Ozonation of a mixture of dialkylphthalates in aqueous solution

Ozonation of dimethyl phthalate, diethyl phthalate and dipropyl phthalate was carried out to evaluate the potential of ozonation for phthalate removal from water. Phthalates with longer alkyl chains, which are often more resistant to biodegradation were found to be more degradable than those with shorter alkyl chains. The degradation of phthalates by ozonation follows the pseudo‐first‐order kinetic model. The rate of phthalates degradation increased exponentially with increasing temperature in the range studied (20 to 50 °C) and in proportion with applied ozone dosages. The rate of phthalates degradation was found to increase with increasing pH of the solution from 2.6 to 11.0, and decreased exponentially with increasing initial concentrations of the phthalates. Degradation of phthalates via ozonation was found to develop dominantly through direct reaction with hydroxyl radicals. Copyright © 2010 Society of Chemical Industry     

邻苯二甲酸酯标准塑料的制备及其物理化学性质

以聚氯乙烯(PVC)为基体,制备了6种邻苯二甲酸酯标准塑料。对该塑料进行了拉伸性能检测,测定了邻苯二甲酸酯的准确含量,采用方差分析法进行了均匀性、稳定性评价,并计算了邻苯二甲酸酯含量的不确定度。结果表明:标准塑料的拉伸性能、均匀性和稳定性良好,能够满足准确测定PVC中邻苯二甲酸酯增塑剂的要求。     

Revisiting analysis of phthalate plasticizers concentration in poly(vinyl chloride)

The method of the efficient analysis of di(2‐diethylhexyl) phthalate, tri(2‐ethylhexyl) trimellitate, di(2‐ethylhexyl) terephthalate, and other phthalate plasticizers concentrations in plasticized poly(vinyl chloride) (PVC) was developed. The method is based on quantitative dissolution of the PVC sample in methyl ethyl ketone with the consequent precipitation of PVC with hexane and concentration of phthalate in an organic layer. A capillary column‐based gas chromatographic technique for phthalates separation and quantification was developed and used in conjunction with the PVC and phthalates dissolution technique. The developed method of phthalate plasticizers analysis proved to be relatively fast, reproducible, and straightforward. J. VINYL ADDIT. TECHNOL., 21:197–204, 2015. © 2014 Society of Plastics Engineers     

Supercritical CO2 extraction of phthalate plasticizers from PVC

Three common phthalates, namely, dioctyl phthalate, diisodecyl phthalate, and trioctyl trimellitate, were used as plasticizers for poly(vinyl chloride) (PVC) processing, and the extraction of these plasticizers were investigated using supercritical CO₂ fluids. Factors affecting the extractions of these phthalates were focused. The molecular weight of phthalates was found to dominate the level of extraction of low temperatures, whereas the content of carbonyl groups in the phthalate was a determining factor for the level of extraction of high temperatures. Negligible extraction was observed below the critical pressure of CO₂. For 32°C, the level of the extraction is insignificant below density of ca 0.7 g/cm³, above which the level of the extraction increases roughly linearly with increasing density. For temperatures above 32°C, the density of CO₂ for apparent extractions decreased with increasing temperatures. The threshold density of CO₂ for extractions was found to be independent of the amount of a given phthalate in PVC. Two extraction rates during the extraction could be determined, with a higher rate in the first hour followed by a lower rate later in the extraction for all three phthalates. The effects of the extractions of phthalates on the flexibility of PVC were also investigated as well as the effects of the extrusion conditions, which could lead to various degrees of plasticization of PVC, on the level of extractions. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 4032–4037, 2003     

气相色谱法测定烟用胶中邻苯二甲酸酯类物质

采用丙酮萃取烟用胶中邻苯二甲酸酯类物质,所得萃取液用气相色谱测定了3种邻苯二甲酸酯类物质。DB-5毛细管色谱柱(30 m×0.5 3mm×1.50μm)用于气相色谱分离,氢火焰离子化检测,采用柱温300℃和检测器温度275℃,载气为氦气,流速20 mL/min,测得邻苯二甲酸二丁酯,邻苯二甲酸二丁基苄酯,邻苯二甲酸二辛酯的最小检出限为0.5μg/g,0.5μg/g,1μg/g。回收率在94.3%~105.5%之间,RSD在0.7%~3.2%之间。     

