Dioctyl Sebacate DOS

Dioctyl sebacate is another synthetic ester plasticizer that is used to help achieve better low-temperature properties for compounds based on specialty elastomers. 

Di-(2-ethylhexyl) sebacate Sebacic acid, bis-(2-ethylhexyl) ester 

CH3(CH2)5CH0HCH3 + NaOOC(CH2)gCOONa-2-Octanol Sodium Sebacate 

The vast majority of sebacic acid production from castor oil occurs in China (about 90% of global production). 

ASTM D1992 can be used to classify adipate plasticizers. 

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Dioctyl sebacate (DOS) with relative permittivity e of 3.9 and 2-nitrophenyl octyl ether (NPOE) with e = 23.9 are the traditionally used sensor membrane plasticizers. The choice of a plasticizer always depends on a sensor application. Thus, NPOE appears to be more beneficial for divalent ions due to its higher polarity, but for some cases its lipophilicity is insufficient. Furthermore, measurements with NPOE-plasticized sensors in undiluted blood are complicated by precipitation of charged species (mainly proteins) on the sensor surface, which leads to significant potential drifts. Although calcium selectivity against sodium and potassium for NPOE-based membranes is better by two orders of magnitude compared to DOS membranes, the latter are recommended for blood measurements as their lower polarity prevents protein deposition [92],... 

Samples. CDC-treated nickel-plated steel sheets (nickel coating weight of 600 mg/m and chromium coating weight of 6 mg/m ) were oiled with about 5 mg/m of dioctyl sebacate (DOS) or acetyl tributyl citrate (ATBC) and were employed as original samples. 

Dioctyl Sebacate (DOS). See Di(2-ethylhexyl)-sebacate in this Vol and the Conf Propint Manual SPIA/M2 (1962) in which are described rocket propints Units 511 6ll using DOS as a plasticizer... 

Dioctotyl Sebacate. See under the title of Di(2-ethylhexyl) sebacate or Dioctolyl Sebacate (DOS) in Vol 5, D1237-L, and under the title of Dioctyl Sebacate (DOS) also in Vol 5, D1402-L to D1403-L. Also, the following Addnl Refs 1) C.J. Barr H.R. Weisbrod, Solid-Propellant Fuel Binder , USP 3138502... 

Other 2-ethylhexanol based plasticizers were introduced, including some which imparted outstanding low temperature flexibility—dioctyl adipate (DOA), dioctyl azelate (DOZ), dioctyl sebacate (DOS), and trioctyl phosphate (TOF). In addition, TOF showed high resistance to microorganisms which was important in military applications. Furthermore, TOF improved flame resistance. However, the mixed ester—octyl diphenyl phosphate—also introduced in the forties—was far superior and showed a better balance of low temperature performance and flame resistance than either TOF or the well-established plasticizer—tricresyl phosphate (TCP). Each of these found a market as a specialty plasticizer because of these specific performance attributes. None, however, was a serious threat to DOP on an overall price-performance basis. Rather, they were used to supplement the properties of DOP where its performance was inadequate. 

A hydrophobic cobyrinate (Figure 2, structure 2) was used to prepare solvent polymeric membranes (10). The typical membrane composition was 1% (w/w) ionophore, 66% (w/w) plasticizer and 33% (w/w) polymer. Electrodes prepared with this ionophore, dioctyl sebacate (DOS) and poly(vinyl chloride) (PVC) presented, at pH 6.6, the selectivity pattern shown in Figure 3. The response of the electrodes was near-Nernstian for salicylate, thiocyanate, and nitrite. Their selectivity behavior clearly deviates from that of the Hofmeister series, with nitrite being the anion that presents the larger deviation. 

SYNS BISOFLEXDOS DECANEDIOIC ACID, BIS(2-ETHYLHEXYL) ESTER DI(2-ETHYLHEXYL)SEBACATE DIOCTYL SEBACATE DOS 2-ETHYLHEXYL SEBACATE MONOPLEX DOS... 

