Soft Polyvinyl Chloride Research Articles

Use of Guanidine-Containing Organomineral Complexes for Protection of Soft Polyvinyl Chloride Compounds from Photo- and Biodegradation

Use of Guanidine-Containing Organomineral Complexes for Protection of Soft Polyvinyl Chloride Compounds from Photo- and Biodegradation

Halloysite nanotubes immobilized by copper itaconic acid complexes as smoke suppressant for soft polyvinyl chloride

AbstractCurrently, there are few reports of core–shell‐structured smoke suppressants that can provide a growth substrate and stabilize the char layer. In response to this problem, core–shell nanoparticles of halloysite nanotubes (HNTs) coated with copper itaconate complex were prepared by layer‐by‐layer assembly method. The electrostatic forces between HNTs and copper ions and the coordination between the itaconic acid and copper ions contributed this synthesis. The micromorphology, chemical composition, and structure of HNT@CuC5H4O4 were characterized, and its effects on the flame‐retardant and smoke‐inhibition properties, mechanical properties, and thermal stability of the soft polyvinyl chloride (PVC) were investigated. The results showed that the core–shell structure of HNT@CuC5H4O4 contributed to its homogeneous dispersion in PVC and the formation of interlocking mesh structure. Thus, the incorporation of HNT@CuC5H4O4 enhanced the strength and stiffness of soft PVC without sacrificing its ductility. Besides, copper ions on HNT@CuC5H4O4 could promote the cross‐linking carbonization of the PVC at high temperature. The formed char layer catalyzed by CuC5H4O4, together with its attached three‐dimensional network structure of HNT constituted a compact and continuous char layer with high thermal stability, which effectively prevented the release of combustible volatiles and toxic gases as well as heat transfer.

Rheological and electrical percolation of reinforced soft polyvinyl chloride composites with different morphological carbon fillers

The study analyzed the electrical properties, mechanical performance, and rheological behavior of three kinds of high plasticizer-content polyvinyl chloride (PVC) composites, herein referred as SCBC, EGC and MCNTC, respectively filled with porous superconductive carbon black (SCB), flake-like expanded graphite (EG), and tubular multi-walled carbon nanotubes (MCNT). The impact of the conductive fillers' morphology on the electrical percolation and viscoelastic percolation performance of the composites were investigated to understand the conductive mechanisms. It revealed that the incorporation of SCB and MCNT can induce both viscoelastic and electrical percolation in the composites. The thresholds for viscoelastic percolation for SCBC and MCNTC are between 2.35-3.11 vol% and 2.72–3.59 vol%, respectively, which are lower than their electrical percolation thresholds of 3.85 vol% for SCBC and 3.65 vol% for MCNTC. The nature of PVC chains, which can transmit force but not electrons, results in a higher electrical percolation threshold than the rheological percolation threshold. Despite MCNT's poorer dispersion, its high aspect ratio and one-dimensional tubular shape enabled it to achieve electrical percolation at a lower loading level. Due to the poor dispersion, EG did not cause either viscoelastic or electrical percolation in the composites within the 0–9 vol% range.

Plasticizers Used in Polyvinyl Chloride Toys (2019-2020)

We determined the fifteen types of plasticizers, including four kinds of phthalic acid esters (PAEs) used in 220 polyvinyl chloride (PVC) toys on Japanese market from 2019 to 2020. Three kinds of previously undetected types of PAEs were also detected, but not identified in this study. Di (2-ethylhexyl) terephthalate (DEHTP) was the highest detection rate in 209 soft PVC toys out of 220 toys, with 71.2% for designated toys and 88.9% for not-designated toys, respectively, showing a gradual increase from the previous reports in 2009 and 2014. On the other hand, the usages of o-acetyl tributyl citrate and adipic acid esters decreased, but the six types of PAEs prohibited to use for the designated toys in Japan were not detected in them, the usage of diisobutyl phthalate were increased. In contrast, four types of PAEs were detected in not-designated toys. Among them, the detection ratio of di (2-ethyhexyl) phthalate decreased to about 1/10. The content levels of plasticizers in per each sample were continued to keep low level from the report five years ago. These results showed that the main plasticizer used in PVC toys is DEHTP, and that the usage of other plasticizers was decreased.

