of plasticizers aie used annually in Western Europe. Some 92% of this total is used to plasticize poly(vinyl chloride) (PVC) and about 95% of these PVC plasticizers are phthalate esters. In spite of the fact that there are several hundred plasticizers in commercial use in the world, only relatively few (ie, phthalates) are used in amounts that make them significant in toimage terms, and hence in their likely environmental input and impact. 

Semicommercial production of 3,3/4,4 -biphenyltetracarboxyhc dianhydride [2420-87-3] in the United States has been announced by Occidental Chemical Corp. (74). This polyimide resin intermediate is prepared by dehalogenative dimerization of 4-chlorophthalate salts (75) or by oxidative coupling of phthalate esters (76). 

Most carrier-active compounds ate based on aromatic chemicals with characteristic odor. An exception is the phthalate esters, which are often preferred when ambient odor is objectionable or residual odor on the fabric caimot be tolerated. The toxicity of carrier-active compounds and of their ultimate compositions varies with the chemical or chemicals involved. The environment surrounding the dyeing equipment where carriers are used should always be weU-ventilated, and operators should wear protective clothing (eg, mbber gloves, aprons, and safety glasses or face shields, and possibly an appropriate respirator). Specific handling information can be obtained from the suppHer or manufacturer. 

The phthalate esters are one of the most widely used classes of organic esters, and fortunately they exhibit low toxicity (82). Because of the ubiquitous nature of phthalates, many iavestigations have been conducted to determine their toxicides to marine life as well as ia mammals (83—85). Generally, phthalates are not absorbed through the skin and are not very potent when inhaled. The phthalates become less toxic as the alcohol group increases in molecular weight. For example, dimethyl phthalate has an oral LD q (mouse) of 7.2 g/kg, whereas di(2-ethylhexyl) phthalate shows an oral LD q (rat) of greater than 26 g/kg. 

Many materials used for food packaging contain chemicals which can migrate into the food in small quantities. These include plasticizers such as phthalate esters, used in wrapping materials, and bisphenol A, used in the resin linings of... 

In addition to their endocrine disrupting properties, it must be appreciated that many of the chemicals in question possess more general toxic properties, which may be potentiated by metabolism by the organism. Several PAHs, PCBs and PCDDs are carcinogenic, while certain phthalate esters can enhance the excretion of zinc, potentially leading to zinc deficiency. Zinc, an essential element, plays a vital role in spermatogenesis and mature T-cell production. Deficiency may result in abnormalities of the male reproductive system, depletion of spermatogenesis and suppression of the immune system. 

Other derivatives can be prepared by reaction of the alcohol with an acid anhydride. For example, phthalic or 3-nitrophthalic anhydride (I mol) and the alcohol (Imol) are refluxed for half to one hour in a non-hydroxylic solvent, e.g. toluene or alcohol-free chloroform, and then cooled. The phthalate ester crystallises out, is precipitated by the addition of low boiling petroleum ether or is isolated by ev toration of the solvent. It is recrystallised from water, 50% aqueous ethanol, toluene or low boiling petroleum ether. Such an ester has a characteristic melting point and the alcohol can be recovered by acid or alkaline hydrolysis. 

Methyl-2-pentanol [108-11-2] M 102.2, b 131-132", d 0.810, n 1.413. Washed with aqueous NaHC03, dried and distd. Further purified by conversion to the phthalate ester by adding 120mL of dry pyridine and 67g of phthalic anhydride per mole of alcohol, purifying the ester and steam distilling it in the presence of NaOH. The distillate was extracted with ether, and the extract was dried and fractionally distd. [Levine and Walti 7 Bio/ Chem 94 367 1931],... 

Developments in the USA have led to the availability of terephthalate plasticisers, for example dioctyl terephthalate (DOTP). Whilst these materials are very similar to the corresponding o-phthalate esters they are generally less volatile and are best compared with d-phthalates with one or more carbon atom in the alkyl chain. As with the linear dialkyl phthalates the terephthalates show good fogging resistance. This is a phenomenon in which new cars on storage fields awaiting delivery develop misting on the windows due, apparently, to the volatility of additives in PVC compounds used with the car. 

Butadiene and related compounds Dichloromethane Vmylidene chloride Phthalate esters... 

Plasticizers/oils. These are added for several reasons (a) to improve the compatibility between SBR and the other additives (b) as extender (to reduce cost) (c) to soften the SBR (d) to change the wetting properties. The most common additives are organic phosphates, phthalate esters and aromatic hydrocarbon oils. 

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