Soft PVC Research Articles

In situ formed poly(ε-caprolactone) as a novel non-toxic plasticizer of poly(vinyl chloride)

Poly(vinyl chloride) (PVC) is the third most produced synthetic polymer in the world, irreplaceable in many applications including medical ones. The production of soft PVC presents a problem with volatile low-molecular plasticizers that can be harmful to human health. Therefore, they are often replaced with polymeric plasticizers, which are less effective and require higher processing temperature, however. In this work, we have studied a specific method of PVC plasticization consisting in the mixing of PVC with monomeric ε-caprolactone in a closed system. During thermal treatment of the mixture, in situ polymerization of the ε-caprolactone occurs, initiated by a tin stabilizer of PVC present in the mixture, which results in the formation of poly(ε-caprolactone), a non-toxic and bio-degradable polymeric plasticizer with various molar mass. In this way, a stable plasticized PVC material can be obtained, the thermal stability, softening range and mechanical properties of which correspond to the use of conventional plasticizers.

Quantification of Poly(vinyl chloride) Microplastics via Pressurized Liquid Extraction and Combustion Ion Chromatography

A reliable analytical method has been developed to quantify poly(vinyl chloride) (PVC) in environmental samples. Quantification was conducted via combustion ion chromatography (C-IC). Hydrogen chloride (HCl) was quantitatively released from PVC during thermal decomposition and trapped in an absorption solution. Selectivity of the marker HCl in complex environmental samples was ensured using cleanup via pressurized liquid extraction (PLE) with methanol at 100 °C (discarded) and tetrahydrofuran at 185 °C (collected). Using this method, recoveries of 85.5 ± 11.5% and a limit of quantification down to 8.3 μg/g were achieved. A variety of hard and soft PVC products could be successfully analyzed via C-IC with recoveries exceeding >95%. Furthermore, no measurable overdetermination was found for various organic and inorganic matrix ingredients, such as sodium chloride, sucralose, hydroxychloroquine, diclofenac, chloramphenicol, triclosan, or polychlorinated biphenyls. In addition, sediments and suspended particular matter showed PVC concentrations ranging up to 16.0 and 220 μg/g, respectively. However, the gap between determined polymer mass and particle masses could be significant since soft PVC products contain plasticizers up to 50 wt %. Hence, the results of the described method represent a sum of all chlorine-containing polymers, which are extractable under the chosen conditions.

Non-persistent chemicals in polymer and non-polymer products can cause persistent environmental contamination: evidence with DEHP in Europe.

Bis(2-ethylhexyl) phthalate (DEHP) is a plasticizer that has been massively used since the second part of the twentieth century by the plastic industry to provide softness properties to PVC. This chemical is considered as toxic to reproduction and endocrine disrupting, and a wide range of uses are now forbidden by the EU. Despite these regulations, DEHP is still found to be a widespread contaminant in watersheds in the EU. In this study, we calculate retrospective and prospective scenarios of past and future emissions of DEHP in the environment (water, soil, air) in the EU 28, taking into account the entire lifecycle of the substance, from its production and its inclusion in polymer (mainly PVC) and non-polymer products (adhesive and sealant, ceramic and printing ink) to the recycling and end of life of these products. We develop a stock and flow model based on dynamically estimating the stocks of DEHP present in products on the market. Our results show that the introduction of recent regulations to limit the use of DEHP (that bring a 70% reduction of DEHP contained in products placed on the market in 2020 and 75% in 2040) will not reduce significantly future emissions. This persistence of emissions is explained by the high stocks built in the economy and the long-term presence of soft PVC waste in landfills. Our results suggest that DEHP will remain a cause of environmental contamination many decades after uses have declined and even ceased, and it appears to be too late for market regulation at the market stage to offset the effect of past stock buildup and landfilling. It is likely that several chemicals that are not considered as persistent and therefore not the focus of international regulations could exhibit the same characteristics. Regulations should avoid possible use patterns that make hazardous chemicals persistent in products, because they have the potential to create long-term and almost irreversible environmental pollution and impacts.