Multiphysics Modeling Framework for Soft PVC Gel Sensors with Experimental Comparisons

Polyvinyl chloride (PVC) gels have recently been found to exhibit mechanoelectrical transduction or sensing capabilities under compressive loading applications. This phenomenon is not wholly understood but has been characterized as an adsorption-like phenomena under varying amounts and types of plasticizers. A different polymer lattice structure has also been tested, thermoplastic polyurethane, which showed similar sensing characteristics. This study examines mechanical and electrical properties of these gel sensors and proposes a mathematical framework of the underlying mechanisms of mechanoelectrical transduction. COMSOL Multiphysics is used to show solid mechanics characteristics, electrostatic properties, and transport of interstitial plasticizer under compressive loading applications. The solid mechanics takes a continuum mechanics approach and includes a highly compressive Storakers material model for compressive loading applications. The electrostatics and transport properties include charge conservation and a Langmuir adsorption migration model with variable diffusion properties based on plasticizer properties. Results show both plasticizer concentration gradient as well as expected voltage response under varying amounts and types of plasticizers. Experimental work is also completed to show agreeance with the modeling results.

Thermogravimetric analysis for the characterization and comparative analysis of polyvinyl chloride (PVC) wall panel

In this paper, thermogravimetric analysis of different types/grades of polyvinyl chloride (PVC) wall panel is carried out using thermogravimetric analyzer. The data output from the analyzer is subjected to data analysis software i.e., OriginPro 2018, from which thermal attributes are find out for different grades of PVC wall panel i.e., soft PVC, hard PVC, WPVC and SPVC. The thermogravimetric attributes i.e., onset degradation temperature Ti, final degradation temperature Tf,, reaction interval and the peak temperature TP from the derivative thermogravimetric curve for the four basic types of PVC were comparatively analyzed for the characterization purpose. Beside the thermal characterization, the thermogravimetric analysis also disclosed the compositional attributes of the four types of PVC wall panel. The analysis in this paper characterized the SPVC as the most thermally stable PVC wall panel followed by hard, soft and WPVC.

SOFT PVC COMPOUNDING EXTRUDER DESIGN

Polyvinyl chloride (PVC) is one of the most preferred thermoplastics in the world due to its compatibility with various additives. PVC products are examined in two groups soft and rigid. Sheath, insulation, and filling materials used in electrical cables are some of the common usage areas of soft PVC. In this study, a soft PVC compound extruder machine was designed and manufactured. The system consists of 6 components: powder feeding system, main rotor, discharge transfer screw system, pelletizer, pellet cooling (cooler) unit and main control panel (HMI). In the designed and produced machine, the temperature values can be entered into the HMI panel according to the desired formulation, and the temperatures of the desired sections can be controlled during the compound production using thermocouples. Heating is brought to the desired level using PID control with resistances, cooling with fans in the main screw area and water in the transfer area. During the compound production process, many values such as temperature and pressure values can be controlled from the material feeding section to the pelletizer section. The density of the soft PVC compound produced was measured as 1.475 gr/cm3 . The test sample was produced from PVC compound, which was produced via the compounder designed and manufactured in this study, with a laboratory-type extruder. Tensile and elongation tests were carried out according to the ISO 527-2 test method. As a result of the test, it was observed that produced soft PVC compound extended by 280%. As a result of the experiments, it has been determined that the designed and manufactured compounder machine produces the sheath, insulation and filling materials (Plasticized PVC) used in the electrical cables appropriately.

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.

Design of fishtail structure based on oscillating mechanisms using PVC gel actuators

Bionic robot fish, as a kind of underwater robots, has already demonstrated great potential in the ocean. Developing soft actuators for the bionic robot fish has become a key issue. This paper proposed a novel robot fishtail consisting of oscillating mechanisms and the stacked soft polyvinyl chloride (PVC) gel actuators. Based on the fish body wave curve used to control the kinematics of fish swimming, a bionic fishtail skeleton with six joints was developed. A stacked PVC gel actuator was fabricated and its mechanical properties and frequency response characteristics were analyzed. On this basis, a fishtail prototype was fabricated, assembled and tested, which showed good agreement with the theoretical prediction. In addition, mechanical properties and frequency response characteristics of the prototype were also studied. The results showed that the swing amplitude of the fishtail could generate a peak value at about 1.5 Hz (2 Hz on land) due to the resonance effect, which was conducive to the swing of the bionic robot fish. And the underwater tests have demonstrated that the fishtail structure can still generate propulsion and move in the water. The conclusion can provide guidance for the design of bionic robot fish in practical application.

