Dioctyl Adipate Research Articles

Migration of dioctyladipate plasticizer from food-grade PVC film into chicken meat products: effect of gamma-radiation.

Food-grade PVC film containing 28.3% dioctyladipate (DOA) plasticizer was used to wrap chicken meat samples, with and without skin, contained in a polystyrene tray. Samples were then irradiated with gamma-radiation [60Co] at doses equal to 4 kGy and 9 kGy corresponding to "cold pasteurization". Irraddiation was carried out at 8-10 degrees C and samples were subsequently stored at 4-5 degrees C. Contaminated chicken meat samples were analysed for DOA at intervals between 7 h and 240 h of contact, using an indirect GC method. Identical non-irradiated (control) samples were also analysed for their DOA content. Results showed no statistically significant differences in migrated amounts of DOA between irradiated and non-irradiated samples. Neither were differences observed between samples irradiated at 4 kGy and 9 kGy. This was supported by identical IR spectra recorded for irradiated and non-irradiated samples and leads to the conclusion that, at such intermediate radiation doses ( < or = kGy), the migration characteristics of PVC film are not affected. DOA migration was found to be time dependent, approaching equilibrium after approximately 170 h for the chicken flesh plus skin samples and 120 h for the chicken flesh samples. The amount of DOA migrated into chicken flesh plus skin samples was significantly greater (3.2-22.3 mg/dm2) than that for chicken flesh samples (0.9-8.9 mg/dm2). After 240 h of sample/film contact under refrigeration, loss of DOA was approximately 35.6% for chicken flesh plus skin samples and 14.3% for chicken flesh samples. Sample spoilage, as demonstrated by off-odour development, occurred after approximately 120 h of refrigerated storage. Diffusion coefficients for DOA were calculated and were found to be lower for chicken flesh (1 x 10(-13) than for flesh plus skin (4.4 x 10(-13)) samples.

Dual-Sorption Model of Water Uptake in Poly(vinyl chloride)-Based Ion-Selective Membranes: Experimental Water Concentration and Transport Parameters

An osmotic pressure-driven model for uptake of water in rubber is combined with dual-sorption-site theory to describe the transport of water in highly plasticized, poly(vinyl chloride) (PVC)-based ion-selective electrode membranes, both at equilibrium and during the initial stages of water uptake. During the first hour, mobile, miscible water is predicted to have a diffusion coefficient given by Dmo = D/(1 + Cis/so), where Dmo and D are the observed and true diffusion coefficients, respectively, Cis is the molar concentration of salt impurity and so is the maximum miscible water concentration. Addition of CoCl2 to PVC plasticized with dioctyl adipate (DOA) or nitrophenyl octyl ether (NPOE) showed that Dmo followed this expression during initial stages of water uptake. Values of D = (1.5 ± 0.1) × 10-6 cm2/s and so = 51 ± 5 mM, versus D = (4.3 ± 0.2) × 10-7 cm2/s and so = 82 ± 7 mM, were obtained for membranes with 66% DOA or NPOE as plasticizer, respectively. Added CoCl2 or KB(C6H5)4 reduced Dmo. The depen...

Mechanical properties of cellulose acetate propionate/aliphatic polyester blends

AbstractUseful blends of cellulose esters with other higher molecular weight polymers are generally unknown. Two aliphatic polyesters, poly(tetramethylene glutarate) (PTG) and poly(tetramethylene succinate) (PTS), have been thermally compounded with cellulose acetate propionate (CAP) in the range of 10–40 wt % polyester. These blends have been injection molded, and the mechanical properties of the molded bars were compared to bars molded from CAP plasticized with a low molecular weight diester, dioctyl adipate (DOA). The CAP/aliphatic polyester blends have significantly higher tensile strengths, flexural moduli, heat deflection temperatures, and greater hardness values than the corresponding CAP/DOA blends. © 1994 John Wiley &amp; Sons, Inc.

Evaluation of an ammonium ionophore for use in poly(vinyl chloride) membrane ion-selective electrodes: solvent mediator effects.