Effects of plasticizing time on flexural fatigue of soft Poly(vinyl chloride)

In this study, seven gradient plasticizing time at 200°C were set to explore the effects on Bally Flex fatigue of soft poly(vinyl chloride) (PVC). The results showed that the rotational rheometer was well used to characterize the plasticizing process of PVC paste. The optimum plasticizing temperature of soft PVC was about 180°C. Within a certain range of plasticizing time, the glass transition temperature of soft PVC decreased with the extension of plasticizing time, and the Bally Flex fatigue life was prolonged as the plasticizing time extended. When the plasticizing time was 105 s, the plasticization was nearly completed, which can be used as an optimum plasticizing time in terms of manufacturing efficiency and quality. When the plasticization time was 135 s, the degree of plasticization was the highest. The fatigue cycles of Bally Flex and breaking energy (W) at −20°C were 136,000 and 4850 J·m−3, respectively. It was concluded that Bally Flex fatigue life and W had a good positive correlation. Thus, the tensile test can be used as a simple approach to predict the Bally Flex fatigue life trend of soft PVC specimens.

Modified silica to strengthening and toughening soft polyvinyl chloride

AbstractModifying nanoparticles for polymer nanocomposites is important for multifunctional and low‐cost developmental direction. However, nanoparticles have several deficiencies, such as dispersion, agglomeration, and poor binding ability with most polymers. This work used soft polyvinyl chloride (PVC with 33.1% plasticizer volume) as the matrix. Polycaprolactone (PCL) was synthesized on the surface of SiO2 by the bridging effect of silane coupling agent (SiO2‐PCL), which was expected to improve the bond strength between SiO2 and soft PVC matrix. Moreover, it enhanced the dispersion of SiO2 in the PVC matrix. The results revealed that SiO2‐PCL was nanodispersed in a soft PVC matrix and played a plasticizer role in the composite, which enhanced the tensile strength and elongation at break of PVC composites. The thermal stability and solvent extraction stability of PVC composites elevated with the increase of SiO2‐PCL content. When the content of SiO2‐PCL was 8 wt%, the tensile strength (14.54 MPa) and elongation at break (149.47%) of PVC composites were the highest, 64.36% and 60.48% higher than those of unfilled PVC, respectively. It was indicated that PVC composites were dramatically toughened and strengthened by modified SiO2, improving their overall performance.

Curcumin-loaded magnetic chitosan-based solid-phase extraction-gas chromatography of migrated phthalate esters from pacifiers and plastic toys into baby saliva

The aim of this study was to investigate the presence of phthalate esters in the saliva of babies who use pacifiers or plastic toys mouthed by them. For this purpose, magnetic micro solid-phase extraction coupled with gas chromatography equipped with a flame ionization detector (GC–FID) was developed. The solid sorbent, curcumin loaded magnetic chitosan (CUR-MCH), successfully synthesized and characterized by FT-IR, FESEM, TEM and VSM. Parameters affecting the extraction efficiency are monitored and optimized through the univariate analysis and experimental design. Under optimum conditions, method presented good linearity [in the range 0.001–5 µg mL−1 for dimethyl phthalate (DMP), din-butyl phthalate (DBP), benzyl butyl phthalate (BBP) and di(2-ethylhexyl) (DEHP)] with coefficient of determination (R2) from 0.9823 to 0.9935 and enrichment factors from 38 to 50. The applicability of the method was examined using real samples from baby's saliva. Saliva samples are collected, extraction procedure performed on them, resultant of extraction injected to GC for separation and quantification of phthalate esters. The results of this study showed that baby accessories made of soft PVC emit phthalate species and contaminate baby's saliva. Among the phthalate species studied, DBP and DEHP are released from polymers more than other species and enter saliva and then the baby's body. Probably more of these two species have been used in the production of these products. Of course, the child's age and ability to chew plastic also play a role.

