Acetyl Tributyl Citrate Plasticizer Research Articles

Effect of Food-Simulating Liquids on the Leachability of Plasticizers from Dental Tissue Conditioners.

Tissue conditioners are composed of poly(ethyl methacrylate) (PEMA) powder and plasticizer/ethanol mix liquid. Butyl phthalyl butyl glycolate (BPBG) plasticizer is commonly used in tissue conditioners, but the main concern with phthalate plasticizer is its leachability and biocompatibility, especially the estrogenic activity and cytotoxicity of phthalate. Therefore, acetyl tributyl citrate (ATBC) plasticizer has been introduced and formulated as plasticizer in tissue conditioner; however its leachability characteristics are still unknown. Furthermore, the effect of foodsimulating liquids toward leachability of BPBG and ATBC plasticizers has not been documented. The objective of this study was to compare the effect of food-simulating liquids on the leachability of plasticizers and hardness of two experimental tissue conditioners containing BPBG and ATBC plasticizers. Ten experimental materials were prepared using PEMA polymer powder with 95% plasticizer (BPBG and ATBC) and 5% ethanol by volume, using powder to liquid ratio of 1.67:1, and the thickness was controlled at 3 mm. Shore A hardness value was measured after immersion in distilled water, artificial saliva, 25% ethanol/water mix, 3% citric acid, and coconut oil at 37°C. Measurements were taken at 2 hours and 1, 2, 3, 4, 7, 10, 14, 21, 28, 42, 56, and 84 days. Six readings were taken for each sample and hardness change was calculated and statistically analyzed using Wilcoxon signed-rank test. Increase in hardness value was noted for both plasticizers over time with the highest increase was when immersed in coconut oil. Shore A hardness value was significantly higher in ATBC after 84 days of immersion in all food-simulating liquids. The increase in hardness is due to plasticizer/ethanol leaching; however, as ethanol content was the same (5%), the hardness change is attributed to the leaching of plasticizers. Leaching of both plasticizers was highest in coconut oil indicating that tissue conditioners may have a shorter intraoral lifetime in patients eating high-fat diet.

Developmental toxicity and thyroid hormone-disrupting effects of acetyl tributyl citrate in zebrafish and Japanese medaka

Chemical pollution from plasticizers in water environments is a serious environmental problem worldwide. Phthalate plasticizers have potential endocrine-disrupting effects in vertebrates. In this study, the effects of a non-phthalate acetyl tributyl citrate (ATBC) plasticizer on endocrine hormone activity (according to thyroid-related gene expression) and the developmental toxicity of ATBC were determined in zebrafish (Danio rerio) and Japanese medaka (Oryzias latipes) embryos. ATBC exposure increased the mortality of zebrafish and Japanese medaka at concentrations of 443.05 and 1,937.41 μg/L, respectively. Body curvature, edema, and growth inhibition were also observed after ATBC exposure in both species. Importantly, both species exhibited suppressed thyroid-related gene mRNA expression after ATBC exposure. ATBC exposure significantly suppressed the expression of thyroid-stimulating hormone beta subunit (tshβ), iodothyronine deiodinase 1 (dio1), dio2, and thyroid hormone receptor alpha (trα) in zebrafish. In Japanese medaka, ATBC exposure suppressed the mRNA expression of dio2, trα, and trβ but not tshβ and dio1. In summary, ATBC exposure inhibited thyroid-related gene expression and led to improper swim bladder inflation in the test species. This is the first report of a non-phthalate ATBC plasticizer inducing abnormal embryo development and disrupting thyroid hormone activity in fish.

Analytical Modeling of Stress Relaxation and Evaluation of the Activation Volume Variation: Effect of Temperature and Plasticizer Content for Poly(3-hydroxybutyrate-3-hydroxyvalerate).

In this study, stress-relaxation tests that have been carried out at different temperatures (quite below the heat deflection temperature) on a poly(3-hydroxybutyrate-3hydroxyvalerate) (PHB-HV) matrix containing different amounts of the acetyl tributyl citrate plasticizer (added at 5 and 10 wt %) are investigated. The analytical modeling of the stress relaxation behavior by the coupling of Eyring’s approach and the Guiu and Pratt model is successful. The activation volume results achieved are very interesting; in fact, not only the dependence of the activation volume from temperature is confirmed (and it resulted in dependence from the α′ relaxation temperature) but also, for the first time, the dependence of the activation volume from the plasticizer content is shown. In particular, the presence of a linear relationship between the activation volume and the plasticizer volume content is observed.

