Poly Vinyl Chloride Formulations Research Articles

Migration of plasticizers from flexible PVC: Monitoring the concentration profiles by confocal Raman microspectroscopy

This study introduces and validates an effective approach for monitoring the plasticizer amount and its concentration profile in polyvinyl chloride (PVC) formulations. The method combines gravimetric measurements with confocal Raman depth profiling analysis. Several flexible PVC (pPVC) formulations were compared in this study, including: pPVC@DEHP, using the monomeric plasticizer di(2-ethylhexyl) phthalate (DEHP); pPVC@PBA, using the polymeric plasticizer poly(butylene adipate) (PBA); and crosslinked pPVC (cPVC@DEHP), where isophorone diamine (IPDA) served as the crosslinker. Migration tests were performed according to UNI EN ISO 177 standard. Spectroscopic findings were correlated with gravimetric data, highlighting strong differences in the migration behavior among the formulations. The results demonstrate the effectiveness of the proposed method in quantifying plasticizer leaching and obtaining detailed concentration profiles at fine scale.

Investigation of Cinnamic Acid Derivatives as Alternative Plasticizers for Improved Ductility of Polyvinyl Chloride Films.

This study investigates the viability of cinnamic acid derivatives as alternative plasticizers for polyvinyl chloride (PVC) films by addressing concerns about conventional phthalate-based options that pose health and environmental risks. By theoretical modeling, this research evaluates the compatibility between various cinnamic acid-based plasticizers and the PVC matrix, which suggests their potential effectiveness. Additionally, the incorporation of these plasticizers notably enhances the tensile properties of PVC films, particularly in terms of ductility and elongation at break by surpassing the neat PVC. Moreover, cinnamic acid-based plasticizers induce a drop in the glass transition temperature and storage modulus by, thereby, enhancing flexibility and reducing brittleness in the material. Although a slight reduction in the onset degradation temperature is observed, it does not impede the industrial processing of PVC plastisols at temperatures up to 190 °C. Optically, plasticized films exhibit high transparency with minimal UV and visible light absorption, which renders them suitable for applications necessitating clarity. The water vapor transmission rate analysis indicates increased permeability, influenced by molecular volumes. Atomic force microscopy reveals a compacted, homogeneous surface structure in most plasticized films, which signifies improved film quality. Thus, utilizing cinnamic acid derivatives as PVC plasticizers offers substantial mechanical and structural benefits, while compatibility ensures effective integration by contributing to environmentally sustainable PVC formulations with enhanced performance.

Investigation of thermal and mechanical properties of new nitrogen-rich organic based heat stabilizers for poly (vinyl chloride)

Urea cyanurate, as a new nitrogen-rich organic-based heat stabilizer, for the enhancement to thermal properties of polyvinyl chloride (PVC) is prepared via the simple precipitation method, in this study. Characterization, thermal and mechanical properties of the stabilized PVC were examined by means of fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA/DTG), X-ray photoelectron spectroscopy (XPS) measurements, discoloration test, congo red test and the weight-loss method, thermal aging test, and tensile analysis. Results showed that the thermal stability of PVC is improved after the addition of urea cyanurate in PVC formulation and weight loss related to HCl releasing in the normal PVC processing temperature (180°C) is less than 1%. Enhancement of the thermal properties and stability time of the PVC lead to decreased degradation tendency. Oven-aging test result showed that the color change during degradation process of PVC samples improved by adding the urea cyanurate. The tensile strength of stabilized samples were about 42%, higher as compared to the pure PVC. The optimum and best results for improving the thermal and mechanical properties of PVC were obtained by incorporating the 3 wt % of the urea cyanurate.