Effective, Environmentally Friendly PVC Plasticizers Based on Succinic Acid.

The plasticizers used in this study were synthesized from renewable raw materials using succinic acid, oleic acid, and propylene glycol. Four environmentally friendly plasticizer samples were obtained; their chemical structures and compositions were confirmed by gas chromatography (GC) and infrared spectroscopy (FT–IR) analyses, and their physicochemical properties and thermal stability (TGA analysis) were investigated. The obtained ester mixtures were used as poly(vinyl chloride) (PVC) plasticizers and their plasticization efficiency was determined in comparison to traditional, commercially available phthalate plasticizers, such as DEHP (di(2-ethylhexyl phthalate) and DINP (diisononyl phthalate). Mechanical properties and migration resistance were determined for soft PVC with the use of three concentrations of plasticizers (40 PHR, 50 PHR, and 60 PHR). It was observed that the obtained plasticizers exhibited the same plasticization efficiency and were characterized with good mechanical and physical properties in comparison to commercial plasticizers. The tensile strength was approx. 19 MPa, while the elongation at break was approx. 250% for all tested plasticizers at a concentration of 50 PHR. Furthermore, plasticizer migration studies showed that the synthesized plasticizers had excellent resistance to plasticizer leaching. The best migration test result obtained was 70% lower than that for DEHP or DINP. The ester mixture that was found to be the most favorable plasticizer was characterized by good thermal and thermo-oxidative stability (5% weight loss temperature: 227.8 °C in air and 261.1 °C in nitrogen). The results of the research clearly indicate that the synthesized esters can provide a green alternative to toxic phthalate plasticizers.

Enhancing of broadband sound absorption through soft matter.

This paper proposed a metamaterial design method that uses soft matter for constructing a unique soft acoustic boundary to effectively improve broadband sound absorption performance. Specifically, attaching a flexible polyvinyl chloride (PVC) gel layer with an elastic modulus as low as a few kilopascals and a thickness of a few millimeters to the inner wall of a cavity-type sound-absorbing metamaterial structure significantly improved the absorption performance of the composite structure in low-frequency broadband ranges. The sound absorption enhancement mechanism differed from those proposed in previous research. On the one hand, the soft PVC gel layer acted as a soft acoustic boundary, substantially reducing the sound speed and reflection and producing considerable elastic strain energy at the interface between two different media to improve the sound absorption performance. On the other hand, this PVC gel layer displayed extremely low stiffness and high damping, producing an abundance of plasmon-like resonance modes in low-frequency broadband ranges, achieving a resonance absorption effect. Since this sound absorption enhancement method did not require an increase in the external dimensions or a change in the structural parameters of the original absorber and achieved robust enhancement in a wide frequency band, it displayed potential application value in various engineering fields.

Influences of plasticizer molecular structure and content on flexural fatigue of soft poly(vinyl chloride)

AbstractIn this work, three plasticizers with different molecular structures were used to plasticize poly(vinyl chloride) (PVC), and the influence of different plasticizers on the flexural fatigue properties of soft PVC was investigated. The plasticizer with the best plasticizing effect was selected, and five gradient dosages were set to study the optimal ratio of plasticizer and PVC. It was found that the glass transition temperature of samples with two phthalate plasticizers (DPHP, 1012P) was lower than that with trimellitate plasticizer (TM‐8). It has excellent low‐temperature mechanical properties and great flexural fatigue resistance. From the comparison of different plasticizer gradient formulations, the glass transition temperature, PVC plastisol viscosity, and melt strength decreased gradually with the increase of plasticizers. When PVC and plasticizer were 1:1 (PVC50P50), the plasticizing effect and the low‐temperature toughness of the sample were the best. The breaking energy (W) and fatigue cycles of Bally Flex at −20°C were 5173 J m−3 and 141 000, respectively. It was concluded that W and Bally Flex fatigue life have a good positive correlation n. Thus, tensile test can be simply used to predict Bally Flex fatigue life of samples.