The Influence of Additives and Environment on Biodegradation of PHBV Biocomposites

The biodegradation of polyhydroxybutyrate-co-hydroxyvalerate (PHBV) ternary biocomposites containing nature-based plasticizer acetyl tributyl citrate (ATBC), heterogeneous nucleation agents—calcium carbonate (CaCO3) and spray-dried lignin-coated cellulose nanocrystals (L-CNC)—in vermicomposting, freshwater biotope, and thermophilic composting have been studied. The degree of disintegration, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and the evaluation of surface images taken by scanning electron microscopy (SEM) were conducted for the determination influence of different environments and additives on the biodegradation of PHBV. Furthermore, the method adapted from ISO 14855-1 standard was used for thermophilic composting. It is a method based on the measurement of the amount of carbon dioxide evolved during microbial degradation. The highest biodegradation rate was observed in the thermophilic condition of composting. The biodegradation level of all PHBV-based samples was, after 90 days, higher than 90%. Different mechanisms of degradation and consequently different degradation rate were evaluated in vermicomposting and freshwater biotope. The surface enzymatic degradation, observed during the vermicomposting process, showed slightly higher biodegradation potential than the hydrolytic attack of freshwater biotope. The application of ATBC plasticizers in the PHBV matrix caused an increase in biodegradation rate in all environments. However, the highest biodegradation rate was achieved for ternary PHBV biocomposites containing 10 wt. % of ATBC and 10 wt. % of CaCO3. A considerable increase in the degree of disintegration was evaluated, even in freshwater biotope. Furthermore, the slight inhibition effect of L-CNC on the biodegradation process of ternary PHBV/ATBC/L-CNC could be stated.

Crystallinity study of nano-biocomposites based on plasticized poly(hydroxybutyrate-co-hydroxyvalerate) with organo-modified montmorillonite

The influence of nanofiller, plasticizer and hydroxyvalerate (HV) contents on the properties of poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV)/clay nano-biocomposites is studied.Analyses by wide-angle X-ray diffraction and differential scanning calorimetry showed that both the organo-modified montmorillonite clay and acetyl tributyl citrate plasticizer facilitate the crystallization process of PHBV. Despite its nucleating effect, the nanoclay hampers the spherulite growth and leads to a reduction in the copolymer crystallinity, while the addition of plasticizer induces the formation of thicker spherulites.For all studied systems, it was shown that the variation of mechanical properties of these nano-biocomposites is strongly influenced by their changes in crystallinity.

Processability and mechanical properties of commercial PVC plastisols containing low‐environmental‐impact plasticizers

AbstractPreliminary results are presented concerning the use of less‐toxic plasticizers such as dioctyl adipate (DOA) and acetyl tributyl citrate (ATBC) in plastisol formulations for rotational molding technology. The DOA and ATBC plasticizers have been studied by comparing the effects of their content, molecular architecture, and polarity on the rheological behavior of liquid plastic systems and on the mechanical properties of the ultimate products prepared with PVCs having different particle sizes and molecular‐weight distributions. Rheological tests have confirmed the differences in solvent power of the diethylhexyl phthalate (DOP), DOA, and ATBC plasticizers. The glass transition temperatures measured on rotomolded samples have shown that the use of ATBC leads to a more nearly rigid system as a consequence of the branched structure and polarity of this plasticizer when compared with DOA. Mechanical tests carried out on final products after natural and forced environmental aging revealed a slight decrease in their performance. J. VINYL ADDIT. TECHNOL., 2009. © 2009 Society of Plastics Engineers

Migration of di(2-ethylhexyl) adipate and acetyltributyl citrate plasticizers from food-grade PVC film into sweetened sesame paste (halawa tehineh): Kinetic and penetration study