In‐depth rheological study of acrylic processing aids in rigid polyvinyl chloride applications

AbstractAcrylic processing aids are used widely in rigid polyvinyl chloride (PVC) applications. Key functions of processing aids in terms of processing and performance are discussed in the paper. Effect of molecular weight of acrylic processing aids on their functions are studied. Additionally, effect of processing conditions, such as temperature and shear on fusion characteristics of PVC formulations are investigated. Shear rate in the processing was varied by means of rotor speed in torque rheometer. Processing aids of comprehensive molecular weight range are evaluated in the study. It was observed that relatively lower molecular weight processing aids have different response to change in shear and temperature than higher molecular weight processing aids. Depending upon fusion conditions PVC formulations can yield either a single or double fusion peak. Generally, it was considered that ultra‐high molecular weight processing aids yield a double fusion peak, however, it was demonstrated in the studies that it is not true. Fusion conditions, temperature, and shear are the main driving forces of fusion dynamics, resulting in either a single or double fusion peak. Relatively low molecular weight acrylic processing aids can also yield double fusion peak. Melt viscosity and shear thinning properties are also examined. Relatively lower molecular weight processing aids showed higher shear thinning behavior. Effect of temperature and shear on degree of fusion was studied. It was shown that optimum processing parameters can increase the degree of fusion by ~10%.

Features of PVC/ABS compositions filling

The work is devoted to the filling of PVC (polyvinyl chloride) compositions modified with ABS (acrylonitrile-butadiene styrene) in a wide concentration range, intended for the production of profiles and moldings of various functional purposes, with short-fiber basalt fiber. Powdered samples were made by extrusion (in the form of flat profiles) and by thermoplasticizing on rolls (in the form of films). Introduction of 10-40 phr ABS in PVC formulation makes it easier to recycle the composition. Similar situation is observed when these compositions are filled with basalt fiber, which leads to insignificant decrease of MFR (melt flow index) and thermal stability, which in general does not reflect negatively on melt flow conditions, at the same time extrudate swelling index decreases by 10-15%, which indicates possibility to provide products with more precise geometric dimensions. The change in the supramolecular structure was evaluated by thermomechanical tests and by energy dispersive analysis using electron microscopy data. Thermomechanical analysis showed that the presence of large doses of ABS has a positive effect on the technological properties, leading to an earlier development of highly elastic deformations and a decrease in the yield point of the compositions. Basalt fiber contributes to an insignificant decrease in the value of high elastic deformations and an increase in the density index of meshing knots. Energy dispersion analysis has shown that introduction of basalt fiber leads to formation of homogeneous structure of PVC at lower concentrations of ABS in the composition, influencing on increase of melt flowability and thermal stability. Improved technological properties of PVC compositions filled with short-fiber basalt fiber, modified with different concentrations of ABS, allow to recommend them for production of a wide range of profile and molded products.

Thermo-mechanical, antimicrobial and biocompatible properties of PVC blends based on imidazolium ionic liquids

The aim of this study was the development of antimicrobial polyvinylchloride (PVC) blends loaded with 0.1–10% (w/w) of the ILs 1-hexadecyl-3-methylimidazolium 1,3-dimethyl 5-sulfoisophthalate (HdmimDMSIP) and 1-octyloximethyl-3-methylimidazolium hexafluorophosphate (OOMmimPF6). The synthetized ILs were characterized by 1HNMR, MALDI-TOF, DSC and TGA. PVC/ILs films were obtained by solvent casting.Thermal and mechanical properties (tensile stress TS and elongation at break EB), morphology by SEM, surface wettability, antimicrobial activity, cytotoxicity and ILs release in sterile water from PVC/ILs film blends were determined. Results demonstrated that the presence of both ILs in PVC formulation slightly affected thermal and mechanical properties of blends. The loading of both ILs into PVC matrix made PVC/ILs films hydrophilic, especially at the highest concentration of HdmimDMSIP. The PVC/ILs blends displayed antibacterial activity up to ILs lowest concentrations (0.1–0.5%). The inhibition of Escherichia coli growth was lower than that showed toward Staphylococcus epidermidis. The addition of 10% ILs concentration resulted excessive as demonstrated by accumulation of ILs on film surfaces (SEM) and ILs high release from PVC/ILs blends during the first day of water immersion. Biocompatibility studies highlighted that the addition of low amounts of both ILs into PVC matrix is not cytotoxic for mouse fibroblast cells (L929), supporting their potential use for biomedical porposes.