Preparation and properties of transparent powder filled soft poly(vinyl chloride) composite film with high transparency

AbstractIn this study, transparent powder (TP) with a refractive index similar to that of poly(vinyl chloride) (PVC) was used as inorganic filler to prepare PVC composite film with high transparency. TP was modified with γ‐methylacryloxypropyl trimethoxy silane (KH570) and characterized by Fourier transform infrared spectroscopy, X‐ray diffraction, and Zeta potential analysis. Then, KH570 modified TP was incorporated into PVC, and its effects on the mechanical, transparent, and thermal properties of soft PVC composite film were investigated by tensile test, transmittance measurement and thermogravimetric analysis. The results show that the optimum loading of modified TP is 7.5 phr (mass), at which the breaking strength (18.5 MPa) and elongation at break (669.5%) of the composite film are 60.9% and 54.0% higher than that of pure PVC film, respectively. The highest light transmittance is 85.6% at a filler loading of 5 phr. Thus, TP filled PVC composite film has excellent mechanical transparent properties and high transparency.

Biobased Plasticizers from Tartaric Acid: Synthesis and Effect of Alkyl Chain Length on the Properties of Poly(vinyl chloride).

A series of tartaric acid (TA) esters with different side chain lengths [dibutyl TA esters (DBTAE)-Cn], as plasticizers for poly(vinyl chloride) (PVC), is herein reported. Their structures have been fully characterized using proton nuclear magnetic resonance and Fourier-transform infrared spectroscopy. Their compatibility and plasticizing effect for soft PVC were evaluated using thermogravimetric analysis, dynamic mechanical analysis, tensile testing, and migration testing. The results showed that all these TA esters exhibit good plasticizing performance. At a concentration of 30 phr in PVC, the best results for the plasticizing effect, in terms of glass transition temperature reduction and elongation at break, were achieved when the ester DBTAE-C4 was used. However, the longer side chains of these esters improved the thermal stability of soft PVC blends yet exacerbated the migration behavior of these esters from PVC films in n-hexane. The properties of the plasticized PVC blends depended on the structural features of DBTAE-Cn. The plasticizing performances of the esters DBTAE-C1 and DBTAE-C4 rivaled that of dioctyl phthalate (DOP), suggesting that they have the potential to replace DOP in soft PVC materials.

Costs and benefits of recycling PVC contaminated with the legacy hazardous plasticizer DEHP.

Reusing materials is an attractive option for circular economy and can also reduce emissions of greenhouse gases and pollutants. However, recycling raises questions regarding the potential risks to human health or the environment when hazardous legacy chemical additives of materials are also recycled, instead of the recent and less hazardous additives of virgin materials. To address this trade-off, this study developed a model to calculate the total external cost of material supply, considering the health and environmental impacts of all industrial steps (e.g. virgin material production, incineration, and recycling), and the health effects of recycling chemicals present in the material. The model is coupling material flow analysis, life-cycle analysis, and environmental economics to compare different recycling policies. It is applied for all illustrative purposes to soft PVC and DEHP in France. Results show that recycling of materials is in the long-term positive despite the prolongation of the presence of hazardous additives in materials. The time when the recurring environmental benefits of recycling offset the negative impacts on human health of recycling the additives is very sensitive to the health impact of additives. This approach can improve the harmonization between recycling and circular economy policies, and as a framework to confirm the relevance and size treatments to remove additives from materials during recycling.

Influences of processing conditions on the glass transition of soft poly(vinyl chloride) compounds filled with calcium carbonate

Three series of soft polyvinyl chloride (soft PVC) compounds were prepared at different processing conditions during PVC powder mixing. The processing conditions varied in two different adding procedures of calcium carbonate (CaCO3) powder, two discharge temperatures and two mixing frequencies. The influences of the processing conditions on the glass transition of soft PVC compounds filled with calcium carbonate were extensively investigated by using differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and scanning electron microscope (SEM) associated with energy-dispersive X-ray spectroscopy (EDS). It was found that, under the combinative conditions of addition of CaCO3 powder using the one-step procedure instead of two-step procedure, increase of discharge temperature or use of higher mixing frequency, the glass transition of plasticized PVC component could shift to lower temperatures for soft PVC compounds. Under the same formulas, the one-step procedure was confirmed to be preferred, since two separated glass transitions were detected in DSC measurements of the samples prepared by the two-step procedure, where the higher glass transition corresponded to the less plasticized PVC component due to worse mixing efficiency. This finding is quite helpful for the preparation of soft PVC compounds with lower glass transition temperatures.