邻苯二甲酸酯增塑剂对健康和环境影响的评估及其对消费量的影响

综述了邻苯二甲酸酯增塑剂在全球消费的情况及其受环保压力的影响。最近许多论文指出:常用的邻苯二甲酸酯都是易于生物降解的,并无生物累积作用,对环境各个方面都没有影响;公认由邻苯二甲酸酯导致啮齿动物的致癌性是由于物种特殊性所决定的,和人类没有关系;邻苯二甲酸酯在低剂量下并不产生拟激素效应,因而不是内分泌调节剂。上述信息继续支持邻苯二甲酸酯用于增塑聚氯乙烯。并总结了立法和环保压力与工业界响应之间争论的焦点。     

溶解-沉淀-GC/MS法测定聚氯乙烯塑料中的邻苯二甲酸酯类增塑剂

建立了用溶解-沉淀-GC/MS法同时测定聚氯乙烯(PVC)塑料中15种邻苯二甲酸酯类增塑剂的分析方法。选择四氢呋喃作溶剂将PVC树脂溶解,然后用甲醇作为沉淀剂将高聚物进行沉淀,使增塑剂与高聚物进行分离而增塑剂继续留在溶液中,取清液进行气相色谱-质谱分析。本实验选择了适当的溶剂与沉淀剂,考察了聚合物分子沉淀对目标化合物的吸附作用,在优化的色谱-质谱条件下实现了15种邻苯二甲酸酯的成功分离与检测,方法平均回收率为82.7%～112.4%,测定结果的相对标准偏差为2.15%～5.77%,测定下限(S/N=10)为25～50mg/kg。该方法操作简便,精密度高,准确性好,实用性强,与国家标准GB/T22048—2008相比,检测结果基本一致,而效率大大提高。应用此方法对两种PVC塑料实际样品中的邻苯二甲酸酯进行测定,获得满意结果。     

邻苯二甲酸酯性能与原料醇组成的关系

以邻苯二甲酸酐和脂肪醇为原料,硫酸氢钠为催化剂合成了一系列邻苯二甲酸酯。考察了脂肪醇的链长度、类型及支链醇含量等因素对合成酯性能的影响,结果表明,随着脂肪醇链长的增加,合成酯的黏度和黏度指数逐渐增大,倾点升高;碳原子数目相同的支链醇酯较直链醇酯具有更高的黏度、倾点和闪点以及更低的黏度指数;在直链醇中引入支链醇,所得合成酯的黏度增大,黏度指数减小,倾点和闪点升高;且随着支链醇含量的增加,合成酯的黏度总体呈增大趋势,黏度指数逐渐减小,倾点和闪点呈锯齿型变化。     

Studies on lipid biosynthesis and cholesterol content of liver and serum lipoproteins in rats fed various phthalate esters

The effect of various phthalate ester plasticizers on lipid metabolism in rats was studied in vivo and in vitro. Di-2-ethylhexyl phthalate (DEHP) and di-n-butyl phthalate (DBP) inhibited (30–70%) hepatic sterologenesis from¹⁴C-acetate and¹⁴C-mevalonate in liver minces from rats fed the phthalates at a level of 2.5 mmoles/100 g of chow diet for 21 days; inhibition of¹⁴C-acetate incorporation into phospholipids, triglycerides, and steryl esters was reduced (35–70%) by DEHP and DBP feeding. In addition, serum cholesterol was lowered ca. 14 mg/dl with dietary DEHP or DBP but not with dimethyl phthalate (DMP). Hepatic total cholesterol levels were reduced significantly (31%, P<0.001) by DMP but not by DBP or DEHP. In other studies with DEHP fed at the 0.5% level in chow diets (1.3 mmoles/100 g), the incorporation (esterification) of³H-oleate into di- and triglycerides was reduced ca. 40%. Furthermore, the addition of DEHP (2%, 5 mmoles/100 g) to a semisynthetic diet containing 10% fat (hydrogenated coconut oil) resulted in changes in serum lipoprotein composition. The percentage of serum cholesterol in LDL rose from 22% to 34% while that in HDL fell from 78% to 66%; these changes occurred without net changes in serum cholesterol levels. Possible mechanisms for the inhibitory effect of phthalates on hepatic lipid biosynthesis are discussed. These studies are in partial fulfillment of the requirements for a Doctorate degree in Medical Sciences, McMaster University, Hamilton, Ontario, Canada.     

