Absorption and migration of bio‐based epoxidized soybean oil and its mixtures with tri(2‐ethylhexyl) trimellitate in poly(vinylchloride)

The efficacy of epoxidized soybean oil (ESO), tri(2‐ethylhexyl) trimellitate, and mixtures thereof as plasticizers for poly(vinylchloride) has been studied. At 80°C, the trimellitate was slower to absorb in this polymer than ESO and was also less soluble, but the former exhibited higher solubility at 120°C. Plasticization efficiencies of stabilized polymeric compositions were similar with ESO and the trimellitate (despite their very different molecular weights). The trimellitate yielded greater mass loss during heat aging of the plasticized compositions, but substituting even minor amounts of it with ESO decreased mass loss synergistically. The trimellitate also resulted in more of an increase in hardness than ESO over time at elevated temperatures, but when aged at 120°C, mixtures of the two surprisingly had more deleterious effects. Thus, although ESO can replace part or all of trimellitates in plasticized PVC, using it as sole plasticizer would be preferable when heat aging performance is a requirement. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41966.     

Evaluating effects of biobased 2,5‐furandicarboxylate esters as plasticizers on the thermal and mechanical properties of poly (vinyl chloride)

We synthesized 2,5‐furandicarboxylate esters [i.e., dibutylfuran‐2,5‐dicarboxylate, diisoamylfuran‐2,5‐dicarboxylate, and di(2‐ethylhexyl)furan‐2,5‐dicarboxylate] and investigated their potential application as plasticizers of commercial poly(vinyl chloride) (PVC) products. Fourier transform infrared analysis, mechanical tests, scanning electron microscopy investigation, differential scanning calorimetry analysis, dynamic mechanical thermal analysis, thermogravimetric analysis (TGA), melt flow rate (MFR) measurement, and plasticizer migration measurements were used to the evaluate the comprehensive properties of the blended products. The results of the tensile tests demonstrate that the blends exhibited antiplasticization and flexible plastic characteristics at 10 and 50 phr in PVC, respectively. Moreover, flexural and impact test data indicate that the three types of blends exhibited a similar tendency: the hardness decreased continuously as the amount of plasticizer increased. Their morphology indicated that all of the plasticizers had good compatibility with PVC. The resulting glass‐transition temperature of the investigated plasticizers was lower than that of pure PVC, and reduction was largest for the plasticizer with the highest molecular weight. TGA revealed that the thermal degradation of blended polymers occurred in three stages and that all of the blends were stable up to 180°C. Finally, the MFRs of all of the specimens indicated that the addition of a higher concentration of lower molecular weight biobased esters resulted in improved fluidity, but these compounds migrated more easily from the blends. Hence, 2,5‐furandicarboxylic acid derived from biomass has potential as a plasticizer. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40938.     

A new biobased plasticizer for poly(vinyl chloride) based on epoxidized cottonseed oil

The use of epoxidized cottonseed oil as plasticizer for poly(vinyl chloride) was studied. The plasticizer content was set to 70 phr and the optimum isothermal curing conditions were studied in the temperature range comprised between 160 and 220 °C with varying curing times in the 7.5–17.5 min range. The influence of the curing conditions on overall performance of cured plastisols was followed by the evolution of mechanical properties (tensile tests with measurements of tensile strength, elongation at break, and modulus), change in color, surface changes of fractured samples by scanning electron microscopy (SEM), thermal transitions by differential scanning calorimetry, and migration in n‐hexane. The optimum mechanical features of cured plastisols are obtained for curing temperatures in the 190–220 °C range. For these curing conditions, fractography analysis by SEM gives evidences of full curing process as no PVC particles and free plasticizer can be found. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43642.     

Copolyesters as non‐toxic plasticizers

Plasticized polymer materials have taken an enormous role in our everyday life. Most of the common plasticizers are aromatics, esters of phthalic acid. Since they are not chemically bonded to the polymer matrix, they can be released from material while being used. The concerns raised about toxicity led to a large demand for producing biodegradable and non‐toxic plasticizers. We investigated aliphatic copolyesters synthesized via ring opening polymerization of lactones as plasticizers for poly(vinyl chloride). The material properties of the formulations, such as glass transition temperature and mechanical performance, were studied. Copyright © 2011 Society of Chemical Industry     