Analysis of the dependence of stresses and deformations on the surfaces of shoe soles of different thicknesses and materials

For this study, three-dimensional models of the soles of work shoes of different thicknesses and consisting of different materials were created. These models were analyzed to obtain the distribution of stress and strain on their surfaces. To build the model, we used experimental data on the shape and size of the sole, as well as the properties of specific materials used in the manufacture of soles for work shoes used in agriculture. The goal was to determine the most suitable material, that is, which of the materials has the most suitable characteristics for the sole, has the best wear resistance when used in agriculture. We noticed a significant reduction in deformations on the surface of the sole with an increase in the thickness of the sole, as well as when using two-component casting of the sole from a combination of materials: low-density EVA and flexible PU, medium-density EVA and soft PVC. This indicates their advantages and maximum suitability.

Effects of polyether titanate coupling agent on the flame retardancy and mechanical properties of soft poly(vinyl chloride)/basic magnesium carbonate composites

AbstractIn this paper, a new polyether titanate coupling agent (Ti4000) was used to modify basic magnesium carbonate (BMC), and Ti4000 modified BMC (Ti4000‐BMC) was characterized by X‐ray powder diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and X‐ray photoelectron spectroscopy. Then, PVC composites were prepared by adding BMC or Ti4000‐BMC into soft PVC matrix via melt blending, and their flame retardancy was examined by limiting oxygen index (LOI), UL‐94 test, and cone calorimeter test. The results show that BMC can effectively improve flame resistance and suppress smoke production of pure soft PVC. As a result, the LOI is increased from 23.9% for pure soft PVC to 29.2% for Ti4000‐BMC/PVC composite with 50 phr Ti4000‐BMC (50%Ti4000‐BMC/PVC), and the composite passes the V0 rating in UL‐94 test, the peak heat release rate, total heat release, peak smoke production rate, and total smoke production are decreased from 343.10 kW/m2, 94.50 MJ/m2, 0.17 m2/s, and 27.20 m2/kg for pure soft PVC to 234.20 kW/m2, 70.20 MJ/m2, 0.02 m2/s, and 2.30 m2/kg for 50%Ti4000‐BMC/PVC composite, respectively. The analysis of char residues suggests that Ti4000‐BMC/PVC composites form the most compact char layer structure, indicating that the soft PVC composites show better char forming ability. In addition, the yield strength is increased from 4.4 MPa for pure soft PVC to 12.9 MPa for 50%Ti4000‐BMC/PVC composite, with an increase of 193.2%, and it shows good reinforcement effect on the soft PVC matrix.

Compression behavior of soft PVC foams obtained by cardanol-derived plasticizer

This work is aimed to study the application of a bio-based plasticizer, obtained by acetylation and epoxydation of cardanol, for the production of soft PVC foams. The use of epoxidized cardanol acetate allowed obtaining a more efficient foaming of soft PVC compared to phthalate plasticizer bis(2-ethylhexyl) phthalate (DEHP), mainly due to the lower viscosity attained in the decomposition range of azodicarbonamide (AZDC). As a consequence, the foams produced by epoxidized cardanol acetate showed a lower density compared to those produced with DEHP. The lower density yielded lower values of compressive modulus. However, the modulus was shown to be not only dependent on the density, but also showed a direct dependence on the type of plasticizer used, in addition to processing temperature and AZDC content. As a consequence, the specific compressive modulus also showed a direct dependence on the type of plasticizer, processing temperature and AZDC content. Such dependence was explained by considering different cellular morphologies developed during foaming under different processing conditions, including type of plasticizer. In particular, it was shown that the lower viscosity attained by epoxidized cardanol acetate plasticized PVC involved an increase of the average pore size of the foam, which was shown to be the main cause of the variation of the specific compressive modulus.