Assessment of derived sunflower oil as environmentally friendly plasticizers in Poly Vinyl Chloride

Epoxidized sunflower oil (ESO) and epoxidized sunflower oil methyl ester (ESOME) were synthetized and employed as secondary bio based plasticizers and combined with primary natural plasticizers. As such, di-esters isosorbide (DEI) and acetyl tributyl citrate (ATBC) used in Poly Vinyl Chloride (PVC) as compared to di-(2-ethylhexyl) phthalate (DEHP). PVC Sheets were obtained by processed the polymer and its additives on two-roll mill. The effect of the plasticizers combination on flexible sheets properties, including stabilization, migration, fusion rheological properties and light transmission have been discussed, Results have shown that ESO and ESOME have improved PVC formulations thermal stability, the weight loss by volatility has decreased in the formulations which contained ESO or ESOME. Mixtures of plasticizers have lower migration rates. Plastograph test has indicated a better compatibility of PVC with these plasticizer mixtures. The light transmission rate through PVC sheets plasticized by bio-based plasticizers mixtures is more than those containing DEHP.

Designing anti-migration furan-based plasticizers and their plasticization properties in poly (vinyl chloride) blends

The use of bio-based plasticizers with low toxicity and good compatibility with polyvinyl chloride (PVC) has attracted more attention in the recent years. With bio-based 2, 5-furandicarboxylic acid (FDCA) and butyl oligo-glycol ethers as raw materials, three liquid furan-based plasticizers of di(butyl glycol) furan-2,5-dicarboxylate, di(butyldiglycol) furan-2,5-dicarboxylate and di(butyltriglycol) furan-2,5-dicarboxylate were synthesized by direct esterification. The chemical structure of three plasticizers was characterized with FTIR, 1H NMR and 13C NMR. From DMA measurement, the glass transition temperature (Tg) of the plasticized PVC was decreased gradually when furan-based plasticizers were added to PVC formulation from 30 up to 50 phr. Due to lots of ether bonds in furan-based plasticizers, they expressed over two-fold lower migration in organic solvent compared with the traditional plasticizer diethylhexyl phthalate (DEHP). Through the characterization of elongation at break, hardness and thermal stability, furan-based plasticizers presented the same plasticization properties as DEHP, and had potential industrial application prospects.

A simple approach with scale-up potential towards intrinsically flame-retardant bio-based co-plasticizer for PVC artificial materials

As an imitation of genuine leather, polyvinyl chloride (PVC) artificial materials are versatile, but suffers from being flammable due to the presence of large amounts of combustible plasticizers. Under such circumstance, intrinsically flame-retardant plasticizers displaying dual functions have been a subject of intensive research interest. However, previous strategies attempting to covalently attach flame-retardant moiety to plasticizers invariably required either expensive starting materials or laborious and tedious procedures, ultimately limiting their scale-up application in industry. In addition, driven by escalating demand of halogen-free flame retardants worldwide from an environmental health perspective, previously reported intrinsically flame-retardant plasticizers were mainly halogen-free, less attractive in PVC artificial material industry simply because PVC itself is a halogen-containing polymer. Here, we report an approach to introduce chlorine moieties into unsaturated fatty acid methyl ester by a simple addition reaction occurring on carbon-carbon double bonds, yielding a chlorine-containing, intrinsically flame-retardant bio-plasticizer. When combined with di-(2-ethylhexyl) phthalate (DOP) in PVC formulations, the chlorinated fatty acid methyl ester is qualified as a co-plasticizer while conferring flame retardancy upon the PVC coatings. This approach involves only a one-step procedure that employs renewable fatty acid methyl esters and cheap chlorine gas as raw materials, thus being of great potential to enable intrinsically flame-retardant bio-plasticizers on a large scale to manufacture functional PVC artificial materials for application in fire-prone scenarios.Graphical abstract

Characterization of processing, rheological and dynamic mechanical thermal properties of PVC stabilized with polyphenol-based thermal stabilizer