Removal of Refractory Organics by Aeration. VI. Solvent Sublation of Alkyl Phthalates

Abstract

The solvent sublation of diethyl, di-n-butyl, and bis(2-ethylhexyl) phthalates in a batch-type laboratory scale apparatus is reported. Removals of all three are accelerated by added NaCl and markedly decreased by ethanol. The rate of removal of diethyl phthalate is much slower than the rates of removal of di-n-butyl and bis(2-ethylhexyl) phthalates.     

Synthesis and Evaluation of Soy Fatty Acid Ester Estolides as Bioplasticizers in Poly(Vinyl Chloride)

Plasticizers are nonvolatile organic liquids that impart flexibility to polymers. Due to environmental, health, and safety reasons, the industry is looking for bioplasticizers to replace petroleum-derived phthalates. To fulfill this need, soy fatty acid ester estolides were synthesized, characterized, and evaluated as phthalate replacements. Soybean oil was transesterified with methanol or glycerol to form lower molecular weight fatty acid esters that were epoxidized and ring opened with acetic acid and acetylated to give the final products. Ring opening and acetylation of the epoxidized oleic acid esters gave acyclic acetate fatty acid ester estolides, whereas the polyunsaturated fatty acid esters, linoleate, and linolenate gave cyclic tetrahydrofuran derivatives and cross-linked higher molecular weight materials. The cyclization mechanism to form the tetrahydrofuran derivatives was postulated. Soy fatty acid ester estolides were compounded with formulated poly(vinyl chloride), (PVC) and tested for their functional properties. The physical and functional properties of the new bioplasticizers were compared with commercial plasticizers. The elasticity of PVC compounded with experimental plasticizers and commercial phthalates was comparable. PVC compounded with fatty acid methyl ester estolide showed lower glass transition temperature and similar tensile properties compared to PVC compounded with the commercial phthalate. PVC compounded with the glyceryl fatty acid ester estolide showed a higher glass transition temperature, higher tensile properties compared to PVC compounded with the commercial phthalate.     

Diffusivities of Dialkyl Phthalates in Plasticized Poly(vinyl butyral): Impact on Binder Thermolysis

Hot-stage/Fourier transform infrared microspectroscopy (FTIR-M) was used to determine the diffusivities of a series of dialkyl phthalates in poly(vinyl butyral) (PVB) spin-coated films. The diffusivities ranged from 10⁻¹² to 10⁻¹⁰ cm²/s for the isotherms investigated (60° to 150°C). In their respective temperature regimes, dimethyl phthalate and diethyl phthalate exhibited nonlinear diffusion behavior, while dibutyl phthalate (DBP) and dioctyl phthalate (DOP) exhibited Fickian behavior in PVB. The activation energies for DBP and DOP diffusion in the PVB-based films were calculated to be 76.3 and 114.7 kJ/mol, respectively. The diffusitivity of DBP was used to compare the relative importance of diffusion and capillary migration in the thermolysis of PVB-DBP binders from ceramic greenware. Comparison of the calculated DBP loss due to diffusion alone could not account for the observed removal rates. A characteristic diffusion length is calculated from the experimental observations.     

Performance of Di-n-Hexyl phthalate in flexible vinyl formulations

Low-molecular-weight esters have been available to the PVC compounder for many years. They have found a significant niche in the performance vs. permanence compromise as a compound ingredient that provides manufacturing efficiency or some special property with adequate permanence for many vinyl applications. In many respects, low-molecular-weight esters are the processing aids of the plasticizer family. This group of plasticizers may be said to include C₄ to C₇ dialkyl phthalates, the benzyl phthalates and the benzoic acid esters. This paper will introduce and compare di-n-hexyl phthalate (DNHP) to other phthalates against which it will directly compete.     