The external plasticizing method is applied most frequently to polyvinyl chloride (PVC). The distance between the macromolecules of the plastics is increased by incorporation of plasticizer molecules [aromatic plasticizers, e.g., tricresyl phosphate (TCP) and aliphatic plasticizers, e.g., dioctyl phthalate (DOP) or dioctyl sebacate (DOS)]. This reduces the secondary bonding forces and increases chain segment mobility. Solvents (including water in polyamides) may also act by inward diffusion in a manner similar to plasticizers [11]. 

The obtained theoretical predictions have been verified in experiments on real elastomers. The elastomers tested in our experiments were amorphous polybutadiene urethanes (PBU) wifli polymer network of different density 0.3 kmol/m (PBU-1), 0.05 kmol/m (PBU-2), 0.2 kmol/m (PBU-3), 0.1 kmol/m (PBU-4). Oligooxypropylene triol - Laprol 373 was used as a crosslinking agent at the curing of prepolymer of oligobutadiene diol. The elastomer specimens were manufactured in the form of disks, 35 mm in diameter and 2 mm thick. The kinetics of specimen swelling was determined in low-molecular liquids toluene, dibutyl sebacate (DBS), dioctyl sebacate (DOS). 

Crosslinked PBU [(VeA o) 0-20 kmol/m ] and crosslinked elastomer of butadiene-nitrile rubber SCN-26 [(VeA o) 0.07 kmol/m ] were used in this study. The tests were carried out at 25+0.10 C in the following mixtures n-nonane-tributyl phosphate (TBP), n-hexane-dibutyl phthalate (DBP), n-hexane-dibutyl maleate (DBM), and dioctyl sebacate (DOS)-diethyl phthalate (DEP). A crosslinked elastomer SCN-26 was immersed to equilibrate in amyl acetate-dimethyl phthalate mixture. Liquid phase composition was in range of 5 to 10%. A sol-fraction of samples (plates of 0.9x10 m diameter and in 0.3x10 m thickness) was preliminary extracted with toluene. 

Samples of PBUU and SPU-10 were swollen to equilibrium in solvents of different polarity dioctyl sebacate (DOS), dioctyl adipate (DOA), dihexyl phthalate (DHP), transformer oil (TM), nitrile of oleic acid (NOA), dibutyl carbitol formal (DBCF), and tributyl phosphate (TBP). 

The network density of samples was estimated from the equilibrium compression modulus of samples swollen in suitable solvents. The samples were in the shape of a tablet 0.01 0.001 m in diameter and 0.002 0.0001 m in thickness. Samples with different initial concentrations of a plasticizer were prepared by the immersion of SKN-26 tablets in diethyl phthalate, DEP, for 5 days at 45 2°C and SKDU tablets in dioctyl sebacate, DOS, under the same conditions. Samples were periodically weighed, then thermostated in closed vessels for 3 days at 65 2°C after reaching a pre-determined weight. The PDU... 

Figure 8.9 shows that the presence of dioctyl sebacate, DOS, increases the effectiveness of crosslinker. Here, it is believed that increase in DOS, increases compatibility of the components and reaction proceeds with higher efBdency. 

The low temperature flexibility of NBR can be improved by the addition of dioctyl adipate (DOA) or dioctyl sebacate (DOS) type plasticizers. 

Polyfunctional Fatty Acid Esters. Dioctyl sebacate (DOS), dibutyl sebacate (DBS), diisobutyl adipate (DIBA), monoisopropyl citrate, stearyl citrate, triethyl citrate (TEC), butyl and octyl maleates, and fumarates are very important plasticizers for the preparation of stable PVC pastes and of low-temperature-resistant PVC products. DOS is used most often because of its high plasticization efficiency, its low volatility, and its resistance to water and soap solutions. It presents many advantages for PVC products. DBS, DIBA, and monoisopropyl, stearyl, and triethyl citrates are recommended for plastics components intended for packaging of food products. Butyl and octyl maleates and fumarates can be used for internal plasticization, that is, for copolymerization with vinyl chloride, vinyl acetate, and styrene. 

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