A macrotetrolide nonactin-based ammonium ionophore (AI) preparation containing 25% nonactin optimized for use in liquid membrane ion-selective electrodes was investigated for its possible use in poly(vinyl chloride) (PVC) matrix membrane-type electrodes. Nine different plasticizing solvent mediators were employed in the ammonium ion-selective membranes with PVC and the AI preparation. Near Nernstian responses were observed in aqueous solution with electrodes fabricated with dioctyl sebacate-, 2-nitrophenyl phenyl ether-, dibutyl sebacate-, trioctyl phosphate-, dioctyl adipate-, dioctyl phenyl phosphonate- and 2-nitrophenyl octyl ether-plasticized membranes. The responses of these electrodes were found to improve in the presence of a background concentration of non-interfering calcium ions.

Liquid rubber epoxy blends for Inhibition of Composite Propellants

AbstractLiquid rubbers, i.e. polysulphide (PS) and polybutadiene‐acrylic acid‐acrylonitrile (PBAN) have been blended with Dobeckot E‐4 (commercial novolak epoxy resin) in different proportions. These systems have been cured using polyamine/polyamide curing agents and were characterized using gel time, % elongation, tensile strength and bond strength with composite propellants, heat resistance, dioctyl adipate(DOA) absorption, oxygen index, thermal conductivity and brittleness temperature. The data generated for various characteristics indicate that the formulations E‐PS‐9 and E‐PBAN‐2 are promising inhibition systems for composite propellants.The inhibition of composite propellants has been done with rayon thread impregnated with the formulations E‐PS‐9 and E‐PBAN‐2 using filament winding technique. The successful static evaluation of inhibited composite propellants at ambient, elevated and sub‐zero temperatures proves the suitability of these systems for inhibition.

The migration of plasticizer in solid propellant grains

AbstractThe migration of the plasticizer, dioctyl adipate (DOA) in the accelerated ageing of composite propellant has been studied. The method is based on the extraction of DOA with carbon tetrachloride and its estimation by gas chromatography. The concentration of DOA in the propellant at different distances from the insulation was determined after a definite ageing period and compared with the initial DOA concentration. The effect of (a) the ageing period, and (b) the ageing temperature on the degree of migration was examined. The present studies confirm the existence of plasticizer migration in the propellant adjacent to the insulation, during ageing.

Migration of dioctylphthalate and dioctyladipate plasticizers from food-grade PVC films into ground-meat products

The migration of dioctylphthalate (DOP) and dioctyladipate (DOA) plasticizers from polyvinyl chloride (PVC) films into ground meat of varying fat contents was studied at 4°C and −20°C. The amount of migrating plasticizer was determined indirectly after the extraction, saponification and quantification of the alcoholic constituent of the ester plasticizer using gas chromatography. The amount that had migrated ranged from approximately 2 to 80 mg per kilogram of meat (0.12–4.8 mg/dm 2) after 8 days at 4°C and from 2 to 60 mg (0.13–4 mg/dm 2) after 2 1 2 months at −20°C. The amount of migrating DOA was (under similar experimental conditions) higher than the respective amount of DOP. The migration to samples of lower fat content was proportionally lower. Mathematical treatment of the migration of both DOA and DOP showed that the rate-determining step in the migration process is that of the diffusion of the plasticizer from the bulk of the PVC film to its surface.

Migration of dioctylphthalate and dioctyladipate plasticizers from polyvinylchloride films into olive oil

The migration of dioctylphthalate (DOP) and dioctyladipate (DOA) plasticizers from food grade polyvinylchloride (PVC) films into commercial olive oil has been studied. Olive oil was chosen as a fat simulant. Experiments were carried out at 6, 22 and 30°C with and without agitation as a function of time (0–100 h). Two different PVC films were used containing 31·5% DOA and 29·5% DOP, respectively. Results showed a significantly higher amount of plasticizer migration into oil with agitation than without (30% versus 22·2% for DOP after 100 h). The equilibrium amount of DOA migrated was found to be higher than the respective amount of DOP whereas diffusion coefficients determined were slightly higher for DOP than DOA. These findings were related to solubility, compatibility and molecular weight of plasticizer. Data were fitted to the Arrhenius equation and activation energies for diffusion of plasticizers in PVC were calculated.