Environmentally friendly plasticizers for poly(vinyl chloride)—Improved mechanical properties and compatibility by using branched poly(butylene adipate) as a polymeric plasticizer

Linear and branched poly(butylene adipate)s (PBA) with molecular weights ranging from 2000 to 10,000 g/mol, and a branching agent content between 0 and 1.8%, were solution cast with poly(vinyl chloride) (PVC) to form 50‐ to 60‐μm thick flexible films. Dry films were analyzed by tensile testing, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and optical microscopy (OM) to study the effects of molecular weight and branching on the plasticizing efficiency of the polyester. PBA formed a semimiscible two‐phase system with PVC, where the amorphous part exhibited a single glass transition temperature. The degree of crystallinity for the polyester, surface composition, and mechanical properties of the films depended on the blend composition, molecular weight, and degree of branching of the polyester. Plasticizing efficiency was improved by higher degree of branching. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2180–2188, 2006     

Preparation and application of triglyceride plasticizers for poly(vinyl chloride)

A series of triglyceride plasticizers were prepared from glycerol, acetic acid, and benzoic acid through a two‐step reaction to develop potential uses of glycerol. The optimum reaction conditions were determined by the esterification of glycerol and acetic acid to produce glyceryl triacetate. When the molar ratio of glycerol to benzoic acid to acetic acid was 1:1:3.5, a novel plasticizer triglyceride mixture (GTM) was successfully synthesized; it had a good plasticizing effect on poly(vinyl chloride) (PVC). The elongation at break of PVC composites containing 80 phr GTM increased around 350%; the corresponding hardness (Shore D) and tensile strength decreased to around 35 D and 20 MPa, respectively. Moreover, the glass‐transition temperature (T_g) of PVC composites containing 40 phr GTM decreased to around 50°C. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Diester based on castor oil fatty acid as plasticizer for poly(vinyl chloride)

Castor oil is a renewable resource that has potential uses as an environmental friendly material for a range of applications. In recent years, much efforts have been driven to develop alternate plasticizer for medical and commodity plastics due to growing concerns about dioctyl phthalate (DOP) for flexible poly(vinyl chloride) (PVC). In this study, a bio‐based plasticizer was synthesized by a two‐step esterification reaction of castor oil fatty acid (COFA) with benzyl alcohol and octanoic acid in the presence of catalyst (dibutyl tin dilaurate). The structure of the octanoic ester (OE) was confirmed by proton nuclear magnetic resonance, Fourier transform infrared spectroscopy, acid value, and hydroxyl value. OE was used as a coplasticizer in PVC for partial replacement of DOP. The addition of OE exhibited good incorporation and plasticizing performance in the PVC sheets. Incorporation of OE resulted in good plasticizing, tensile strength, percentage elongation, exudation, thermal stability, and chemical resistance because of the presence of long carbon chains of COFA. Differential scanning calorimetry (DSC), thermogravimetric analysis, and color measurements were also performed to evaluate the effect of OE. With the increase in OE, DSC and hardness results showed marginal deviation from those obtained for DOP‐plasticized sheets. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40354.     

Stabilization of epoxidized soybean oil‐plasticized poly(vinyl chloride) blends via thermal curing with genistein

In an effort to alleviate the well‐known toxicity effect of phthalate derivatives on human health, genistein (G) modified epoxidized soybean oil (ESBO) has been investigated as an alternative “green” plasticizer for poly(vinyl chloride) (PVC) with potential application in medical products. As evidenced by a single glass transition that shifts systematically with composition in conjunction with the melting point depression of G crystals, ESBO is not only a good plasticizer to PVC, but also miscible with G. Moreover, ESBO is an excellent compatibilizer to the immiscible PVC/G pair. Furthermore, PVC/ESBO/G ternary blends revealed complete miscibility in the amorphous state. Of particular interest is that ESBO‐plasticized PVC is thermally curable with G at elevated temperatures above 220 °C and affords relatively stable G modified ESBO‐plasticized PVC for blood contact medical applications such as blood bags and hemodialysis tubings. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46472.     

