Plasticizer lower volatility

TrimeUitic anhydride is converted to PVC plasticizers, polyesters, water-soluble alkyd coatings, and polyamide—imide resias. The trimellitate plasticizers have a lower volatility than those derived from phthaUc anhydride (see Plasticizers). 

Results The data in Table II offer the opportunity to compare phthalates of four different eight-carbon alcohols. The performance differences are perhaps greater than would be expected from such simple variations in skeletal makeup. The most notable differences are in volatility and low temperature properties, but other minor differences also exist. Greater linearity leads to increased efficiency (as measured by the 100% modulus), lower volatility, better flexibility at low temperatures, and better resistance to soapy water. In most circumstances, the linear alcohol phthalates are quite similar to straight chain phthalates. This is to be expected in view of the close similarity of structures. (The true value of a plasticizer system must, of course, consider not only oerformance but price. Thus, high efficiency can sometimes be a disadvantage when costs on a pound volume basis are calculated. In other words, a less efficient plasticizer often gives the lowest compound pound volume cost.)... 

Plasticizers are organic liquids of high viscosity and low volatility. The esters of dicarboxylic acids (e.g., dioctyl phthalate) are well-known examples. Plasticizers lower the softening and film-forming temperatures of the binders. They also improve flow, flexibility, and adhesion properties. Chemically, plasticizers are largely inert and do not react with the binder components. Most binders used today are inherently flexible and can be regarded as internally plasticized resins. For this reason, use of plasticizers has declined. 

Figure 10.44 shows that the rate of stabilizer loss corresponds to molecular weight of plasticizer. Lower molecular weight plasticizers seem to have a steeper relationship than the less volatile plasticizers. 

This traditional plasticizer has been manufactured since 1930s under the trade name of Mesamoll. Only recently Mesamoll II having lower volatility and better fogging resistance was introduced. These are improved by replacement of substituent R with paraffin of a higher molecular weight. 

A wide range of azelates are available but di-(2-ethylhexyl) azelate is used in applications which require low temperature properties similar to those obtained with di-(2-eth-ylhexyl) adipate but with better retention of the plasticizer because of its lower volatility. 

Diisodecyl glutarate n. (CH2)3(COO 10 21)2- A plasticizer for PVC having low-temperature properties equal to those of dioctyl adipate but with lower volatility and greater resistance to soapy water. 

COOC9Hi9)2. a plasticizer for PVC, cel-lulosics, and polystyrene. It has lower volatility than dioctyl phthalate with equivalent low-temperature performance and poorer efficiency. 

Octyl benzyl phthalate (OBP) n. A plasticizer for PVC, cellulosics, polystyrene, and polyvinyl butyral. It is similar to butyl benzyl phthalate but has lower volatility. It resists oil extraction See image). 

The application fields of plasticisers range from automobiles and construction to toys and medical products. Phthalate plasticisers such as dibutyl phthalate and di(2-ethylhexyl) phthalate are widely used due to the higher plasticising efficiency and lower volatility of these phthalate plasticisers. Phthalate plasticisers are still widely used in the processing of flexible PVC [29]. However, recently, the use of phthalate plasticisers has been questioned due to their debatable toxicity in consumer products made of PVC matrices, especially in blood supply and similar medical plastics, because the content of... 

Plasticizers affect mechanical properties of the polymer [36]. They qualify as processing modifiers and lower polymer melt viscosity, even with addition of small amounts, and also migrate depending upon the molecular weight. Even though plasticizers are volatile in nature, they are very compatible. Usually additives are used in relatively small amounts. More addition of additive will cause undesirable effects in clarity due to accumulation on the surface of the film. 

As their name implies, plasticizers are additives that soften a material, enhancing its flexibility. The worldwide market for plasticizers is currently over five million metric tons, with over 90% used to soften PVC. The most common plasticizers are phthalates however, due to the relatively high vapor pressure of these compounds, plasticizers will evaporate from the polymer structure as evidenced by the new car smell of new cars, as well as the organic film that becomes deposited on the interior windshield surface. For these applications, it is best to use a plasticizer with a lower volatility such as trimellitates. 

The Tg of a polymer can be reduced by the addition of a plasticizer to the solid plastic. This reduces the van der Waals interactimi between the polymer chains and allows the molecules to move. The plasticizer may be considered as an internal lubricant. The plasticizer can also be cmisidered to increase the free volume of the polymer by allowing increased motion of the chain ends, the side chains, or even the main chain. Another possible mechanism by which the plasticizer lowers the is in terms of the solvent/ solute system that forms when the plasticizer can be considered to solubilize the polymer. The plasticizer is usually a low volatile, low molecular weight organic compound which is compatible with the polymer. 

Increasing the surface oxidation of the carbon lowers the electrical conductivity in plastics, assuming other properties are constant. For applications where conductivity is important, grades of carbon black with lower volatile content should be selected. 