Energetics and Compatibility of Plasticizers in Composite Solid Propellants

In this paper a comparative analysis on the energetics of ester type plasticizers such as dioctyl adipate (DOA), dioctyl phthalate (DOP),dibutyl sebacate (DBS), isodecyl pelargonate (IDP), trioctylphosphate (TOF), diethyl phthalate (DEP), tricresyl phosphate (TCP)and dibutyl phthalate (DBP) and hydrocarbon type plasticizers such as polybutene (PB), spindle oil, naphthenic oil, polymer extender oil(PEO) and poly isobutylene (PIB) and the impact of some of the plasticizers on the work ability, pot life and mechanical properties of propellants based on two selected polymeric binders namely polybutadiene-acrylic acid-acrylonitrile (PBAN) ter polymer andhydroxyl terminated polybutadiene (HTPB) have been reported. The compatibility of all the plasticizers on HTPB binder was also studied at different concentration levels and temperatures using Brookfield viscometer and reported. The mechanism of plasticization is also reviewed.

Optimisation of poly(vinyl chloride) matrix membrane ion-selective electrodes for ammonium ions

Poly(vinyl chloride)(PVC) matrix membrane electrodes for the determination of ammonium ions have been studied with respect to sensor and solvent mediator parameters. Nonactin, narasin, monensin and salinomycin were used as sensors and dioctyl adipate, diethyl adipate, 2-nitrophenyl phenyl ether, dioctyl phenylphosphonate, dioctyl sebacate, dibutyl phthalate and tripentyl phosphate as solvent mediators. The best ion-selective electrodes (ISEs) for ammonium ions were based on nonactin with dioctyl adipate as the plasticising solvent mediator, and the electrode based on salinomycin with dioctyl adipate as solvent mediator was its closest rival. The use of the copolymer VAGH (with 6% hydroxyl as vinyl alcohol) admixed with PVC produces matrix membranes of similar ammonium ISE properties to the PVC system and the free hydroxyl groups offer prospects for enzyme immobilisation when setting up enzyme electrodes for the determination of ammonium ions.

Modified poly(vinyl chloride) matrix membranes for ion-selective field effect transistor sensors

Various membrane compositions, in which a poly(vinyl chloride)(PVC)-poly(vinyl alcohol) copolymer (copolymer VAGH) and silicon tetrachloride were incorporated as additional components in the classical PVC matrix membrane composition for ion-selective electrodes, were studied for their adhesion characteristics to the gates of field effect transistor devices used for the construction of ion-selective field effect transistors (ISFETs). These studies were carried out on a potassium ion-sensing system based on valinomycin with dioctyl adipate as plasticising solvent mediator.The inclusion of 10–25%m/m copolymer VAGH and 1%m/m silicon tetrachloride in the membrane casting solution was found to increase the adhesion of the plastic membrane to the gate, reflected by an increase in ISFET functional lifetimes of 4–5 d over those which did not contain VAGH and by ca. 10 d over those which contained neither VAGH nor silicon tetrachloride. Leaching of membrane components is suggested as a factor limiting the ISFET lifetimes in adhesion studies.

Guanidinium ion-selective electrodes based on dibenzo-27-crown-9 and tetraphenylborate.

PVC membrane ion-selective electrodes based on dibenzo-27-crown-9 (DB27C9) and guanidinium tetraphenylborate (GuTPB) are described. Of six solvent mediators tested for DB27C9 based electrodes, dibutyl phthalate (DBP) gave the best fast response with near-Nernstian characteristics, followed by dioctyl adipate and dioctyl sebacate. 2-Nitrophenyl octyl ether, 2-nitrophenyl phenyl ether and dioctylphenyl phosphonate were unsatisfactory.The effect of GuTPB in electrode membranes with DBP as solvent mediator was studied. Addition to DB27C9 membranes produced less sensitive electrodes compared with those based on the crown ether alone, but the selectivity (separate solution method) towards guanidinium over some metal ions was improved. Electrodes based on GuTPB alone using DBP as a solvent mediator gave good responses and good selectivity towards guanidinium over metal ions but when dioctylphenyl phosphonate was used as the solvent mediator, the electrodes showed good all-round selectivity towards guanidinium ions. However, tetraphenylborate based electrodes were more sluggish in response.

Safety evaluation of a barrier cream.

A barrier cream containing propylene glycol, silica, xylene, dioctyl adipate and amyl acetate was applied topically for 3 months in 3 species of animal. Patch tests were carried out in human volunteers up to 72 h. The cream produced slight erythema in rats, guinea pigs and rabbits, but the irritation indices remained within safe limits. Histologically, mild focal thickening and moderate thickening of stratum corneum were observed in rats and guinea pigs, respectively, after 3 months of daily application. Patch testing in human volunteers indicated that the barrier cream is reasonably safe for human use.