Ester‐amide based on ricinoleic acid as a novel primary plasticizer for poly(vinyl chloride)

Utilization of ricinoleic acid as a raw material for the synthesis of green plasticizer would offer an alternative to the phthalate plasticizers. Ester‐amide of ricinoleic acid was synthesized by a two‐step reaction with dibutyl amine and benzoic acid; and then utilized as primary plasticizer in PVC. Ester‐amide plasticizer was added up to 40 phr in PVC; and the prepared PVC sheets were characterized for mechanical, X‐ray diffraction, thermal, rheological, colorimetric, and exudation properties. Addition of the ester‐amide plasticizer demonstrated good incorporation and plasticizing performance in PVC. Viscosity of PVC decreased with increased addition of ester‐amide plasticizer. The dark color of the synthesized plasticizer could have constraints on its application areas; however, the prepared samples illustrated negligible weight loss in the exudation test, attributed to better compatibility between them brought about by the ester, tertiary amide and polarizable benzene ring in the ester‐amide plasticizer with the C‐Cl polar linkage in PVC. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41913.     

Preparation of chlorinated poly(vinyl chloride)‐g‐poly(N‐vinyl‐2‐pyrrolidinone) membranes and their water permeation properties

Chlorinated poly(vinyl chloride) (CPVC) membranes for microfiltration processes were prepared with the combined process of a solvent evaporation technique and the water‐vapor induced‐phase‐inversion method. CPVC membranes with a mean pore size of 0.7 μm were very hydrophobic. These membranes were subjected to surface modification by ultraviolet (UV)‐assisted graft polymerization with N‐vinyl‐2‐pyrrolidinone (NVP) to increase their surface wettability and decrease their adsorptive fouling. The grafting yields of the modified membranes were controlled by alteration of UV irradiation time and NVP monomer concentration. The changes in chemical structure between the CPVC membrane and the CPVC‐g‐poly(N‐vinyl‐2‐pyrrolidinone) membrane and the variation of the topologies of the modified PVC membranes were characterized by Fourier transform infrared spectroscopy, gel permeation chromatography, and field emission scanning electron microscopy. According to the results, the graft yield of the modified CPVC membrane reached a maximum at 5 min of UV exposure time and 20 vol % NVP concentration. The filtration behavior of these membranes was investigated with deionized water by a crossflow filtration measurement. The surface hydrophilicity and roughness were easily changed by the grafting of NVP on the surface of the CPVC membrane through a simultaneous irradiation grafting method by UV irradiation. To confirm the effect of grafting for filtration, we compared the unmodified and modified CPVC membranes with respect to their deionized water permeation by using crossflow filtration methods. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 3188–3195, 2003     

Synthesis and application of an alternative plasticizer Di(2‐Ethylhexyl)‐1,2‐cyclohexane dicarboxylate

Cyclohexane dicarboxylic acid esters are environmentally friendly and non‐toxic plasticizers, and have similar performance with phthalates which have potential toxicity to human health. In this article, di(2‐ethylhexyl)‐1,2‐cyclohexane dicarboxylate (DEHCH) was synthesized via esterification between hexahydrophthalic anhydride (HHPA) with iso‐octanol by using concentrated sulfuric acid as a catalyst. The effects of reaction parameters on esterification were studied by investigating the temperature, reaction time, molar ratio of iso‐octanol‐to‐HHPA, and catalyst content. Conversions of HHPA to esters were determined. Functional group analysis was conducted by using FTIR and ¹H‐NMR spectroscopy. PVC compounds after addition of the synthesized plasticizer DEHCH presented similar plasticizing performance with DEHP and DINCH, as demonstrated by comparisons of the results of mechanical properties, transparency, and volatilization and migration tests obtained for plasticized PVC compounds. DEHCH can also be considered as an alternative plasticizer for DEHP. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39763.     

Design and synthesis of HFCA-based plasticizers with asymmetrical alkyl chains for poly(vinyl chloride)

A series of bio-based diester plasticizers with various alkyl chain asymmetry and the same molecular weight were designed and synthesized, using renewable 5-hydroxymethyl-2-furancarboxylic acid (HFCA) as the raw material. The chemical structures of the HFCA-based plasticizers were characterized by Fourier transform infrared and nuclear magnetic resonance (¹H NMR and ¹³C NMR). Besides, the influence of alkyl chain asymmetry on plasticization properties of the HFCA-based plasticizers in poly(vinyl chloride) (PVC) blends was also investigated. It was found that increasing the alkyl chain asymmetry of the diester plasticizer and keeping the molecular weight unchanged simultaneously could further improve its plasticizing efficiency, without sacrificing its volatility resistance and exudation resistance. The results showed that this study provided a new approach for further optimizing the overall properties of the asymmetric diester plasticizers.     