Effects of modified tributyl citrate as a novel environmentally friendly plasticizer on the mechanical property and migration stability of soft polyvinyl chloride

AbstractIn this study, a novel environmentally friendly plasticizer, 12‐14 alkyl ether tributyl citrate (AETBC), was synthesized via high‐temperature ring‐opening reaction, and its chemical structure was characterized by Fourier transform infrared (FTIR) spectroscopy and proton nuclear magnetic resonance (1H NMR) spectroscopy. AETBC was used to plasticize polyvinyl chloride (PVC), and the mechanical property and thermal degradation of the plasticized PVC was studied. The migration stability and compatibility of AETBC in PVC were also investigated and compared with three commonly used plasticizers. The results show that PVC plasticized with AETBC has better mechanical property and migration stability than that plasticized with dioctyl phthalate (DOP), tributyl citrate (TBC) and acetyl tributyl citrate (ATBC), and AETBC is more effective than TBC and ATBC in improving the thermal stability of PVC. In conclusion, AETBC can be produced by a simple way for use as a promising alternative to DOP in preparing flexible PVC films.

Developing a Phototactic Electrostatic Insect Trap Targeting Whiteflies, Leafminers, and Thrips in Greenhouses.

Simple SummarySilverleaf whiteflies (Bemisia tabaci), vegetable leafminers (Liriomyza sativae), and western flower thrips (Frankliniella occidentalis) are very serious pests of greenhouse tomatoes. In Japan, growers of organic tomatoes currently use large numbers of yellow sticky traps to control insects, but these traps need replacing very regularly, as the sticky surface becomes clogged with insects. An electric field-generating apparatus, described herein, is a potential physical tool to control these pests that have entered greenhouses. The electric field was formed in the space between oppositely electrified insulated conductors arrayed in parallel with fixed separation. Although these conductors created a sufficiently strong force to capture insects entering the field, the force was insufficient to capture insects outside the field. The positive phototaxis of these insects was an inspiration to develop an improved electrostatic insect trap, which was constructed by introducing oppositely charged yellow-colored water into paired transparent insulator tubes to produce opposite poles. The finished apparatus exhibited coloration and insect attraction characteristics similar to commercial yellow sticky traps, but had the advantage that they could be cleaned easily and remain effective for long periods. The surfaces of the insulator tubes containing the charged yellow water were electrostatically active, but not excessively sticky, thus, the apparatus could be placed close to the plants. The close location of the devices enabled preferential attraction of flying or plant-settling insects to the trap. The present study provided an experimental basis for developing an electrostatic device to attract and capture insects that enter greenhouses.Our aim was to develop an electrostatic apparatus to lure and capture silverleaf whiteflies (Bemisia tabaci), vegetable leafminers (Liriomyza sativae), and western flower thrips (Frankliniella occidentalis) that invade tomato greenhouses. A double-charged dipolar electric field producer (DD-EFP) was constructed by filling water in two identical transparent soft polyvinyl chloride tubes arrayed in parallel with fixed separation, and then, inserting the probes of grounded negative and positive voltage generators into the water of the two tubes to generate negatively and positively charged waters, respectively. These charged waters electrified the outer surfaces of the opposite tubes via dielectric polarization. An electric field formed between the oppositely charged tubes. To lure these phototactic insects, the water was colored yellow using watercolor paste, then introduced into the transparent insulator tubes to construct the yellow-colored DD-EFP. This apparatus lured insects in a manner similar to commercially available yellow sticky traps. The yellow-colored DD-EFP was easily placed as a movable upright screen along the plants, such that invading pests were preferentially attracted to the trap before reaching the plants. Furthermore, pests settling on the plants were attracted to the apparatus, which used a plant-tapping method to drive them off the plants. Our study provided an experimental basis for developing an electrostatic device to attract and capture insects that enter greenhouses.

Toxicokinetic studies of di-isobutyl phthalate focusing on the exploration of gender differences in rats

Due to the use of di-isobutyl-phthalate (DiBP) in the production of soft-polyvinyl chloride articles, it is currently a hazardous substance prevalent in human daily life. However, reports on DiBP's toxicokinetics are still very scarce. And no studies have been reported on gender differences in DiBP toxicokinetics. Therefore, this study was conducted in accordance with these research needs. DiBP of 100 mg/kg has been exposed to male and female rats single or multiple times. DiBP and its major metabolite, mono-isobutyl-phthalate (MiBP), were quantified from various biological samples obtained from rats administered with DiBP. Based on these results, several toxicokinetic parameters were estimated. Toxicokinetic results between genders were compared, and from this, existence and extent of gender differences in DiBP's toxicokinetics were explored. Investigation of presence and extent of subacute toxicity in male and female rats following multiple exposures to DiBP were also conducted. This study provided comprehensive information on DiBP toxicity and gender differences that have not been reported in detail. Results of these studies imply that subacute toxicity in liver, kidney, lung, and testis of rats at 100 mg/kg of DiBP is modest and that there is little difference in toxicokinetics between genders. And in both male and female rats, the metabolism of DiBP (to MiBP) was significant, and excretion of MiBP into urine was a major indicator of DiBP exposure.

