PVC Materials Research Articles

Human metabolism and kinetics of tri-(2-ethylhexyl) trimellitate (TEHTM) after oral administration.

Tri-(2-ethylhexyl) trimellitate (TEHTM) is a plasticizer for PVC material and is used for medical devices as an alternative to di-(2-ethylhexyl) phthalate. As plasticizers are known to migrate easily into contact liquids, exposure of patients to TEHTM is highly probable. In the present study, human metabolism pathways of TEHTM and its elimination kinetics were investigated. For that purpose, four healthy volunteers were orally exposed to a single dose of TEHTM. TEHTM and its postulated primary metabolites were investigated in blood samples (up to 48h after exposure), and in urine samples (collected until 72h after exposure) using liquid chromatography tandem mass spectrometry (LC-MS/MS). TEHTM was found to be regioselectively hydrolyzed to its diesters di-2-(ethylhexyl) trimellitates (1,2-DEHTM, 2,4-DEHTM) with maximum blood concentrations at 3-h post-exposure, and to its monoester isomers mono-2-(ethylhexyl) trimellitates (1-MEHTM, 2-MEHTM) with peak blood concentrations 5-h post-exposure. For the elimination of investigated urinary metabolites, biphasic elimination kinetics was observed. The most dominant urinary biomarker was found to be 2-MEHTM (2-mono-(2-ethylhexyl) trimellitate), followed by several specific secondary metabolites. All in all, approximately 5.8% of the orally administered dose was recovered in urine over a period of 72h, indicating a comparatively low resorption rate of TEHTM in humans in combination with an apparently rather slow metabolism and excretion rate. In fact, TEHTM and selected metabolites were still detectable in blood and urine 48-h and 72-h post-exposure, respectively. This study is the first to elucidate TEHTM metabolism pathways in humans and to identify metabolites of TEHTM in blood and urine by usage of especially designed human biomonitoring methods. Powerful tools for exposure monitoring and risk assessment of TEHTM are therewith available for future research.

Gold Nanoparticle-Modified Poly(vinyl chloride) Surface with Improved Antimicrobial Properties for Medical Devices.

Despite the significant technological progress achieved in the past decades in the medical field, device-related infections carry a heavy social and economic burden. Surface modification of medical equipment is one of the most interesting approaches employed to improve the antibacterial activity of a material. Herein, we developed a process for the gold nanoparticle modification of a poly(vinyl chloride) laryngeal tube, which typically serves as an airway management device. In our study, we focused specifically on increasing the antimicrobial properties of the material while maintaining its biocompatibility. We applied two different modification methods to the poly(vinyl chloride) laryngeal tube. An increase in the antimicrobial activity of the surface was observed for both methods. In addition, the adsorption of bacterial cells on the material surface was assessed. We determined that the number of colonies cultured in the presence of the gold nanoparticle-modified samples or absorbed to the material surface decreased significantly compared with the control group. The trend was observed for both Gram-positive and Gram-negative strains. Moreover, it was established that the designed material did not exhibit a lethal impact on a control cell line. Finally, we noted discrepancies in the growth of bacteria cultured in the presence of modified or unmodified PVC material as well as differences in cell adherence to its surface. The proposed poly(vinyl chloride) modifications are most effective against Gram-positive bacteria, especially L. monocytogenes. Nevertheless, it ought to be emphasized that due to their different properties, each strain requires an individual approach.

Halogenated flame retardants in building and decoration materials in China: Implications for human exposure via inhalation and dust ingestion

In this study, polybrominated diphenyl ethers (PBDEs), novel brominated flame retardants (NBFRs), and dechlorane plus (DPs) were analyzed in seven categories of building and decoration materials. The total concentrations of analyzed FRs ranged from 1.19 ng/g (diatomite powder) to 9532 ng/g (expanded polystyrene panel). Relatively high concentrations were detected in foam samples and PVC materials, followed by sealing materials, boards, wallpaper, paints, and wall decoration powders. BDE209 was the most detected compound with the highest concentrations in almost all materials, followed by decabromodiphenyl ethane (DBDPE), which was consistent with their productions and consumptions in China. The estimated PBDE concentrations in air and dust based on material concentration and emission rate were comparable with those detected in real samples. Adult and infant exposures via inhalation and dust ingestion were assessed. The estimated exposures to BDE209 via dust ingestion were 1.36 and 0.12 ng/(kg bw d), which were 19- and 4-fold higher than those via inhalation for infants and adults, respectively. This suggested that dust ingestion was a significant pathway of human BDE209 exposure, especially for infants. For the other PBDE congeners (∑7PBDEs), the estimated exposures via inhalation were 2.60 and 1.32 ng/(kg bw d) for infants and adults, respectively. Despite the low estimated human exposures to PBDEs compared to the oral reference doses, the exposure associated with building and decoration materials still requires more attention because of the potential risks from other exposure pathways and undetected FRs in those materials.