Indirect food additive migration from polymeric food packaging materials.

Many foods contact polymeric packaging materials which contain residues of the polymerization process or additives employed to facilitate processing. The extent of migration of such materials from the packaging to foods is the focus of the present article. A major experimental program using eight polymer-migrant systems is described. Migration was measured to food-simulating liquids (FSL) and to foods. Accelerated tests were conducted with FSL under FDA guidelines conditions so as to develop correlations between such data and those found using foods under normal storage temperatures and shelf lives. In the majority of tests, the migration was found to be approximately proportional to the square root of time, to increase significantly with a rise in temperature, and to be proportional to the initial concentration of migrant in the polymer. Stirring in the FSL or food phase was generally not important except for the system involving dioctyl adipate migrating from polyvinyl chloride film. In some instances, after a period of time, migration rates became very low, and this effect was attributed to saturating the FSL or food phase with migrant. The foods comprised a variety of types, including liquid, semisolid, solid, and dry; both oily and aqueous foods were included. The physical steps involved in migration include the diffusion of the migrant from the interior of the film to the surface, where it can dissolve in the external FSL or food phase. The nature of the FSL or food is shown to be very important in that components can penetrate the polymer and dramatically increase migration rates. Consistent with the FDA guidelines in effect at the time of this study, testing was performed with five FSL (water, 3% acetic acid, 8% and 50% ethanol, and n-heptane) at 49 degrees C. Detailed comparisons were made between the migrations to foods and to FSL; following are the more relevant conclusions. (1) Three percent acetic acid showed no advantage over water as a food simulant even in those cases where the food could be considered acidic in nature. (2) Water, when used as an FSL at 49 degrees C for 5 days, overestimated migration in aqueous foods in about 75% of the cases. In some instances, however, the water phase became saturated with migrant. In other situations, this test protocol underpredicted migration--especially in those cases where there were components in the food that were able to penetrate into the polymer and enhance migration (such as orange juice).(ABSTRACT TRUNCATED AT 400 WORDS)

Assessment of the safety of dioctyl adipate in freshwater environments

AbstractA safety assessment of dioctyl adipate (DOA) in freshwater environments was conducted. DOA is relatively insoluble in water and is likely to partition to sediment and biota in the aquatic environment. Biodegradation was found to be rapid and extensive under conditions simulating sewage systems and the natural environment. Measured environmental concentrations of DOA averaged less than 0.5 μg/L in natural surface waters. DOA was not acutely toxic to algae and fish at or above its water solubility of 0.78 ± 0.16 mg/L. It was acutely and chronically toxic to Daphnia magna at 480 to 850 and 24 to 52 μg/L, respectively. A bioconcentration study with bluegill showed that DOA is not an accumulative or persistent chemical in this species. The mean 28‐d bioconcentration factor was 27. A comparison of the mean environmental water concentrations of DOA with laboratory chronic toxicity values for D. magna showed a safety margin of approximately three orders of magnitude. The conclusion drawn from this environmental safety assessment is that, under present use and disposal patterns, DOA presents a small hazard to the freshwater aquatic environment.

Mechanical properties of carboxyl terminated polybutadiene cured with epoxides

AbstractCarboxyl terminated polybutadiene (CTPB) has been cured with two trifunctional epoxides, ERL‐0510 and EPON 812, by means of ferric acetyl acetonate (FeAA) and chromium chelates of isopropyl salicylic acid (CrDIPS) as catalysts. In CTPB cured with ERL‐0510 there have been incorporated a carbon black, Sterling MT, and a plasticizer, dioctyl adipate (DOA). Tensile tests have been made at different temperatures and strain rates. The results of maximum stress, strain at break, and modulus have been treated according to the WLF‐equation to give temperature and rate reduced master curves. Addition of carbon black decreases strain at break and increases maximum stress and modulus. Addition of plasticizer increases strain at break and decreases maximum stress and modulus. CrDIPS gives the mixtures shorter curing time than FeAA. Polymers cured with the two epoxides have approximately the same strength properties.

Thermal analysis of the glass transition of plasticized poly(vinyl chloride)

AbstractEarlier studies by differential scanning calorimetry showed anomalous behavior of Tg with varying amounts of dioctyl phthalate, while by dynamic mechanical analysis 2 Tg's were found over a limited concentration range. In this study, two adjacent Tg's were found over the complete range of concentrations of dioctyl phthalate or dioctyl adipate, changing in relative contributions over the range. The results are shown to be consistent with the earlier work and to fit the Couchman model more closely than other models tested.