Synthesis and application of a novel cardanol‐based plasticizer as secondary or main plasticizer for poly(vinyl chloride)

A novel plasticizer based on cardanol, hydrogenated cardanol glycidyl ether acetic ester containing phosphaphenanthrene group (HCGEP), was prepared and incorporated into poly(vinyl chloride) (PVC) for the first time. The molecular structure was characterized with Fourier transform infrared and ¹H NMR spectroscopies. The thermal degradation behavior and flame retardant performance of PVC films with HCGEP as secondary or main plasticizer were investigated using thermogravimetric analysis, combustion tests, limiting oxygen index tests and morphological analysis of residues. Furthermore, the mechanical properties of PVC films were examined based on the results of tensile testing. The results were compared to those of the petroleum‐based plasticizer dioctyl phthalate. With the substitution of dioctyl phthalate with HCGEP, PVC films exhibited high thermal stability and better flame retardant performance. The tensile test results showed that the addition of HCGEP could endow PVC resin with well‐balanced properties of flexibility, strength and hardness. © 2017 Society of Chemical Industry     

Synthesis and evaluation of dioctyl 2,5-thiophenedicarboxylate as a potentially bio-based plasticizer for poly(vinyl chloride)

In this work, dioctyl 2,5-thiophenedicarboxylate (DOT), a potentially bio-based plasticizer, was synthesized and evaluated as an alternative to traditional petroleum-based plasticizers. The chemical structure of DOT was confirmed by FTIR and ¹H NMR. Besides, its plasticization effect on poly(vinyl chloride) (PVC) was investigated in detail, and dioctyl 2,5-furandicarboxylate (DOF) as well as dioctyl isophthalate (DOIP) with similar chemical structures were used as references. The DMA results showed that the glass transition temperature (T_g) of PVC/DOT, PVC/DOF, and PVC/DOIP was 45.1°C, 33.6°C, and 51.3°C, respectively, indicating that the plasticizing efficiency of DOT was better than that of DOIP but lower than that of DOF. However, the tensile test results exhibited that the elongation at the break of PVC/DOT was higher than that of PVC/DOF, which was attributed to the easy phase separation between DOF and PVC. In addition, DOT displayed the best volatility resistance and exudation resistance among the three plasticizers, attributed to its highest molecular weight. Moreover, the migration loss of DOT in non-polar solvents was much smaller than that of DOIP because of its stronger molecular polarity. In conclusion, DOT has good potential to replace traditional petroleum-based plasticizers and be used as a primary plasticizer for PVC.     

Intercalated hydrotalcite‐like materials and their application as thermal stabilizers in poly(vinyl chloride)

The preparation of hydrotalcites with traditional materials is often based on the corresponding salts and alkali solutions. In this study, to facilitate industrial synthesis and take advantage of the lower cost during the process, a Ca–Al–HPO₃–layered double hydroxide (LDH) was directly synthesized with calcium hydroxide, aluminum hydroxide, and sodium phosphite powders. X‐ray diffraction, Fourier transform infrared, and scanning electron microscopy analyses confirmed the successful synthesis of the phosphite‐intercalated hydrotalcite. Compared with Ca–Al–CO₃–LDH, Ca–Al–HPO₃–LDH enhanced the heat stability of poly(vinyl chloride) (PVC) in terms of both short‐term and long‐term stability because phosphite replaced the allyl chloride and reacted with the conjugated double bonds in PVC; this was deduced through a thermal aging test. The composites of Ca–Al–HPO₃–LDH, zinc stearate, and calcium stearate had a synergetic effect when added to PVC and exhibited excellent thermal stability. In addition, the phosphite reacted with ZnCl₂ in case of the phenomenon of zinc burning. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44896.     