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.

Investigation of PolyVinyl Chloride Plastisol Tissue-Mimicking Phantoms for MR- and Ultrasound-Elastography

Objective: Realistic tissue-mimicking phantoms are essential for the development, the investigation and the calibration of medical imaging techniques and protocols. Because it requires taking both mechanical and imaging properties into account, the development of robust, calibrated phantoms is a major challenge in elastography. Soft polyvinyl chloride gels in a liquid plasticizer (plastisol or PVCP) have been proposed as soft tissue-mimicking phantoms (TMP) for elasticity imaging. PVCP phantoms are relatively low-cost and can be easily stored over long time periods without any specific requirements. In this work, the preparation of a PVCP gel phantom for both MR and ultrasound-elastography is proposed and its acoustic, NMR and mechanical properties are studied.Materials and methods: The acoustic and magnetic resonance imaging properties of PVCP are measured for different mass ratios between ultrasound speckle particles and PVCP solution, and between resin and plasticizer. The linear mechanical properties of plastisol samples are then investigated over time using not only indentation tests, but also MR and ultrasound-elastography clinical protocols. These properties are compared to typical values reported for biological soft tissues and to the values found in the literature for PVCP gels.Results and conclusions: After a period of two weeks, the mechanical properties of the plastisol samples measured with indentation testing are stable for at least the following 4 weeks (end of follow-up period 43 days after gelation-fusion). Neither the mechanical nor the NMR properties of plastisol gels were found to be affected by the addition of cellulose as acoustic speckle. Mechanical properties of the proposed gels were successfully characterized by clinical, commercially-available MR Elastography and sonoelastography protocols. PVCP with a mass ratio of ultrasound speckle particles of 0.6%–0.8% and a mass ratio between resin and plasticizer between 50 and 70% appears as a good TMP candidate that can be used with both MR and ultrasound-based elastography methods.

Towards bio-based plasticizers with reduced toxicity: Synthesis and performance testing of a 3-methylphthalate

As a very durable material, soft polyvinyl chloride (PVC) is used for many applications in the field of consumer products. To enable the desired properties, for example for medical devices, the addition of plasticizers is required. For this purpose, mostly dialkyl phthalates are used being produced on a multi-million tons scale annually. Since some of these are associated with human health effects, there is an increasing demand for the search of alternatives. Besides reduced toxicity while maintaining excellent performance features, an economic access as well as biorenewable starting materials are further criteria, which should be ideally fulfilled by such a new plasticizer generation. Targeting these demands and in contrast to most available substitutes being based on petrochemical feedstock, we developed a synthetic route starting from bio-renewable platform chemicals. In detail, a Diels-Alder reaction of 2-methylfuran and maleic anhydride and subsequent dehydration leads to three phthalate derivatives with different alcohol components bearing a methyl group at the aromatic ring. As a representative substance, di(2-ethylhexyl) 3-methylphthalate was chosen for performance tests, and this new bio-based alternative offers properties similar to known plasticizers in such initial studies.

Effect of Modified Cardanol as Secondary Plasticizer on Thermal and Mechanical Properties of Soft Polyvinyl Chloride

This study represents the first attempt to prepare a novel cardanol-based plasticizer. Modified cardanol (MC, i.e., phosphorylated cardanol) containing nitrogen and phosphoric acid groups was synthesized and then incorporated into polyvinyl chloride (PVC) as the secondary plasticizer for partial substitution of dioctyl phthalate (DOP). The molecular structure of MC was characterized by Fourier transform infrared spectroscopy, 1H nuclear magnetic resonance (NMR), and 31P NMR spectroscopy. The thermal degradation behavior, mechanical performance, and compatibility of MC were also investigated. The substitution of DOP with MC enables PVC blends to have higher thermal stability, tensile strength, and leaching resistance. The tensile strength is increased from 17.7 MPa for DOP/PVC blend (MC-0) to 25.7 MPa for MC/PVC blend (MC-4), and the elongation at break is increased from 256 to 432%, respectively. The microstructure of the tensile fractured surface was studied by scanning electron microscopy. The results show that the addition of MC allows PVC blends to have well-balanced properties of flexibility and strength and excellent migration resistance.

Volatile and semivolatile organic compound emissions from polymers used in commercial products during thermal degradation.