Synthesis of a Novel Bio-Oil-Based Hyperbranched Ester Plasticizer and Its Effects on Poly(vinyl chloride) Soft Films.

A novel hyperbranched ester plasticizer (SOHE) was synthesized from soybean oil. FTIR, 1H NMR, and 13C NMR spectroscopies were used to analyze the chemical structure of SOHE. SOHE was added into poly(vinyl chloride) (PVC). Thermal, mechanical, and dynamic mechanical properties of PVC samples were studied with thermal gravimetric analysis, dynamic mechanical analysis, and tensile tests. The results of SOHE substitution of petroleum-based dioctyl phthalate (DOP) in soft PVC samples were studied. The results indicated that PVC blends mixed with the obtained plasticizer showed higher thermal stability and flexibility. When DOP was completely replaced with SOHE, the Ti, T10, and T50 of the films were raised to 267.5, 275.3, and 338.0 °C, respectively. The plasticizing mechanism was also investigated. The volatility resistance and extraction were studied, which results indicated that the migration stability of PVC samples was significantly enhanced with the increasing amount of SOHE.

Flexible Vibrotactile Actuator Based on Soft PVC Gel Embedded Polyaniline/Silicon Dioxide Nanoparticles

Nanocomposite hybrid materials made of inorganic nanoparticles and organic polymers are fascinating to design high performance polymeric materials, customized in electronics and transportation sectors. In this concern, a soft and flexible PVC gel embedded with silicon dioxide nanoparticles (SDNs) coated with polyaniline (PANI) has been proposed as a dielectric interface in vibrotactile actuator. Soft PVC gels were achieved by plasticization using acetyltributylcitrate (ATBC), an ecofriendly green plasticizer. The optimization of plasticizer content to PVC was precisely controlled and the ratio was kept constant throughout the experiment. PANI was coated on SDN by using chemical oxidative polymerization technique in order to tune the dielectric/electronic properties and minimize the leakage current. Various quantities of PANI-SDNs were loaded to PVC; the behavior of nanocomposite PVC gels as soft vibrotactile actuators was investigated. All the composite materials were comprehensively investigated using different physico-chemical techniques and haptic performance of the optimized PANI-SDN-0.2 nanocomposite PVC gel was assessed. The following are available online at http://www.xxx.com/xxx/s1, Figure S1. Pictograph representing PANI-SDN-0.2 nanocomposite PVC gel, (a) a flat PANI-SDN-0.2 nanocomposite PVC gel, (b) demonstrating the flexibility of PANI-SDN-0.2 nanocomposite PVC gel, (c) a wavy-shaped PANI-SDN-0.2 nanocomposite PVC gel for actuator design (d) dimensions of the fabricated wavy-shaped PANI-SDN nanocomposite PVC gels. Figure S2. Illustration to demonstrate the fabrication process of the vibrotactile actuator (a) components of the vibrotactile actuator, (b) lower surface of the top layer, (c) assembled vibrotactile actuator, (d) cross-sectional image of the vibrotactile actuator. Figure S3. Experimental environment demonstrating the measurement of haptic performance of PANI-SDN nanocomposite PVC gels. Description: Instrumentation and Characterization Techniques. Figure S4. EDX spectra of PANI (Scale = 1 μm). Figure S5. EDX spectra of SDNs (Scale = 1 μm). Figure S6. EDX spectra of PANI-SDNs (Scale = 1 μm). Figure S7. EDX spectra of PANI-SDN-0.2 nanocomposite PVC gel (Scale = 1 μm). Figure S8. (a & b) FESEM micrographs of PANI-SDN-0.2 nanocomposite PVC gel with different magnitudes (Scale = 2 μm and 200 nm respectively). Figure S9. Acceleration performance of PANI-SDN-0.01, PANI-SDN-0.05, PANI-SDN-0.1, PANI-SDN-0.3, PANI-SDN-0.4 and PANI-SDN-0.5 nanocomposite PVC gel based actuators.