Succinate-based plasticizers: Effect of plasticizer structure on the mechanical and thermal performance of poly(vinyl chloride) plastic formulations

A new family of succinate-based plasticizers, consisting of molecules with a linear alkyl chain capped with n-alkyl succinates on both ends, was evaluated as potential bio-based plasticizers for stiff polymers. The influence of the central and side alkyl chain lengths on the mechanical and thermal properties as well as the migration behavior of poly(vinyl chloride) (PVC)/plasticizer blends was evaluated. The central chain length had the greatest influence on plasticizer performance, with shorter chains leading to blends with higher stress at break and surface hardness, whereas long chains produced softer blends. An optimum chain central length of five carbon atoms was observed, with longer chains leading to reduced compatibility and exudation of the plasticizer at higher plasticizer concentrations. The entire family of plasticizers performed comparably or better than the commercial plasticizer di(2-ethylhexyl) phthalate (DEHP) when incorporated into the blend at concentrations of 20–60 parts per hundred resin (phr). Overall, the succinate-based plasticizers/PVC blends all exhibited equal or improved tensile properties (by up to 77%), surface hardness (reduced by up to 43%), glass transition temperature (reduced by up to 11°C), and migration into organic media (reduced by up to 38%) when compared with blends with DEHP at 40 phr.     

Bis(2‐ethylhexyl) succinate in mixtures with epoxidized soybean oil as bio‐based plasticizers for poly(vinylchloride)

Mixtures of bis(2‐ethylhexyl) succinate and epoxidized soybean oil (ESO) have been evaluated as bio‐based plasticizers for poly(vinylchloride). The rate of absorption of the bioplasticizers and their mixtures in the polymer was fast and, unlike that of petroleum‐derived plasticizers, did not vary significantly with molecular weight. These bio‐derived plasticizers and their mixtures were compatible with the polymer even at high loadings. The succinate was the most volatile and efficient plasticizer, but on heat aging of the polymer compositions, it also had the greatest deleterious effects. Diffusion coefficients and apparent activation energies of formulations containing bioplasticizer mixtures were controlled by the more volatile succinate. Mixtures comprising up to 50 wt% of the succinate yielded acceptably high‐tensile properties after thermal aging as well as better plasticization efficiency than the epoxy bioplasticizer. Although the succinate resulted in inferior volume resistivity of the polymer compositions, improvements were obtained with increasing proportions of the epoxidized derivative in plasticizer mixtures. Melt state viscosity‐shear rate curves of compositions containing dioctyl succinate (DOS) were similar to those made with two of the petroleum‐derived plasticizers, but a DOS/ESO mixture yielded extended non‐Newtonian behavior at low‐shear rates. POLYM. ENG. SCI., 55:634–640, 2015. © 2014 Society of Plastics Engineers     

Synthesis and evaluation of some fatty esters as plasticizers and fungicides for poly(vinyl acetate) emulsion

n-Fatty alcohols (average molecular weight 187), prepared from n-paraffins, were treated with a series of dibasic acids such as malonic, succinic, glutaric, adipic and phthalic anhydride to give the corresponding fatty esters. The prepared fatty esters were formulated with poly(vinyl acetate) emulsion and used as films or textile coatings. Tests such as rate of drying, mechanical properties and resistance to micro-organisms were carried out. Samples of poly(vinyl acetate) plasticized with dibutyl phthalate were also prepared and evaluated for the purpose of comparison. The antifungal activity of these compounds was studied. The results obtained indicate that the prepared fatty esters can be used not only as plasticizers but also as fungicides and in some respects they are better than the conventional dibutyl phthalate plasticizer.     

Synthesis and application of a natural plasticizer based on cardanol for poly(vinyl chloride)

A natural plasticizer with multifunctional groups, similar in structure to phthalates, cardanol derivatives glycidyl ether (CGE) was synthesized from cardanol by a two‐step modification process and characterized by FT‐IR, ¹HNMR, and ¹³CNMR. The resulting product was incorporated to PVC (CGE/PVC), and plasticizing effect was compared with PVC incorporated with two kinds of commercial phthalate ester plasticizers bis (2‐ethylhexyl) benzene‐1,4‐dicarboxylate (DOTP) and diisononyl phthalate (DINP). Dynamic mechanical analysis and mechanical properties testing of the plasticized PVC samples were performed in order to evaluate their flexibility, compatibility, and plasticizing efficiency. SEM was employed to produce fractured surface morphology. Thermogravimetric analysis and discoloration tests were used to characterize the thermal stabilities. Dynamic stability analysis was used to test the processability of formulations. Compared with DOTP and DINP plasticized samples, CGE/PVC has a maximum decrease of 9.27% in glass transition temperature (T_g), a maximum increase of 17.6% in the elongation at break, and a maximum increase of 31.59°C and 25.31 min in 50% weight loss (T50) and dynamic stability time, respectively. The obtained CGE also has slightly lower volatility resistance and higher exudation resistance than that of DOTP and DINP. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42465.