The effects of natural polyphenol-based thermal stabilizer synthesized from tannin, a flavonoid-type natural polyphenol, on the processing, rheological and viscoelastic behaviors of polyvinyl chloride (PVC) were investigated in this work. Rheological properties of PVC were studied via three different types of rheometry techniques: torque by an instrumented batch mixer, dynamic oscillating shear rheometry, and dynamic mechanical thermal analysis (DMTA). In the course of the investigation, rotational melt rheological properties in terms of shear complex viscosity, storage modulus, and loss modulus were studied in order to evaluate the performance of tannin–cadmium complex as bio-based PVC additive and as a thermal stabilizer. Experimental results of this study for all PVC formulations with this derivative at loading percentages of 1, 2, and 3 parts per hundred of PVC resin (phr) reveal that the processing and dynamic thermal stability of PVC monitored by torque curves and rheological tests can be enhanced with the addition of this derivative. Rheological behavior of PVC stabilized with tannin derivative is superior or very close to that of PVC stabilized with trade-grade thermal stabilizer. Additionally, DMTA was carried out to see the effect of tannin–cadmium at 2 phr on the thermo-mechanical properties of PVC. All DMTA-related terms such as storage modulus and damping factor and glass transition region point out that the PVC has good viscoelastic properties compared to that of PVC stabilized with commercial thermal stabilizer.

Triacetin as a Secondary PVC Plasticizer

The use of biobased plasticizers with low toxicity and good compatibility with polyvinyl chloride (PVC) has become more attractive in the recent years in contrast with phthalate derivatives. In this study, a glycerol derivative plasticizer (triacetin—TAG) was tested as a secondary plasticizer for PVC. TAG was added to PVC formulations from 10 up to 20 phr. The increase of the plasticizer content had a great influence on the properties of PVC samples. The good miscibility and therefore the efficient plasticization action of the TAG were supported by DMA results, since narrow peaks of tan (δ) curves and reduction of the Tg values for the samples were observed. The ensuing PVC demonstrated good rheological properties and thermal stability up to 200 °C. Finally, the presence of TAG reduces the hardness of materials and does not increase their density.

The effects on the endocrine system under hepatotoxicity induction by phenobarbital and di(2-ethylhexyl)phthalate in intact juvenile male rats

Phenobarbital (PB) and Di (2-ethylhexyl) phthalate (DEHP), an anti-epileptic drug and a plasticizer used in flexible polyvinylchloride formulations, respectively, are well-known typical hepatotoxicants. This study investigated the effects of PB (100 mg/kg/day) or DEHP (500 mg/kg/day) on the endocrine system in intact juvenile/peripubertal male rats exposed for 31 days beginning on postnatal day 23. Slight hormone level changes, histopathological changes in thyroid gland or induction of UDP-glucuronosyltransferase in liver were observed in both the PB and DEHP groups. One of the assumed mechanisms inducing thyroid effects is predictable to be secondary changes based on the enhancement in thyroid hormone metabolism via the induction of hepatic microsomal enzymes. No reproductive system-related changes in organ weights, histopathology, and sexual maturation were observed in both groups. Lower testosterone level was observed in the PB group. CYP2B and CYP3A, which are involved in testosterone metabolism, were induced in liver of the PB group. There was no change of 17β-hydroxysteroid dehydrogenase activity in testis of both groups. Lower testosterone level in the PB-treated male rats was attributed to an indirect, hepatotoxicity-associated effect on the reproductive system and not to direct effects on testis such as the antiandrogenic activity and the inhibition of steroidogenesis. These results did not indicate that PB or DEHP exposure affects the endocrine system directly.