Development, characterisation and Finite Element modelling of novel waste carpet composites for structural applications

Carpets are composite materials and, like many composite materials, waste carpet is both difficult and expensive to recycle because of the complicated, multi-stage processes involved. Consequently, in the United Kingdom, approximately 400,000 tonnes of carpet waste are sent to landfill annually. However, the landfill option is becoming uneconomic due to increasing landfill charges, the reduction in landfill sites and changes in environmental legislation. This dual economic and environmental burden has led to research interest in the processing of waste carpets into useful feedstocks for use in manufacturing. This study describes the experimental characterisation of a novel structural composite material that has been fabricated from waste carpets, and which is intended for use in low grade structural applications such as agricultural fencing. Details of the manufacturing process for the composites are described, as are the results of tensile and three-point bending tests, and the observed failure modes post-testing. In addition, Finite Element (FE) analysis was used to simulate the structural behaviour of fencing posts and rails manufactured from the carpet-based composite, and these results are compared with commercially available timber and PVC equivalent designs. Finally, structural analysis and design optimisation of the composite fencing was undertaken and this is used to demonstrate that from a mechanical property standpoint, the novel waste carpet structural composite may offer potential as an alternative to the timber and PVC materials typically used in such applications. Therefore, this study has demonstrated a practical approach for recycling carpet waste, which could lead to a substantial reduction in the volume of carpet waste discarded to landfill and subsequently yield both economic and environmental benefits.

Fabrication of PU/AC microcapsule for controlling electrical property and diisooctyl terephthalate migration from flexible PVC materials

A synthetic approach for the preparation and conductive polyurethane (PU)/activated carbon (AC) microcapsule to poly(vinyl chloride) (PVC) is described. The developed flexible PVC/PU/AC microcapsule composites are economically and ecologically viable, because it is based on AC as inexpensive starting material; the reactions can be carried out one-pot with quantitative yields of the PU/AC microcapsule. The approach is furthermore highly versatile and allows for the preparation of excellent plasticiser migration stability, electrical property and mechanical properties that may be adjusted to a broad range of applications from highly flexible to semi-rigid PVC.

ZnS Nanocrystals as an Additive for Gamma-Irradiated Poly (Vinyl Chloride)

Zinc sulfide (ZnS) was synthesized by sonochemical method and nanoparticles with crystallite size around 2 nm were obtained. PVC containing ZnS nanoparticles at concentrations of 0.10; 0.30; 0.50; 0.7 and 1.00 wt% were gamma irradiated (60Co) at room temperature in air. No appreciable decrease in PVC Viscosity-Average Molar Mass (Mv) was observed for samples containing 0.7 wt% of ZnS nanocrystals. It was demonstrated that the addition of ZnS nanocrystals imparted molecular protection to the polymer matrix while improving flexibility, by decreasing the Young Modulus of PVC films. These results suggest the use of sonochemically synthesized ZnS nanocrystals as a new additive for radiation-grade PVC materials.

A Strategy for Nonmigrating Plasticized PVC Modified with Mannich base of Waste Cooking Oil Methyl Ester

The waste cooking oil (WCO) production from the catering industry and food processing industry causes serious environmental, economic and social problems. However, WCO can be used for the preparation of fine chemicals such as internal plasticizer. With this aim, this work is focused on preparing internal plasticizer by using WCO and determining technical viability of non-migration poly (vinyl chloride) (PVC) materials. The mannich base of waste cooking oil methyl ester (WCOME) was synthesized from WCO via esterification, interesterification and mannich reaction, which was used to produce self-plasticization PVC materials as an internal plasticizer. The results showed that the PVC was plasticized effectively. Self-plasticization PVC films showed no migration in n-hexane, but 15.7% of dioctyl phthalate (DOP) leached from DOP/PVC(50/50) system into n-hexane. These findings transformed the traditional plastic processing technology and obtained cleaner production of no migration plasticizer from WCO.