Effect of liquid plasticizers on crystallization of PCL in soft PVC/PCL/plasticizer blends

ABSTRACTIn this work, poly(ε‐caprolactone) (PCL) and liquid plasticizer were combined used to plasticize poly(vinyl chloride) (PVC), and the possibility of using PVC/PCL/plasticizer blends to fabricate soft PVC with enhanced migration resistance was investigated. Through partial replacement of liquid plasticizers in soft PVC by equal quantity of PCL, flexibility was maintained while extraction loss of plasticizer by organic solvent was reduced significantly. Furthermore, crystallization of PCL in PVC/PCL/plasticizer blends with low PCL content was observed, and crystallization rate of PCL was found to be influenced by plasticizer contents and structures. For instance, crystallization rate of PCL in PVC/PCL/diisononyl phthalate (DINP) (100/40/100) was 3.7 times faster than in PVC/PCL/DINP (100/40/80), while crystallization rate of PCL in PVC/PCL/dioctyl adipate(DOA)(100/40/100) was 8.3 times faster than in PVC/PCL/diisononyl cyclohexane‐1,2‐dicarboxylate (DINCH) (100/40/100). Low‐field 1H NMR test manifested that different crystallization rate of PCL in PVC/PCL/plasticizer blends with different plasticizer structures was triggered by difference in plasticizers' compatibility with PVC, that is, the number of interaction point between PVC and plasticizers. It is concluded that PCL crystallization favored by liquid plasticizers in PVC/PCL/plasticizer blends was induced by interaction competition between PVC/plasticizer and PVC/PCL. As plasticizer content increases or its compatibility with PVC decreases, interaction competition becomes more intense and consequently faster crystallization of PCL occurs. Thus, to obtain soft PVC products with improve migration resistance while avoiding PCL crystallization, the total content of plasticizer (including both liquid plasticizer and PCL) should be lower than 66 phr (40 wt %). © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48803.

Safety assessment of the substance trimellitic acid, tris (2-ethylhexyl) ester, for use in food contact materials.

This scientific opinion of the EFSA Panel on Food Contact Materials, Enzymes and Processing aids (CEP Panel) is on the safety assessment of trimellitic acid, tris(2‐ethylhexyl) ester, intended to be used as a plasticiser in the manufacture of soft poly(vinyl chloride) (PVC) materials and articles, such as wrap films (single uses) and tubing (repeated uses) at up to approximately 10% and 40%, respectively. Under the tested conditions, the substance migrated up to 165 μg/kg food from wrap films and was not detected in food simulant in contact with tubing. Based on the three reported in vitro genotoxicity studies, the Panel concluded that the substance does not raise concern for genotoxicity. The lowest no observed adverse effect level (NOAEL), derived from a 90‐day oral toxicity study, was 225 mg/kg body weight (bw) per day. Based on data on toxicokinetic and metabolism, the substance does not give rise to concern for accumulation in humans. The substance does not cause developmental effects as induced by phthalic acid, bis(2‐ethylhexyl) ester (DEHP). Assuming that impurities migrate pro‐rata to a migration of the substance up to 5 mg/kg food, their estimated migration does not raise a safety concern. The Panel concluded that the substance does not raise safety concern for the consumer when used in the manufacture of soft PVC under the conditions requested by the applicant for (i) single use wrap films in contact with food for which simulants A, B and D1 are assigned, as well as (ii) tubing for repeated contacts with food for which simulants A and B are assigned. Overall, the use of the substance does not raise a safety concern if its migration does not exceed 5 mg/kg food. Due to the additional contribution from other sources of exposures, the application of an allocation factor should be considered.