The effects of natural polyphenols and calcium-based thermal stabilizer on the rheological and thermal resistance behaviors of PVC

With the aim to understand the effect of bio-polyphenols and calcium-based thermal stabilizer on the rheological and thermal degradation properties of polyvinyl chloride (PVC), this paper practically investigates the rheological and thermal degradation behaviors of PVC using melt rheology method. Thermal degradation study was carried out by monitoring the complex viscosity of PVC using a parallel-plate rheometer run by time sweep mode at 215 °C. The presence of calcium into tannin structure after modification allows the later to have HCl scavenger ability which is considered as an essential property of most PVC thermal stabilizers. The thermal stability monitoring by time sweep rheology measurements was further corroborated by dynamic rheological data, indicating that the increase in loading value of tannin–calcium into PVC from 1 to 3 part per hundred of PVC resin resulted in a notable enhancement of the PVC storage modulus and complex viscosity due to the increased thermal stability, stable chemical structure and a higher level of polymeric chain entanglements. The rheological parameters obtained by frequency sweep at 165 °C in terms of storage and loss moduli and damping factor proved simultaneously that the PVC formulations with tannin–calcium exhibit an obvious improvement in the rheological properties which were comparable to that of PVC stabilized with Reapak B-NT/7060, an industrial-type thermal stabilizer. The results obtained indicated a promising correlation between the thermal stabilization performance of tannin–calcium as a new and fully bio-based thermal stabilizer and the rheological properties of PVC.

Plasticizers derived from cardanol: synthesis and plasticization properties for polyvinyl chloride(PVC)

Two natural plasticizers derived from cardanol (CD), cardanol acetate (CA) and epoxidized cardanol acetate (ECA), were synthesized and characterized by 1H NMR and 13C NMR. The plasticizing effects of the obtained plasticizers on semi-rigid polyvinylchloride (PVC) formulations were also investigated. Two commercial phthalate ester plasticizers, dioctyl terephthalate (DOTP) and diisononyl phthalate (DINP), were used as controls. Mechanical and thermal properties, compatibility, thermal stability, microstructure, and workability were assessed by dynamic mechanical analysis (DMA), mechanical analysis, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and dynamic stability analysis, respectively. Results indicated that the natural plasticizer ECA had overallsuperior flexibility, compatibility, thermal stability, and workability comparable to both controls. The obtained CA and ECA have lower volatility resistance and similar extraction and exudation resistance than that of DOTP and DINP. The CA was further blended with DOTP in soft PVC films. Results of DMA, TGA and mechanicalanalysis indicated that CA can serve as a secondary plasticizer to improve the related properties of soft PVC formulations. These CD derived plasticizers show promise as an alternative to fully or partially replace petroleum-based plasticizers.

Bio-based additives as renewable alternatives for polyvinylchloride formulations and application in paper coatings

Citric acid derivatives have been synthesised and incorporated into PVC formulations as sustainable alternatives, offering improved properties in paper coating applications.

Influence of Fillers on Polyvinyl Chloride Materials Thermal Resistance

Innovative materials and structures are analyzed in this paper. Multicomponent formulation of polyvinyl chloride materials containing various functional additives requires assessment of their influence on polymer stability while processing and operating. According to the nature, particulate fillers widely used in plasticized and liquid compositions based on polyvinyl chloride may have different impact on thermal resistance of materials. This paper presents the study of organic and nonorganic dispersed waist as filler in polyvinyl chloride formulation and determines key parameters of their influence on thermal resistance of composition. Polyvinyl chloride stabilization course by means of polyfunctional fillers-modifiers in different mechanisms, such as: chemical stabilization – chloride hydride acceptance, replacement of chlorine labile atom in polymer macromolecule, adjoining conjugated defective ethylenic bonds, recombination macroradicals and physical stabilization – chloride hydride sorbing, reduction of mechanical destruction by oiling, etc. have been considered. Contribution into stabilization course in various mechanisms depending on chemical nature, dispersion rate and mineral content of fillers is evaluated.