Effect of Zinc Hydroxystannate Coated M-HOS Whisker on Flame Retardant Properties of Flexible PVC

Abstract Zinc hydroxystannate ( ZHS) coated magnesium salt whisker (M-HOS) was synthesized via co-precipitation method and was applied to flexible PVC materials. Zinc hydroxystannate coated M-HOS flame retardants were characterized by XRD and ESEM, the effect of ZHS coated M-HOS to the thermal and flame retardant properties of flexible PVC are analyzed by thermal analysis, limited oxygen index (LOI) and cone calorimeter test. Results showed that ZHS coating is asymmetrical, and the fire retardation and smoke suppressant properties of PVC filled with zinc hydroxystannate coated M-HOS were favorable.

THE EFFECT OF CEMENT ADDITIVES IN PVC MATERIALS

The aim of the present paper is to show the effect of cement modifier behaviors in PVC materials. The PVC and the Portland cement are important materials in the industrial area. It can reach excellent properties if mixing the two materials with each other. The cement worked as filler in PVC, as shown the mechanical tests. The oxygen index was determined, accordingly the result show higher oxygen index value. That means the blend shows higher fire resistance comparing to neat PVC. The cement worked as a structural modifier, it caused modification in the blends structure and properties. From the mechanical tests, such as impact-, tensile-, flexural- and hardness tests the blend gives similar mechanical properties to neat PVC. The research presented in this paper shows that the cement mixed with PVC shows higher stability, fire resistance and similar mechanical properties as rigid PVC.

Cardanol Groups Grafted on Poly(vinyl chloride)-Synthesis, Performance and Plasticization Mechanism.

Internally plasticized poly(vinyl chloride) (PVC) materials are investigated via grafting of propargyl ether cardanol (PEC). The chemical structure of the materials was studied by FT-IR and 1H NMR. The performace of the obtained internally plasticized PVC materials was also investigated with TGA, DSC and leaching tests. The results showed that grafting of propargyl ether cardanol (PEC) on PVC increased the free volume and distance of PVC chains, which efficiently decreased the glass transition temperature (Tg). No migration was found in the leaching tests for internally plasticized PVC films compared with plasticized PVC materials with commercial plasticizer dioctyl phthalate (DOP). The internal plasticization mechanism was also disscussed according to lubrication theory and free volume theory. This work provides a meaningful strategy for designing no-migration PVC materials by introducing cardanol groups as branched chains.

A composition of phosphaphenanthrene groups-containing castor-oil-based phosphate plasticizer for PVC: Synthesis, characterization and property

A composition of phosphaphenanthrene groups-containing castor-oil-based phosphate plasticizer (PGPP) was synthesized and characterized. Flame retardant PVC blends cooperated with different mass of PGPP were prepared. Flame retardancy of PVC blends were investigated with LOI, TGA, TGA-FTIR, TGA-MS and cone calorimeter. Flame retardant mechanism was also studied. The flame retardant performance of PGPP provides novel route for efficient use of vegetable oil and preparing advanced flame retardant PVC materials.

Experimental study of the impact noise through concrete floor with resilient layers

In this paper, we present an experimental approach to evaluate the sound transmission through floors and building structures. This method is developed in our laboratory at the National Center of Studies and Integrated Research of Building Engineering, CNERIB, Algeria. The method is based on measurement of sound due to impact vibration generated by a standard tapping machine placed on the upper surface of a small concrete floor. This floor has dimensions of 1.2(m)×0.8(m)×0.2(m) and simply supported on four elastic supports with 2 cm of rubber layer. The natural frequency of the floor is measured with an ambient vibration apparatus, and the obtained value is f = 19 Hz. The measurement consists of recording vibration levels in the upper and lower surfaces of the floor, in 1/3 octave frequency bands between 16 Hz and 16 KHz using piezoelectric accelerometer Brüel and Kjær 4508. The sound level meter Brüel and Kjær 2270 has been used to analyze the vibration signal for different cases. The weighted sound reduction index of the floor has 4 dB without any cover. Some samples of cover floor are tested using this procedure. The results show that the weighted sound reduction index of resilient layer can reach 18 dB, 11.6 dB and 6.6 dB for the rubber, Bitumen and PVC material, respectively. The important results obtained in this paper can be used as a platform to correct the impact sound insulation in multi-storey residential building and renovation plans using recycled resilient materials.