Food-grade polyvinyl chloride (PVC) cling-film containing 5.3% (w/w) di(2-ethylhexyl) adipate (DEHA) and 3.0% (w/w) acetyltributyl citrate (ATBC) plasticizers was used to wrap halawa tehineh (halva) samples. Samples were split into two groups and stored at 25 ± 1 °C. One group was analyzed for DEHA and ATBC content at intervals between 0.5 and 240 h of contact (kinetic study) and a second group was cut into slices (1.5 mm thick) after 240 h of halva/PVC contact and was analyzed for DEHA and ATBC content (penetration study). Determination of both plasticizers was performed using a direct gas chromatographic (GC) method after extraction of DEHA from halva samples. DEHA readily migrated into halva samples: the equilibrium amount of DEHA in halva (3.31 mg/dm 2 film or 81.4 mg/kg halva) corresponding to a loss of 54.7% (w/w) DEHA from PVC film. This value is slightly higher than the limit of 3 mg/dm 2 of film surface set by the European Union for DEHA. The equilibrium amount of ATBC in halva was 1.46 mg/dm 2 (36.1 mg/kg) corresponding to a loss of 42.7% ATBC from PVC film. With regard to the penetration of both placticizers into halva samples, migration of DEHA was detectable up to the 7th slice beneath the surface of halva (total depth 10.5 mm) while the migration of ATBC was detectable up to the 5th slice (total depth 7.5 mm).

Migration of di-(2-ethylhexyl)adipate and acetyltributyl citrate plasticizers from food-grade PVC film into isooctane: Effect of gamma radiation

The effect of gamma radiation on the migration of both di-(2-ethylhexyl)adipate (DEHA) and acetyltributyl citrate (ATBC) plasticizers from PVC film into the food simulant isooctane was studied as a function of time (0–48h) at 20°C. Food-grade PVC cling-film used contained 5.3% (w/w) DEHA, 3.0% (w/w) ATBC and polyadipate polymeric plasticizer. Irradiation of the films was carried out at doses of 5, 10 and 25kGy using a [60Co] gamma-radiation source. Determination of both plasticizers was performed using a direct gas chromatographic method. No radiation-induced transformation of the two plasticizers was observed after absorbed doses of 5–25kGy. DEHA migrated rapidly into isooctane in contrast with ATBC. ATBC migrating amounts at equilibrium were approximately three times lower than the corresponding amounts of DEHA. Irradiation at doses 10 and 25kGy had a small but statistically significant (P<0.05) effect on the migration of both DEHA and ATBC into isooctane. Migration amount increased with increasing irradiation dose and contact time. The irradiation-induced increase of ATBC migration was significantly higher than the corresponding increase of DEHA migration. Results are discussed in relation to EU proposed upper limit for DEHA specific migration (18mg/L). Diffusion coefficients for both plasticizers calculated, showed differences between irradiated and control samples.

Effect of microwave versus conventional heating on the migration of dioctyl adipate and acetyltributyl citrate plasticizers from food grade PVC and P(VDC/VC) films into fatty foodstuffs

The effect of microwave heating versus conventional heating on the migration of dioctyl adipate (DOA) and acetyltributyl citrate (ATBC) plasticizers from plasticized poly(vinyl chloride) (PVC) and poly(vinylidene chloride/vinyl chloride) (P[VDC/VC]) films into pizza and frankfurter-type sausages has been studied. Microwave heating was carried out with and without a susceptor. The plasticizer migrating into the food was determined using an indirect gas chromatographic method after saponification of the ester-type plasticizer (DOA or ATBC) and subsequent collection of the alcoholic component of the ester, namely 2-ethyl-1-hexanol and 1-butanol, respectively. The extent of migration of both plasticizers into pizza and sausage followed the sequence: heating in conventional oven > microwave heating with a susceptor > microwave heating without a susceptor. The amounts of DOA that migrated into pizza and sausage were 105.12 mg/kg and 85.01 mg/kg during conventional heating, 75.52 mg/kg and 47.69 mg/kg during microwave heating with a susceptor and 51.42 mg/kg and 37.98 mg/kg during microwave heating without a susceptor, respectively. The amounts of ATBC that migrated into pizza and sausage were 31.18 mg/kg and 25.37 mg/kg during conventional heating, 7.73 mg/kg and 7.02 mg/kg during microwave heating with a susceptor and 6.25 mg/kg and 5.17 mg/kg during microwave heating without a susceptor.