DIPHENOXYETHYLPHTALATES AND BUTOXYETHYLPHENOXYETHYLPHTALATES NEW PVC PLASTICIZER

To date, polyvinylchloride (PVC) is one of the most widely used large-scale polymers produced both in Russia and abroad. But the number of different types of products manufactured on its basis, undoubtedly, occupies a leading position. The most extensive application of PVC materials is construction. However, throughout the life of building materials and products made of polyvinylchloride (PVC) are exposed to aggressive environments of different origin (atmosphere, soil, acid, alkali, salts and their solutions, mineral and organic substances and etc.). Thus there is a significant change in their mechanical properties. Therefore, further development of PVC production and the constant expansion of the range of its application, primarily determined by the development of new chemical additives - plasticizers that meet the demands of modern exploitation. In this regard, relevant and practically significant is the question of creation of competitive formulations of PVC compounds for construction purposes that meet modern technological and operational requirements and with specific properties. This paper presents the obtaining methods and physico-chemical and mechanical properties of new plasticizers – diphenoxyethylphtalates and butoxyethylphenoxyethylphtalates based on ethoxylated alcohols (phenol and butanol) used for obtaining special materials for construction application. The optimal conditions of obtaining them through a two-stage esterification of phthalic anhydride in a single reaction volume ethoxylated alcohols. It was found that PVC formulations adding developed plasticizers by all indicators meet the requirements of the applicable standards and by such indicators as stress at elongation, breaking stress, petrol, oil and heat resistance, even superior to standard samples. Developed phthalates on the basis of ethoxylated alcohols were promising plasticizers of polyvinylchloride.

Properties of dichlorocyclopropane derivatives of syndiotactic 1,2-polybutadiene

Properties of new halogenated polymeric products containing dichlorocyclopropane groups in the macromolecules and obtained by modification of syndiotactic 1,2-polybutadiene were studied. The influence of the degree of the polymer functionalization on the rheological and physicochemical properties and on the heat resistance of the dichlorocyclopropane derivatives of syndiotactic 1,2-polybutadiene was revealed. Dichlorocyclopropanated 1,2-polybutadiene can be used as a component of plasticized polyvinyl chloride formulations, improving the processability of the polymeric compound.

Efficient Thermal Stabilization of Polyvinyl Chloride with Tannin-Ca Complex as Bio-Based Thermal Stabilizer

The potential use of tannin-Ca complex derived from tannins as bio-based thermal stabilizer and antioxidant additive for polyvinyl chloride (PVC) was investigated in this work. For this project, Reapak B-NT/7060 was applied as reference thermal stabilizer. Variable compositions: (1, 2, and 3) part per hundred ratio (phr) of tannin-Ca complex in the presence of 10 phr Dioctyl phthalate (DOP) as plasticizer in all PVC formulations were prepared by melt mixing by internal mixer at 165°C. Tannin-Ca complex was characterized by FT-IR spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX) analysis as well as by means of differential scanning calorimetry (DSC). The tannin derivative stabilization efficiency under inert atmosphere was determined by using thermogravimetric analysis (TGA). In addition, its thermal stabilization effect has been assessed in air as oxidizing atmosphere by DSC in dynamic conditions. According to TGA thermograms, the initial degradation temperature (Ti) and optimum degradation temperature (Top ) for the main degradation stage of PVC stabilized with this derivative were about 280°C and 310°C, respectively. While these were about 255°C and 293°C, respectively for PVC stabilized with commercial thermal stabilizer. Global results of TGA, DSC, SEM and EDX show that the tannin-Ca complex provides the best properties and results in stabilizing both against thermal degradation and thermal oxidation degradation of PVC.

Study of Performance Characteristics of Fabrics Coated with PVC based Formulations

The cotton base fabric with plain weave was coated with different coating formulations for exploring the best possible formulation for achieving reasonably good waterproofing and breathability. The coated fabrics were manufactured with Polyvinyl Chloride (PVC) resin, mixture of PVC and Polyurethane (PU) and PVC mixed with Polyethylene Glycol (PEG)/Ethylene Glycol (EG) additives. The properties of coated fabric were studied for two solutions of coagulation bath. The characteristics of coating film were studied by subjecting the coated fabric samples to water treatment. The film porosity was found to be high for all cases, corresponding to low rate of coagulation. Also it was observed that on washing the porosity of film was increased. The fabric coated with mixture of PVC and PU formulation found to give best breathability (around 60 to 75% of control fabric) with water penetration resistance exceeding 150 cm head of water.