ASSESSMENT OF THE SAFETY OF DIOCTYL ADIPATE IN FRESHWATER ENVIRONMENTS

A safety assessment of dioctyl adipate (DOA) in freshwater environments was conducted. DOA is relatively insoluble in water and is likely to partition to sediment and biota in the aquatic environment. Biodegradation was found to be rapid and extensive under conditions simulating sewage systems and the natural environment. Measured environmental concentrations of DOA averaged less than 0.5 μg/L in natural surface waters. DOA was not acutely toxic to algae and fish at or above its water solubility of 0.78 ± 0.16 mg/L. It was acutely and chronically toxic to Daphnia magna at 480 to 850 and 24 to 52 μg/L, respectively. A bioconcentration study with bluegill showed that DOA is not an accumulative or persistent chemical in this species. The mean 28-d bioconcentration factor was 27. A comparison of the mean environmental water concentrations of DOA with laboratory chronic toxicity values for D. magna showed a safety margin of approximately three orders of magnitude. The conclusion drawn from this environmental safety assessment is that, under present use and disposal patterns, DOA presents a small hazard to the freshwater aquatic environment.

3 Final Report on the Safety Assessment of Dioctyl Adipate and Diisopropyl Adipate

Dioctyl Adipate, the diester of octyl alcohol and adipic acid, and Diisopropyl Adipate, the diester of isopropyl alcohol, are used in cosmetics as emollients and bases. These two ingredients have a low acute oral and percutaneous toxicity. Undiluted Dioctyl Adipate and Diisopropyl Adipate were, at most, only very mild, transient eye irritants. Primary dermal irritation tests indicated that Dioctyl Adipate was a very mild irritant and Diisopropyl Adipate was minimally irritating. Dioctyl Adipate was not a skin sensitizer in guinea pigs. An Ames test for the mutagenic potential of Dioctyl Adipate was negative. An assay of the carcinogenic potential of Dioctyl Adipate produced no untoward effects and was noncarcinogenic to rats. Mice studies indicated a dose- related body weight reduction and a higher incidence of hepatocellular adenoma and carcinoma than controls. In a lifetime study Dioctyl Adipate caused no skin tumors when 10 mg was applied weekly to the back skin of mice. The teratogenicity potential of Dioctyl Adipate is reviewed. Clinical assessment of Dioctyl Adipate in formulations showed, at most, minimal erythema and papules when applied under occlusion. No UV sensitization occurred. Undiluted Diisopropyl Adipate produced no irritation in 24 h patch tests, but was moderately irritating in a 21-day cumulative irritancy test. Formulations containing up to 20% Diisopropyl Adipate caused minimal to mild irritation, no sensitization and no photosensitization. On the basis of available data, it is concluded that Dioctyl Adipate and Diisopropyl Adipate are safe as presently used in cosmetics.

Evaluation of Emissions from Simulated Commercial Meat Wrapping Operations Using PVC Wrap

Meatwrapper's asthma is an elusive health problem with a suspected relationship to exposure to emissions from polyvinyl chloride (PVC) film cut with a hot wire. A study was conducted to determine how the type of wrap cutter (wire or rod) and its temperature affected the emissions from a simulated occupational wrapping process. The cutting temperatures covered the same range as was measured in Boston retail food stores. A commercial wrapping machine and samples of commercial PVC meat and produce wraps were used. Seventy five percent of the particulate from the hot wire was respirable, and the quantity of emissions was a strong function of the film tension and cutting technique. Particulate emissions did not increase steadily with increasing wire temperature, but plateaued or declined at high temperatures. Particulate emissions from the rod cutter were very low at low temperatures, but exceeded those of the wire at temperatures above 200°C. The particulate was 100% dioctyl adipate (DOA, the plasticizer in the wrap) with wire temperatures below 200°C, and was approximately 80% DOA for temperatures above this. Gaseous HC1 was not detected in emissions from a hot wire operated below 150°C, but HC1 emissions increased rapidly to a plateau for temperatures above 200°C. Approximately 20% of the HC1 produced at temperatures above 200°C was associated with the particulate, which appeared to act as a carrier and transport the HC1 through water filled impingers. Field tests are needed to determine if particulate produced in the workplace may also behave as a carrier for HC1.