Effect of microwave heating on the migration of dioctyl adipate and acetyltributyl citrate plasticizers from food grade PVC and PVDC/PVC films into ground meat

Migration of dioctyl adipate (DOA) and acetyltributyl citrate (ATBC) plasticizers from plasticized poly(vinyl chloride) and poly(vinylidene chloride/vinyl chloride) films into ground meat of varying fat content (3%, 12%, 30%, 55%) during microwave heating has been studied. The plasticizer migrating into ground meat was determined using an indirect gas chromatographic method after saponification of the ester-type plasticizer (DOA or ATBC) and subsequent collection of the alcohol component of the ester, namely 2-ethyl-1-hexanol and 1-butanol, respectively. Identical unwrapped microwave heated (control) samples were also analysed for DOA and ATBC content. Migration was dependent on heating time, fat content of the meat and the initial concentration of the plasticizer in the film. Migration of DOA and ATBC into ground meat did not reach equilibrium after heating for 4 min at full power even for meat samples of high fat content (55%). Migration values of DOA and ATBC into ground meat of 55% fat content after 4 min of heating in a microwave oven were 172.39 mg/kg (14.62 mg/dm2) and 17.24 mg/kg (0.62 mg/dm2), respectively. Migration into control samples was below the detection limit of the method employed (<2 mg/kg for DOA and <2.5 mg/kg for ATBC).

Effect of High-Dose Electron Beam Irradiation on the Migration of DOA and ATBC Plasticizers from Food-Grade PVC and PVDC/PVC Films, Respectively, into Olive Oil

The effect of high-dose irradiation on the migration of dioctyl adipate (DOA) and acetyl tributyl citrate (ATBC) plasticizers from food-grade poly(vinyl chloride) (PVC) and poly(vinylidene chloride/vinyl chloride) (PVDC/PVC) copolymer (Saran) films, respectively, into olive oil was studied. The results showed a significantly higher amount of DOA migrated into olive oil from irradiated versus nonirradiated samples. This difference was more noticeable in oil samples collected during initial periods of contad. The amount of DOA migrating into olive oil was lower for samples irradiated at a dose of 20 kGy in comparison with samples irradiated at adose of 50 kGy. At a sampling time of 1 h the amount of DOA that migrated into olive oil was 93.9 mg/liter, 141.5 mg/liter, and 183.4 mg/liter for nonirradiated samples, 20-kGy irradiated samples, and 50-kGy irradiated samples, respectively. After 288 hr (12 days) of oil-film contad the respective amounts were 390.8 mg/liter, 409.2 mg/liter, and 430.1 mg/liter. There were no statistically significad differences in migrating amount of ATBC between nonirradiated samples and samples irradiated at a dose of 20 kGy, while in samples irradiated at a dose of 50 kGy the migration of ATBC was increased. After 1 h of oil-film contad no detectable amounts of ATBC had migrated. After 288 h of contad the amounts of ATBC that migrated into olive oil were 3.59 mg/liter, 3.56 mg/liter, and 4.12 mg/liter for nonirradiated samples, 20-kGy irradiated samples, and 50-kGy irradiated samples, respectively. It is suggested that plasticized PVC should not be used in direct contact with high-fat foodstuffs with or without irradiation treatment.

Effect of microwave heating on the migration of dioctyladipate and acetyltributylcitrate plasticizers from food-grade PVC and PVDC/PVC films into olive oil and water.

Migration of dioctyladipate (DOA) and acetyltributylcitrate (ATBC) plasticizers from plasticized polyvinylchloride (PVC) and polyvinylidene chloride (PVDC)/PVC (Saran) films into both olive oil and distilled water during microwave heating has been studied. The plasticizer migrating into olive oil and water was determined using an indirect GC method after saponification of the ester-type plasticizer (DOA or ATBC) and subsequent collection of the alcohol component of the ester, namely: 2-ethyl-1-hexanol and 1-butanol, respectively. Migration was dependent on heating time, microwave power setting, the nature of the food simulant and the initial concentration of the plasticizer in the film. Migration of DOA into olive oil reached equilibrium after heating for 10 min at full power (604.6 mg DOA/l). Migration into distilled water was 74.1 mg/l after 8 min of microwave cooking at full power. The amount of ATBC migrating into olive oil reached equilibrium after heating for 10 min at full power (73.9 mg ATBC/l). Migration into distilled water was 4.1 mg/l after heating at full power for 8 min. Control samples containing olive oil gave DOA migration values which were significantly higher than the upper limit for global migration (60 mg/l) set by the European Community. It is proposed that PVC should not be used in direct contact with food in the microwave oven, while Saran may be used with caution in microwave heating and reheating applications, avoiding its direct contact with high fat foodstuffs.