Industrially-viable nonmigratory internal plasticization of poly(vinyl chloride) (PVC) is achieved by synthesis of the block copolymer poly(vinyl chloride)-b-poly(n-butyl acrylate)-b-poly(vinyl ...chloride) (PVC-b-PBA-b-PVC) by aqueous single electron transfer degenerative chain transfer living radical polymerization (SET-DTLRP). The introduction of a temperature step (42 °C to 80 °C) in the synthesis of PVC-b-PBA-b-PVC block copolymers from PBA macroinitiators resulted in materials with better overall performance than the commercial flexible PVC. The resulting copolymers were fully characterized by 1H NMR, SEC, SEM, TGA, DSC and DMTA to determine the composition, molecular weight, dispersity, morphology, thermal and mechanical properties, and compared with those of commercial formulations prepared with PVC and dioctyladipate (DOA). Most importantly, the plasticizing moieties of the PVC-b-PBA-b-PVC block copolymers are covalently bonded to the polymer, resulting in no migration upon extraction under conditions where DOA is readily extractable. Unlike commercial materials, the PVC-b-PBA-b-PVC block copolymers showed that the properties remain intact after extraction with n-hexane.
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•The industrially-viable new strategy is proposed in the synthesis of PVC-b-PBA-b-PVC block copolymers by aqueous SET-DTLRP.•PVC-b-PBA-b-PVC block copolymers result in better overall performance materials than the commercial flexible PVC.•Nonmigratory internal plasticization PVC is achieved and proved without loss of PVC-b-PBA-b-PVC properties with migration resistance.
Gamma irradiation exhibits a complex influence on the properties of PVC/PANI/TiO2 nanocomposite films. XRD analysis reveals a non-monotonic response in crystallinity, with an initial increase at ...lower doses due to crosslinking followed by a decrease at higher doses attributed to polymer chain scission. Mechanical properties exhibit an improvement in tensile strength and Young's modulus at moderate doses (up to 100 kGy) due to crosslinking. However, excessive irradiation (>100 kGy) induces chain degradation, causing a decrease in both tensile strength and elongation at break. Similar dose-dependent behavior is observed in thermal properties, with moderate doses improving thermal stability and melting temperature before a decline at higher doses due to chain degradation. Gamma irradiation significantly affects AC conductivity, suggesting potential changes in structure, charge carrier density, and conduction mechanisms. While the core chemical structure remains largely unaffected, FTIR and UV–Vis spectroscopy analyses indicate alterations in the degree of crosslinking and optical properties, warranting further investigation. Refractive index increases with irradiation due to enhanced density and changes in polarizability. This study highlights the importance of tailoring the gamma irradiation dose to achieve desired properties in PVC/PANI/TiO2 nanocomposite films for various applications.
•γ-Irradiation tailors crystallinity of nanocomposites.•Moderate doses enhance strength & stiffness.•Optimized thermal stability for heat resistance.•Tuned electrical conductivity for electronics.•Balanced optics for light & refractive index.
The physical damage of engineering materials is challenging to perceive, particularly when they occur with only a slight extent. To present the location of damage to engineering is still difficult to ...achieve. Mechanical responsive engineering materials are therefore highly desired. Herein, a type of composites comprised of carbon nanoparticles (CNP) and poly(vinyl chloride) (PVC) was prepared via a heating incubation process. Notably, we found that these composites were in a metastable state and exhibited a grinding-stimulated fluorescence enhancement performance. After grinding stimulation, a bright orange-yellow color emission appeared and the fluorescence intensity of the composites exhibited a 75-fold enhancement. It was noted that grinding had no effect on the fluorescence of CNP alone. The fluorescence enhancement may be due to the change in the surface environment of CNP, as grinding facilitates the entry of CNP into PVC. In addition, fluorescence enhancement was also observed in tightening screw experiments using commercialized PVC films, demonstrating the abrasive-stimulated fluorescence enhancement properties of this CNP/PVC. Such remarkable mechanical response property and interesting combination between CNP and PVC will provide avenue to promote the development of smart engineering materials and have considerable potentials in external force response and structure damage surveying.