Emissions of volatile and semivolatile organic compounds from various kinds of polymer sheets during thermal degradation process were determined by the passive flux sampling method. The polymer sheets used were commercial products made of: polyethylene (PE), ethylene-vinyl acetate (EVA), polypropylene (PP), polyacetal (POM), polycarbonate (PC)), and polymer sheet samples: poly (methyl methacrylate) (PMMA), polyethylene terephthalate (PET), polystyrene (PS) and four types of poly vinyl chloride (PVC) with different contents of additives; (bis(2-ethylhexyl)phthalate (DEHP)), and triphenylphosphine (TPP)). The emission fluxes from the polymer sheets were measured for up to 30 days stored under a constant temperature (25–75 °C). Emission of various kinds of chemicals were observed from PVC sheets including and products of polymer degradation, while emission of hydrocarbons were dominant from PE, PP and EVA, and the emission of an additive (DEP) only was observed from PMMA, PET, POM and PC. The TVOC (total VOC) emission rates from PVC sheets with DEHP and TPP (soft PVCs) were in the range of 30–120 mg m−2 h−1 at 50 °C, which were much higher than the TVOC emission rates from other polymers. The emission rates for these chemicals for the same sampling period increased dramatically as the temperature increased. The temperature-dependences of the emission rates from the soft PVC sheet for a given sampling period could be expressed using an Arrhenius-type equation, and the apparent emission activation energy EA, correlated well with the enthalpy of vaporization ΔHVAP by the following empirical equation.EA=2.27ΔHvap−115We also found that the emission rates of chemicals changed with time with different changing characters, and the activation energy decreased with the progress of the polymer degradation.

Investigation on the adhesive mechanism of mounting brackets formed by injection molding with a safety glass insert

ABSTRACT To address deficiencies in traditional coating and adhesive processes for installing auto safety glasses, mounting brackets for auto safety glass were formed by the insert injection molding process via employing an insert. Specifically, float glass was used as the insert, Chemlok CH456 and CH489 were utilized as the glass primer, and soft polyvinyl chloride (PVC) was adopted as the material for injection molding. The adhesive force of the mounting brackets was measured, and the adhesive behavior of the mounting brackets was characterized using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The results indicated that the adhesive force of the mounting brackets obtained by insert injection molding can be as high as 1027 N. The results showed that the primer located in fracture regions was torn from PVC and the glass. Double-interface adhesion was found between the glass, the primer, and PVC. In particular, the primer and the glass surface formed strong adhesion by mechanical locking, diffusion existed between PVC and the primer, and the diffusion depth was greater than 10 μm. This process greatly shortens the production cycle of the mounting brackets for auto safety glass and greatly improves the adhesive quality of the mounting brackets.

Sustainable synthesis of bio‐based hyperbranched ester and its application for preparing soft polyvinyl chloride materials

AbstractIn this study, bio‐based hyperbranched ester was synthesized from castor oil. The chemical structure of the bio‐based hyperbranched ester obtained was characterized with Fourier transform infrared and 1H NMR spectra. Soft polyvinyl chloride (PVC) materials were prepared via thermoplastic blending at 160 °C using bio‐based hyperbranched ester as plasticizer. The performances including the thermal stability, glass transition temperature (Tg), crystallinity, tensile properties, solvent extraction resistance and volatility resistance of soft PVC materials incorporating bio‐based hyperbranched ester were investigated and compared with the traditional plasticizer dioctyl phthalate (DOP). The results showed that bio‐based hyperbranched ester enhanced the thermal stability of the PVC materials. The Tg of PVC incorporating bio‐based hyperbranched ester was 23 °C, lower than that of PVC/DOP materials at 28 °C. Bio‐based hyperbranched ester showed a better plasticizing effect, solvent extraction resistance and volatility resistance than DOP. The plasticizing mechanism is also discussed. © 2018 Society of Chemical Industry

Fresnel zone plate fabricated using a polyvinyl chloride gel

Based on creep-induced deformation of a polyvinyl chloride (PVC) gel in an electric field, a Fresnel zone plate (FZP) is fabricated. The employed electrode is constructed with a series of concentric zones, and the soft PVC gel coated on the electrode forms a flat membrane. By applying a DC voltage to the electrode, electrons are injected to the PVC gel. Due to the generated electrostatic force, the surface of the PVC membrane is undulated. The configuration of the PVC membrane resembles the pattern of the electrode. As a result, the PVC membrane functions as an FZP. The results show that incident light passing through the FZP can be diffracted, producing a focused spot due to constructive interferences. The maximum diffraction efficiency can reach ∼32.5 % , and the focal length is switchable. The advantages of this FZP are the ease of manufacturability, compactness, large size, and optical isotropy.