Modal Analysis of a Small Wind Turbine Blade made of Different Materials

A wind turbine is a mechanical device that uses wind energy to generate power by converting the kinetic energy of the rotor blade, Small wind turbines need to be installed with affordable cost, and it should be reliable and maintenance free small-scale wind turbines produces useful electrical energy in developing countries. And also in developed countries for autonomous applications in locations that are far away from the grid power. In the present, work the dynamic parameters of small wind turbine blade are determined by carrying modal analysis on different materials. Modal analysis of wind turbine blade made up of Aluminium PVC and composite materials is carried out to obtain Natural frequencies and corresponding mode shapes by the finite element analysis software ANASYS 14.5. Wind turbine blade is modelled by using modelling software and the model meshes with tetrahedral elements. Modal analysis of wind turbine blade is carried out by applying the fixed supports at the one end of the blade and other end left free. Five natural frequencies and five mode shapes are extracted for wind turbine blades of different materials.

Self-Plasticization of PVC via click reaction of a monooctyl phthalate derivative

Abstract Modified PVC (M-PVC) material with suppressed migration and low glass transition temperature was prepared via click reaction of a monooctyl phthalate derivative. Chemical structure and composition of M-PVC were characterized by FT-IR, 1H NMR and element analysis. Thermal stability, glass transition temperature and migration stability of M-PVC were studied with TGA, DSC and migration tests, respectively. The study showed that M-PVC exhibited poor thermal stability, and low glass transition temperature of 66.0°C. No migration was found in distilled water, 10% (v/v) ethanol, 30% (w/v)acetic acid and petroleum ether. The PVC material is expected to preparing PVC products in the areas with high migration resistance requirement.

Self-Plasticization of PVC Materials via Chemical Modification of Mannich Base of Cardanol Butyl Ether

The internally plasticized PVC materials by displacement of chlorine with mannich base of cardanol butyl ether, that is, the covalent attachment of the cardanol-based internal plasticizer to the PVC matrix, is descried for the first time. The chemical structure and properties of cardanol-based internal plasticizer and internally plasticized PVC materials was characterized. The results showed that the Tg of self-plasticization PVC material decreased from 85.6 to 49.3 °C when chlorine atoms in PVC were substituted with mannich base of cardanol butyl ether, tensile strength decreased from 30.33 to 18.86 MPa, and the elongation at break increased from 180.37% to 357.20%, which illustrated that mannich base of cardanol butyl ether played internally plasticized effect on PVC. The internal plasticization mechanism was also studied. Self-plasticization PVC films showed no migration in n-hexane, but 15.7% of DOP leached from the DOP/PVC system into n-hexane. The PVC materials were expected to be commercial applica...

ANALYSIS OF HIP BIOMECHANICS IN PATIENTS WITH HIP REPLACEMENT SURGERY

The effect of the forming materials on surface quality of the self-consolidating and highly workable concretes was experimentally evaluated. Several mixtures having wide ranges of workability and rheology were investigated. The mixtures were placed in a Z-shaped mold. No mechanical consolidation was applied at all. The sides of the mold were built up using plywood, PVC, steel, and permeable formwork liner using a polyester filter. The concrete surface quality was evaluated in terms of the voids, bleeding, segregation, and insufficient self-consolidation, using an image processing technique. The surface diameter and area of the voids found on the formed concrete surfaces were statistically correlated to the concrete rheology. The permeable lined formwork was shown to produce concrete surfaces with better quality compared to impermeable formwork materials. The same outcome was also noticed for the concrete mixtures having insufficient self-consolidation and even the unstable mixtures that manifested signs of bleeding. The permeable lined formwork was shown to provide an effective way for the entrapped air/water bubbles and the bleed water to escape. The maximum surface dimension of the voids found on the concrete surfaces was limited to 3, 6, 7, and 10 mm for the mixtures cast using the permeable liner, steel, PVC, and plywood formwork materials, respectively.