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•Synthesis of a mechano-fluorescence responsive carbon nanomaterial by solvothermal method and heating incubation.•The material showed a 75-fold fluorescence enhancement when stimulated by grinding.•Mechanisms of the mechanical fluorescence response of composites are explored.•A strategy for force-induced fluorescence response has been developed to expand the applications of carbon nanomaterials and PVC.
•A novel photodegradable Nano-G/TiO2/PVC composite film was prepared by codoping nano-graphite and TiO2 photocatalyst in the PVC plastic.•The Nano-G/TiO2/PVC composite film shows the excellent ...photodegradability.•The mechanism of the Nano-G/TiO2/PVC composite film photocatalytic degradation was proposed.•The photodegradable Nano-G/TiO2/PVC composite film is one of the feasible and effective methods to solve "white pollution".
A novel photodegradable Nano-G/TiO2/PVC composite film was prepared by codoping nano-graphite (Nano-G) and TiO2 photocatalyst in Polyvinyl chloride (PVC) plastic. The Characterization tests were performed by using ultraviolet-visible spectroscopy (UV-vis), infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), gel permeation chromatography (GPC) and physical and mechanical properties. Compared with TiO2/PVC, Nano-G/PVC and PVC film, the Nano-G/TiO2/PVC composite film showed higher photodegradability. The weight loss rates of Nano-G/PVC (Nano-G 1 wt%), TiO2/PVC (TiO2 1 wt%) and Nano-G/TiO2/PVC (Nano-G 1 wt%, TiO2 1 wt%) films after the UV irradiation for 30 h were 7.68%, 8.94% and 17.24%, respectively, while that of PVC was only 2.12%. For the Nano-G/TiO2/PVC composite film, the optimal doping amount of nano-graphite is 1 wt%. The decline rates of Mw and Mn of Nano-G/TiO2/PVC (Nano-G 1 wt%, TiO2 1 wt%) composite film were 12.93% and 61.97%, respectively, which were much higher than that of PVC. Nano-graphite can effectively improve the migration and separation of TiO2 photogenerated electrons, improving the photodegradation rate of PVC. The mechanism of the Nano-G/TiO2/PVC composite film photocatalytic degradation was proposed. The photocatalytic technology is a feasible and effective way to solve "white pollution".
Photoresponse of the Au/(Er2O3:PVC)/n‐Si diode was executed in a wide range of illumination intensity (P). Its basic electrical parameters such as ideality factor (n), barrier height (ΦB0), series ...and shunt resistances (Rs, Rsh), photocurrent (Iph), energy‐dependence of interface states (Nss), and photosensitivity (S) were calculated from the results of the current–voltage (I–V) measurements. At the negative‐bias region, an increase in Iph is observed due to the e−‐h+ pairs that occur as a result of increasing P and their drift in opposite directions under the internal electric field. The ln(Iph)–ln(P) plot shows a good linear behavior under various applied voltages. Their slopes vary from 1.47 to 1.64, indicating that empty trap levels, that is, levels not occupied by charges, are of low density. The values n, ΦB0, and Rs were obtained using the thermionic emission theory, Cheung, and Norde functions. The value of ΦB0 decreases with increasing n and P as linearly with ΦB0(n) = (−0.143n + 1.118) eV and ΦB0(P) = (−2 × 10−4P + 0.831) eV, respectively. This illumination coefficient of ΦB0 (=−2 × 10−4 eV/mW/cm2) is close to the temperature coefficient bandgap of Si (=−4.73 × 10−4 eV/K). These results show that the performed Au/(Er2O3:PVC)/n‐Si diode has excellent photo‐response and can be successfully used in photovoltaic applications instead of conventional metal–semiconductor diodes.
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•Antifouling PVC/PVC-g-PEGMA blend ultrafiltration membranes were first fabricated.•The effect of 5–20 wt.% PVC-g-PEGMA on PVC membrane properties was investigated.•Addition of ...PVC-g-PEGMA increased the hydrophilicity of the membrane surface.•Adding PVC-g-PEGMA increased pure water flux and maintained high SA rejection ratio.•Optimal addition of PVC-g-PEGMA was 10 wt.%, increasing flux recovery ratio by 89%.