The migration of plasticizers from poly(vinyl chloride) into edible oils

The migration of phthalate plasticizers from poly (vinyl chloride) into edible oils has been analyzed. The principal method used involved ¹⁴C-labeled dibutyl and dioctyl phthalates with detection by liquid scintillation spectrophotometry. In most cases, the migration of the main plasticizer was accompanied by the migration of the secondary plasticizer, when present, and by diffusion of the oil into the polymer. Comparison of the scintillation results with those obtained by weight loss measurements can give quantitative information on the amount of the liquid medium that diffuses during the migration process. The effect of the following factors on the migration process was examined; (a) the nature and acidity of the edible oil, (b) the composition and amount of phthalate plasticizer, (c) the amount of epoxy plasticizer, and (d) the temperature and time of contact.     

Epigenetic effects of environmental chemicals bisphenol a and phthalates

The epigenetic effects on DNA methylation, histone modification, and expression of non-coding RNAs (including microRNAs) of environmental chemicals such as bisphenol A (BPA) and phthalates have expanded our understanding of the etiology of human complex diseases such as cancers and diabetes. Multiple lines of evidence from in vitro and in vivo models have established that epigenetic modifications caused by in utero exposure to environmental toxicants can induce alterations in gene expression that may persist throughout life. Epigenetics is an important mechanism in the ability of environmental chemicals to influence health and disease, and BPA and phthalates are epigenetically toxic. The epigenetic effect of BPA was clearly demonstrated in viable yellow mice by decreasing CpG methylation upstream of the Agouti gene, and the hypomethylating effect of BPA was prevented by maternal dietary supplementation with a methyl donor like folic acid or the phytoestrogen genistein. Histone H3 was found to be trimethylated at lysine 27 by BPA effect on EZH2 in a human breast cancer cell line and mice. BPA exposure of human placental cell lines has been shown to alter microRNA expression levels, and specifically, miR-146a was strongly induced by BPA treatment. In human breast cancer MCF7 cells, treatment with the phthalate BBP led to demethylation of estrogen receptor (ESR1) promoter-associated CpG islands, indicating that altered ESR1 mRNA expression by BBP is due to aberrant DNA methylation. Maternal exposure to phthalate DEHP was also shown to increase DNA methylation and expression levels of DNA methyltransferases in mouse testis. Further, some epigenetic effects of BPA and phthalates in female rats were found to be transgenerational. Finally, the available new technologies for global analysis of epigenetic alterations will provide insight into the extent and patterns of alterations between human normal and diseased tissues. In vitro models such as human embryonic stem cells may be extremely useful in bettering the understanding of epigenetic effects on human development, health and disease, because the formation of embryoid bodies in vitro is very similar to the early stage of embryogenesis.     

Optimizing performance of benzoate and phthalate blends for vinyl applications

To achieve required performance, blends of plasticizers are commonly used in flexible vinyl applications. Typically, when fast fusion is required, high solvating phthalates have been utilized in plasticizer blends. Benzoate esters are high solvators and can also be used in these blends. However, even though benzoate plasticizers offer additional performance benefits that can complement general‐purpose phthalate performance, most of the literature does not include the use of benzoate plasticizers in blends with phthalates. The purpose of this article is to demonstrate the performance benefits of blending benzoate and phthalate plasticizers. The approach selected to accomplish this task was to develop performance data by utilizing a mixture design approach with DOE (design of experiments) software. A resilient flooring plastisol formulation was selected as the model. The following properties were obtained: degassing, low and high shear viscosity, viscosity stability of the plastisol, gel and fusion characteristics, tensile strength vs. temperature, vinyl heat stability, stain resistance, volatility, and UV stability. The data indicate how to utilize the advantage of benzoates as “process aids” to speed production rates and improve product quality. J. VINYL. ADDIT. TECHNOL. 11:150–154, 2005. © 2005 Society of Plastics Engineers     

Sorption of Phthalates on Molecularly Imprinted Polymers

Porous beads of styrene divinylbenzene copolymer, S-co-DVB, imprinted with dimethyl phthalate, DMP, were obtained. Two solvents were applied for the formation of pores: n-hexane and n-octane. The sorbents were prepared by membrane emulsification of monomer mixtures containing DMP followed by suspension polymerization. The average diameters of the synthesized beads were 40 µm for beads obtained from mixtures with n-octane, and 30 µm for preparations with n-hexane as solvent. It was shown that almost all monodispersive sorbents were obtained; their SPAN parameter was as small as 0.7–0.9. Sorption properties of evaluated samples varied in relation to the kind of applied reaction mixture. Generally, imprinted materials showed higher sorption capacity towards DMP than their off-template analogues. For the sorbent obtained in the presence of n-octane and with 3 wt.% of DMP, sorption of dimethyl phthalate took the highest value - 89 mg/g. The sorbents imprinted with DMP were checked for sorption of diethyl phthalate, DEP, and dibuthyl phthalate, DBP also. It was shown that sorbability of synthesized materials towards other phthalates was much smaller than for DMP and was not related to the presence of dimethyl phthalate foot prints.     