Examples of common plasticizers include phthalate esters such as dioctyl phthalate (DOP), more properly called di-2-ethylhexyl phthalate (DEHP), and used as an inexpensive general purpose plasticizer. This is made by reacting phthahc anhydride with 2-ethylhexanol. Another example is diisodecyl phthalate (DIDP). DIDP has lower volatihty and improved resistance to soapy water extraction. It has many applications in PVC used for wire and cable coating. Phthalate plasticizers are also made from linear alcohols such as 1-hydroxyheptane, 1-hydroxynonane, and 1-hydroxyundecane. They are often used when superior low temperature properties, lower volatility, or outdoor weathering is required. 

Because of the lower volatility of DIDP and DPHP relative to other GP plasticizers, these two plasticizers are also sometimes considered low-volatility plasticizers. For automotive interior products the plasticizers DEHP, DINP, DEHTP, DC9CH, citrates, benzoates, as well as many of the phthalate alternatives would fail many interior emission or fogging requirements while DIDP and DPHP, along with trimellitate esters and the linear phthalates L9P and L91P, would pass. 

DIDP is sometimes used instead of a phthalate ester plasticizer such as DOP because it possesses a higher molecular weight and lower volatility and imparts greater permanence to the compound than DOP. On the other hand, DIDP has a somewhat different compatibility with some specialty elastomers and may not be as effective at improving the compound s low-temperature properties. 

The mechanical properties of vinyl compounds plasticized with Palatinol N are comparable to products plasticized with other diisononyl phthalates. The unique nature of this ester results in lower volatility, improved processibility and better low temperature performance. 

Also useful in aqueous eaulsion systens sucb as caulks and polyvinyl acetate adhesives. Uniplex 400 nay be used to formulate adhesives that need to provide good adhesion betwera porous and polyolefin surfaces. In caulk formulations, the sane excellent performance of other benzoate plasticizers can be elected in addition to providing lower volatility. 

Epoxy tallate esters are good low temperature plasticizers, comparable to DOA in effect, with lower volatility and migration characteristics. Blends of 25-30 percent EPT with low-temperature plasticizers have been common. Epoxy plasticizers in general have low fogging tendency. Automotive interior usage has centered on bisep-oxides because of their superior light resistance. 

Di-2-ethylhexyl Terephthalate (DOTP) and Di-2-ethylhexyl Isophthalate (DOIP) Although the chemical structures of these two aromatic esters are very similar to the phthalate ester DOP, these plasticizers differ slightly in performance properties. This is especially true with DOTP, which imparts better low-temperature properties, lower volatility, and lower plastisol viscosity versus DOP. However, it is less compatible, especially when secondary plasticizers are incorporated into the product. The plasticizing efficiency and volatility of DOTP are similar to those of DINP. DOTP finds some use especially in plastisol applications,... 

These products are formulated for optimum cost/performance characteristics for the specific use. The majority of these applications can utilize GP plasticizers such as DINP, DOP, or DOTP. Linear or straight-chain phthalates such as 71 IP-, L9P-, or 61 OP-type plasticizers, are used for improved low-temperature properties and improved oxidation resistance, while DIDP is used for lower volatility and improved diffusion resistance. For improved resistance to migration into nitrocellulose furniture finish, one may choose DOTP or a DIDP/hydrocarbon secondary plasticizer blend. Adipate esters can be used in combination with GP plasticizers to improve low-temperature performance. Plasticizer choices other than these are made only as necessary to provide required performance characteristics. 

Coatings for luggage exteriors must be durable. Typical compounds use 50-70 phr of DINP or DIDP, 10-20 phr calcium carbonate filler, colorants as required, 2-3 phr 5-7 p,m AZO, and 2-3 phr of a liquid activator-stabilizer. In almost all applications, DOP has been replaced with plasticizers of lower volatility. This is particularly true of automotive upholstery. DIDP blends with trimellitate plasticizers have become common use levels are typically about 80 phr, with 5-10 phr calcium carbonate, colorants as needed, 2-3 phr of 3 pm AZO, and 2-3 phr of activator-stabilizer. Lower residual odor is achieved with 3-5 phr 3 p,m OBSH instead. 

Phthalates, made by - esterification of phthalic acid anhydride with two moles of an alcohol (C7-C13), are the laigest-volume plasticizers for PVC. The alcohols are predominantly of petrochemical origin (e.g., ethylhexanol). However, straight-chain alcohols, such as octanol (- caprylic alcohol) or decanol (- capric alcohol), which can be derived from RR, are also used. Esters of these have better low-temperature performance and a lower viscosity than the branched-alcohol phthalates. Their lower volatility has led to their application in flexible PVC, especially in the automotive industry, to avoid fogging , which is the unwanted condensation of plasticizers on the windshield. These properties often compensate for their higher price. Do-decanol is employed in phthalates, where good high-temperature performanee is demanded. 

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