To improve the performance of poly(vinyl chloride) (PVC) membranes, we synthesized the amphiphilic copolymer PVC-graft-poly(ethylene glycol) methyl ether methacrylate (PVC-g-PEGMA) via atom transfer radical polymerization (ATRP). We then fabricated PVC/PVC-g-PEGMA blended ultrafiltration membranes for the first time. The effect of the amount of PVC-g-PEGMA from 5 to 20 wt.% on the PVC membrane properties was systematically investigated. The successful synthesis of PVC-g-PEGMA was confirmed by the results of nuclear magnetic resonance (1H NMR), and Fourier transform infrared spectroscopy (FTIR). With the increase in the amount of the PVC-g-PEGMA additive from 0 to 20 wt.%, we found that (1) the surface oxygen content of the membrane increased from 3.20% to 9.31%; (2) the membrane surface pore size and pore density decreased; (3) the hydrophilicity and pure water flux of the membrane improved, but they plateaued, even slightly decreasing after the addition of 15 wt.% PVC-g-PEGMA; (4) the sodium alginate (SA) rejection ratios of all PVC/PVC-g-PEGMA blended membranes were higher than 90%; and (5) all blended PVC membranes exhibited higher flux recovery ratios (FRRs) than the pure PVC membrane; in particular, the FRR increased by 89% when 10 wt.% PVC-g-PEGMA was added. These results indicated the enhanced antifouling properties of PVC/PVC-g-PEGMA blended ultrafiltration membranes.
Phthalates are ubiquitously present environmental contaminants. Air and dust are the most important mediums of exposure to phthalates. The present study reviews the presence of phthalates in the air ...and dust reported from different countries in the last ten years (2007–2017). The phthalate concentrations revealed wide heterogeneity with a mean and median value 6 ± 19 μg/m3 and 0.5 μg/m3 respectively in the air and 1.5 × 103 ± 2.2 × 103 μg/g and 7.8x102μg/g respectively in the dust. The highest phthalates levels in the air were reported from India (1.1 × 102 μg/m3) and in dust from Bulgaria (1.2 × 104 μg/g). Overall higher levels were reported from developing countries as compared to developed countries. Di (2-ethylhexyl) phthalate (DEHP) and Di-n-butyl phthalate (DBP) were found to be predominant in both air and dust. Temperature, humidity, air exchange rate, building material and indoor maintenance were reported as the important factors influencing the levels of phthalates in the air and dust. In addition to policy level interventions, reducing the use of phthalate containing materials and controlling the factors which enhance the emission from existing sources can help in reducing human exposure to phthalates.
Graphical representation of the occurrence of phthalates in air and dust. Display omitted
•Global phthalate levels in the air and dust along with factors associated with their presence were reviewed.•Asian countries were found to contain the highest level of phthalates.•DEHP and DBP were found to be predominant in both air and dust.•Temperature, air exchange rate and use of PVC materials were found to be strongly associated with presence of phthalates.
In this research, a carbothioamide derivative molecule was synthesized to be used as an electroactive material, and poly (vinyl chloride) (PVC) membrane lead(II)–selective potentiometric sensors with ...different components were prepared. Among various compositions, the best potentiometric performance was exhibited by the membrane having the electroactive material, bis(2–ethylhexyl)sebacate (BEHS), PVC, and potassium tetrakis(p–chlorophenyl)borate (KTpClPB) in the ratio of 4.0:63.0:32.0:1.0 (w/w). The proposed sensor exhibited a Nernstian response in the concentration range of 1.0×10-5–1.0×10-1 mol L-1 with a slope of 29.5±1.6 mV/decade. The detection limit of the sensor was 3.96×10-6 mol L-1. The potentiometric response of the lead(II)–selective sensor was independent of pH of test solution in the pH range of 5.0–9.0. The developed sensor had very good repeatability, stability, and selectivity, as well as a response time of 5s. These novel lead(II)–selective sensors, produced cost–efficiently, have been successfully used as an indicator electrode for the potentiometric titration of Pb(II) against EDTA and for the determination of Pb(II) ions in different water samples.