Plasticizer structure/performance relationships

Plasticizers for poly(vinyl chloride) may be organized into eight chemical families and by seven key performance criteria. Cost-effective general-purpose phthalates provide a base line for comparing all other plasticizers. The wide range of performance characteristics associated with various phthalate isomers substantiates the large proportion of phthalate esters that are utilized as plasticizers. This article summarizes plasticizer structural/performance relationships using quantitative comparisons of cost, plasticizing efficiency, plastisol solvation characteristics, dryblending, volatility, and low temperature performance properties in PVC. Some generalizations are also made concerning structural effects of the alcohol isomers used in the syntheses of the various types of plasticizer esters.     

Soft PVC foams: Study of the gelation,fusion, and foaming processes. II. Adipate,citrate and other types of plasticizers

Plasticized poly(vinyl chloride) (PVC) is one of the most useful polymeric materials on an industrial scale because of its processability, wide range of obtainable properties, and low cost. PVC plastisols are used in the production of flexible PVC foams. Phthalates are the most used plasticizers for PVC, and in a previous article (part I of this series), we discussed the influence of phthalate ester type plasticizers on the foaming process and on the quality of the foams obtained from the corresponding plastisols. Because the use of phthalate plasticizers has been questioned because of possible health implications, the objective of this work was to undertake a similar study with 11 commercial alternative plasticizers to phthalates. The evolution of the dynamic and extensional viscosity and the interactions and thermal transitions undergone by the plastisols during the heating process were studied. Foams were obtained by rotational molding and were characterized by the determination of their thermomechanical properties, density, and cell size distribution. Correlations were obtained between the molecular weight and structure of the plasticizer and the behavior of the corresponding plastisols. After the characterization of the final foamed product, we concluded that foams of relatively good quality could be prepared with alternative plasticizers for replacing phthalates. Several plasticizers {Mesamoll (alkylsulfonic phenyl ester), Eastman 168 [bis(2‐ethylhexyl)‐1,4‐benzenedicarboxylate], Hexamoll [di(isononyl) cyclohexane‐1,2‐dicarboxylate], Citroflex A4 acetyl tributyl citrate (ATBC), and Plastomoll (dihexyl adipate)} were found to be interesting alternatives in the production of soft PVC foams because they provided very good quality foams with properties similar to, or even better than, those obtained with phthalate plasticizers. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Integrated Bioinformatics,Environmental Epidemiologic and Genomic Approaches to Identify Environmental and Molecular Links between Endometriosis and Breast Cancer

We present a combined environmental epidemiologic, genomic, and bioinformatics approach to identify: exposure of environmental chemicals with estrogenic activity; epidemiologic association between endocrine disrupting chemical (EDC) and health effects, such as, breast cancer or endometriosis; and gene-EDC interactions and disease associations. Human exposure measurement and modeling confirmed estrogenic activity of three selected class of environmental chemicals, polychlorinated biphenyls (PCBs), bisphenols (BPs), and phthalates. Meta-analysis showed that PCBs exposure, not Bisphenol A (BPA) and phthalates, increased the summary odds ratio for breast cancer and endometriosis. Bioinformatics analysis of gene-EDC interactions and disease associations identified several hundred genes that were altered by exposure to PCBs, phthalate or BPA. EDCs-modified genes in breast neoplasms and endometriosis are part of steroid hormone signaling and inflammation pathways. All three EDCs–PCB 153, phthalates, and BPA influenced five common genes—CYP19A1, EGFR, ESR2, FOS, and IGF1—in breast cancer as well as in endometriosis. These genes are environmentally and estrogen responsive, altered in human breast and uterine tumors and endometriosis lesions, and part of Mitogen Activated Protein Kinase (MAPK) signaling pathways in cancer. Our findings suggest that breast cancer and endometriosis share some common environmental and molecular risk factors.