Poly(vinyl chloride) and its fire properties

SummaryThis work provides an up‐to‐date review of the fire properties of poly(vinyl chloride) (PVC) materials, both rigid (unplasticized) and flexible (plasticized). The fire properties addressed include ignitability, ease of extinction (oxygen index), flame spread (small scale and intermediate scale), heat release, smoke obscuration, smoke toxicity, hydrogen chloride emission and decay, and performance in real‐scale fires.This comprehensive review includes a wide selection of references and tables illustrating the properties of PVC materials in comparison with those of other polymeric materials, including, in many instances, wood materials. The work puts these fire properties in perspective, showing that the heat release rate (the key fire property) of rigid PVC (and that of properly flame‐retarded flexible PVC) are among the lower values found for combustible materials. This work also shows that the smoke toxicity and smoke obscuration resulting from burning PVC materials in real‐scale fires is in the same range as those of other materials.

Tailoring the desired optical and mechanical performance of polyester‐plasticized PVC films: the role of different light stabilizers on the photo‐degradation

Effect of hindered amine light stabilizer (HALS: C944) and ultraviolet absorbers (UVAs: UV326, UV531) on the photo‐stabilities of polyester‐plasticized poly(vinyl chloride) (PVC) and polyester‐plasticized PVC/pigment yellow (PY) films were studied systematically. Both ultraviolet absorbers (UVAs) and hindered amine light stabilizer (HALS) could slow down the discoloration of polyester‐plasticized PVC and polyester‐plasticized PVC/PY films. However, the addition of UVAs protected polyester‐plasticized PVC films from being discolored and its efficiency is higher than HALS. The specific order of stabilizing effect on the photo‐oxidation is UV326 > UV531 > C944. For the optical performance, both UVAs and HALS could help to maintain the transmittance of visible light after photo‐degradation. The former could effectively adsorb ultraviolet (UV) light and resulted in lower transmittance of UV light. For the polyester‐plasticized PVC/PY systems, even though HALS and UVAs cannot help to maintain the shielding ability in high‐energy visible region after UV irradiation, they can help prevent the loss in transmittance of visible light. The surface morphology exhibited small holes on the surface of the films that contain UV531 or UV326; while large and deep holes were observed on the surface of PVC films without additives, C944‐doped and C944/PY‐doped films, indicating the higher UV‐stabilizing effect of UVAs. With regard to mechanical properties, UVAs and HALS can help to prevent the loss. Our present study systematically revealed the role of different stabilizers on the polyester‐plasticized PVC and polyester‐plasticized PVC/PY systems and paved the way to offer PVC materials with functional optical performance and desired long‐term performance using different light stabilizers. Copyright © 2017 John Wiley & Sons, Ltd.

Influence of formwork material on transport properties of self-consolidating concrete near formed surfaces

This study aims at determining the influence of the formwork material on transport properties of concrete cover when using self-consolidating concrete (SCC). Two types of formwork were used. The plywood (PW) formwork material which is relatively rough and absorbent compared to the PVC material that has a very smooth and non-absorbent surface. A total of 17SCC and highly flowable concrete mixtures with wide range of slump flow and T50 values were investigated. The concrete was used to fill 400×500×200mm3 moulds made with either PVC or PW. Sorptivity tests were performed on core samples (100mm in diameter and 50mm in length) taken from the sides and center of the prepared moulds after 28days of moist curing. This paper presents new experimental method using image analysis to quantify the relative surface area of coarse aggregate along different sections near formed surfaces. Sorptivity of concrete near the surface cast against the PW formwork was found to be significantly lower than that of PVC one due to the decrease of local w/c and wall effect. The examination of packing density of coarse aggregate near PVC and PW surfaces showed limited wall effect near the PVC formwork and significant wall effect within a thickness comparable to the maximum size of coarse aggregate near the PW formwork.

Reproducible Superhydrophobic PVC Coatings; Investigating the Use of Plasticizers for Early Stage Biofouling Control

Here we show an easy to synthesize superhydrophobic material using a solvent phase–separation process of poly vinyl chloride. It is found that solvents mixed in different ratios increase the dielectric value of the solvent and can be tuned to produce superhydrophobic PVC. The PVC solution is then spin‐coated onto glass slides for characterization using scanning electron microscopy. Plasticizers are doped into the 70% (v/v) PVC to determine their overall effects; it is found that plasticizers reduce the water contact angle value. The final coatings were tested in a series of antifouling assays in a marine environment lab study; it is found that the superhydrophobic PVC material reduced marine biofouling.