Rigid PVC plastics (R-PVC) contain large amounts of chlorine, and improper disposal can adversely affect the environment. Nevertheless, there is still a lack of sufficient studies on hydrothermal ...treatment (HTT) for the efficient dechlorination of R-PVC. To investigate the migration mechanism of chlorine during the HTT of R-PVC, R-PVC is treated with HTT at temperatures ranging from 220 °C to 300 °C for 30 min to 90 min. Hydrochar is characterized via Fourier transform infrared spectrometry and X-ray photoelectron spectroscopy. The results revealed that the hydrothermal temperature is the key factor that affects the dechlorination of R-PVC. Dramatic dechlorination occurs at temperatures ranging from 240 °C to 260 °C, and the dechlorination efficiency increases with the increase in the hydrothermal temperature. The main mechanism for the dechlorination of R-PVC involves the nucleophilic substitution of chlorine by -OH. CaCO3 can absorb HCl released by R-PVC and hinder the autocatalytic degradation of R-PVC; hence, the dechlorination behavior of R-PVC is different from that of pure PVC resins. Based on these results, a possible degradation process for R-PVC is proposed. This study suggests that HTT technology can be utilized to convert organochlorines in R-PVC to calcium chloride, achieving the simultaneous dechlorination of R-PVC and utilization of products.
The current study focuses on the fabrication of hybrid flexible polymers composed of MnFe2O4/ZnMn2O4 nanocomposites doped polyvinyl chloride (PVC). The doped polymers show great potential for ...utilization in a wide range of optoelectronics applications. PVC/(1-x)MnFe2O4/xZnMn2O4 were made using the casting and sol gel processes. The effect of (1-x)MnFe2O4/xZnMn2O4 nanocomposite samples on the optical parameters of PVC polymer has been explored using ultraviolet–visible diffused reflectance measurements. Doped polymers might be useful as protective barriers against ultraviolet radiation of various wavelengths (UVA, UVB, UVC) and as excellent absorber materials for solar cells. The direct and indirect bandgaps (Eg) of PVC are 4.26 and 4.08 eV. The direct/indirect optical band gap lowered to their lowest 3.97/3.45 eV as the PVC doped with nanofillers contained 50 %/80 % ZnMn2O4, respectively. Different models were used to extracted the refractive index (n) of different polymers based on the obtained optical band gaps (direct/indirect). Doped polymers containing 50 and 80 % ZnMn2O4 had the highest n values using direct and indirect Eg values, respectively. The n value (obtained from the direct optical bandgap energy) of PVC increased from 2.209 to the maximum value (2.262) as x = 0.5. The n value (obtained from the indirect optical bandgap energy) of PVC increased from 2.349 to the maximum value (2.367) as x = 0.8. All linear and nonlinear optical parameters of PVC polymer were improved as it doped with the nanocomposite fillers. The fluorescence (FL) intensity of PVC was reduced as it was doped with (1-x)MnFe2O4/xZnMn2O4 and this intensity reduced as the content of ZnMn2O4. The standard (CIE) color space chromaticity diagram was used to analysis the FL spectra for different samples. The effect of nanocomposite samples on the AC conductivity, dielectric constants and electric modulus of the PVC was studied. At 1 kHz, the dielectric constant of PVC was increased from 11.745 to 12.906 and 12.096 for polymers with x = 0 and x = 0.2, respectively. The enhanced optical and dielectric properties of the PVC/(1-x)MnFe2O4/xZnMn2O4 polymers nanocomposites suggest that these materials are suitable for smart electronic devices.
•Adding (1-x) MnFe2O4/x ZnMn2O4 to PVC led to an irregular changes in absorbance and transmittance spectra.•Doped PVC nanocomposite with 80 % ZnMn2O4 has the greatest optical conductivity value.•The decline in FL emission intensity nominated the doped polymer as a prime candidate for photocatalytic uses.•Increases in dielectric constant and AC conductivity were seen for PVC doped with MnFe2O4 alone.•The amount of ZnMn2O4 in the nanocomposite fillers slightly affected the relaxation time of the PVC.
