PVC Matrix Research Articles

Flexible PVC materials grafted with castor oil derivative containing synergistic flame retardant groups of nitrogen and phosphorus

Internally plasticized PVC by replacement of chlorine with castor oil derivative containing synergistic flame retardant groups of nitrogen and phosphorus, that is, castor oil derivative grafted onto PVC matrix, is reported. Low glass transition temperature (Tg) of modified PVC was produced although thermal stability was reduced. However, the migration was completely suppressed. The combination of castor oil derivative containing synergistic flame retardant groups of nitrogen and phosphorus with PVC matrix through modifying PVC materials with click reaction prepared flexible PVC materials with zero migration and enhanced flame retardant property.

Study of Ashes from Pachystroma longifolium Leaf as Stabilizer For PVC Exposed to γ‐Irradiation

We describe the use of Pachystroma longifolium (Nees) I. M. Johnst, commonly called canxim, as a radiolytic stabilizer of PVC exposed to γ‐irradiation. Results obtained by viscosity analysis shows that ashes from canxim leaves at the concentration of 0.7 wt% provided macromolecular radioprotective action of 88.2% to the PVC. FT‐IR spectra analysis reveals the existence of specific intermolecular interactions between PVC and canxim ashes. Furthermore, thermogravimetric analysis shows that canxim can also be a potential thermal stabilizer for PVC matrix. Hence, we suggest that canxim have interesting applications in radiolytic and thermal stabilization of PVC.

Polymer induced one-step interfacial self-assembly method for the fabrication of flexible, robust and free-standing SERS substrates for rapid on-site detection of pesticide residues.

We have demonstrated a one-step approach for the fabrication of flexible, robust, reproducible and free-standing SERS substrates (AuNPs/polyvinyl chloride (PVC) film) through a polymer induced interfacial self-assembly method. In this method, the polymer (PVC) plays dual roles, that is, inducing the interfacial self-assembly of nanoparticles and fixing the assembled nanostructure in the PVC matrix. As the assembled nanoparticles are orderly half-embedded in the PVC film, the AuNPs/PVC film exhibits outstanding reproducibility and stability. In addition, the film could be easily regenerated by rinsing with NaBH4 solution. As a proof of concept, the film was directly wrapped on an apple surface for in situ detection of pesticide residues, and a detection limit of 10 ng cm-2 thiram was achieved. Furthermore, rapid on-site and in situ detection of multi-pesticide residues has been proved to be feasible with the aid of a portable Raman spectrometer. Due to its simple preparation, good reliability, outstanding stability and reusability, the AuNPs/PVC film has great potential in practical applications.

Silver nanoparticles incorporated PVC films: evaluation of structural, thermal, dielectric and catalytic properties

Abstract In this work, silver nanoparticle – polyvinylchloride (SNC-PVC) composites were synthesized by loading 2.5% to 10.0% silver ions to PVC using simple solution casting technique. Material properties including dielectric, thermal stability were discussed in some detail. Incorporation of silver nanoparticles (SNPs) in the PVC matrix was confirmed by UV-Visible spectroscopy (UV-Vis), X-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDX) and Field Emission Scanning Electron Microscopy (FE-SEM). FE-SEM confirms the shape of the SNPs are roughly spherical with average size of the SNPs in the range of 60 - 80 nm. The thermal degradation studies were analysed via sensitive graphical Broido’s method using Thermogravimetric analysis (TGA). The resulting SNC-PVC films, especially with 10% silver loading showed improved catalytic performance during the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in the presence of aqueous sodium borohydride with apparent rate constant 1.956 × 10-3 sec-1 at ambient temperature.

Improving the Transport and Antifouling Properties of Poly(vinyl chloride) Hollow-Fiber Ultrafiltration Membranes by Incorporating Silica Nanoparticles

Poly(vinyl chloride) (PVC)/SiO2 nanocomposite hollow-fiber membranes with different nano-SiO2 particle loadings (0–5 wt %) were fabricated using the dry-jet wet-spinning technique. Effects of SiO2 nanoparticles on the morphology of the prepared hollow-fiber membranes were investigated using scanning electron microscopy. Transport and antifouling properties of the fabricated membranes were evaluated by conducting pure-water permeation, solute rejection, and fouling resistance experiments. These studies indicated that incorporating silica nanoparticles into the PVC matrix during phase inversion lowers the hydraulic resistance through the membrane and narrows the selective membrane pores. Moreover, the nanocomposite membranes showed better antifouling properties compared to the pristine membrane during the ultrafiltration of a milk solution because of improved hydrophilicity and uniform dispersion of the nanoparticles. This work indicates that embedding silica nanoparticles into the PVC matrix is a promising method for producing cost-effective hollow-fiber ultrafiltration membranes with superior transport and antifouling properties.

Potentiometric detection of low-levels of sulfamethazine in milk and pharmaceutical formulations using novel plastic membrane sensors

Novel potentiometric sensors for selective screening of sulfamethazine (SMZ) in pharmaceutical preparations and milk samples are reported. The sensor membranes were made from PVC matrix doped with magnesium(II)-, manganese(II)- and dichlorotin (IV)-phthalocyanines as ionophores and aliquat-336 and nitron/SMZ ion-pair complex as ion exchangers. These sensors revealed fast, stable and near-Nernstian anionic response for the singly charged sulfamethazine anion over the concentration range 10-2 - 10-5 M. The sensors exhibited good selectivity towards SMZ over most known anions, excipients and diluents commonly added in drug preparations. Validation of the proposed methods was demonstrated via evaluating the detection limit, linear response range, accuracy, precision (within-day repeatability) and between-day-variability. The sensors are easily interfaced with a double channel flow injection system and used for continuous monitoring of SMZ in drug formulations, spiked milk samples and biological tissues. The method offers the advantages of design simplicity, results accuracy, and automation feasibility.

A simple route to PVC encapsulated Na2SO4·10H2O nano/micro-composite with excellent energy storage performance

A novel Na2SO4·10H2O micro/nanostructure (encap-Na2SO4·10H2O/PVC) encapsulated in poly(vinyl chloride) (PVC) is fabricated via mixing water-dispersible Na2SO4·10H2O micro/nanocrystals with a PVC solution at low temperature. Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) confirm the encapsulation of the Na2SO4·10H2O in the PVC matrix. Thermal analysis showed encap-Na2SO4·10H2O/PVC core-shell structures possess a high latent heat (194.6 J/g) and high stability, and the larger Na2SO4·10H2O cores with thicker PVC shells should improve the heat storage stability of the material. More importantly, the simple, low temperature, and environmentally conscious way for preparing encap-Na2SO4·10H2O/PVC composites may be extended to other promising phase change materials (PCMs).

Evaluation of the antimicrobial, antioxidant and physicochemical properties of Poly(Vinyl chloride) films containing quercetin and silver nanoparticles

This work provides details regarding the physicochemical, antimicrobial and antioxidant properties of poly(vinyl chloride) (PVC)-based films containing 0.4% quercetin and silver nanoparticles (AgNPs) at various concentrations levels. The incorporation of quercetin and AgNPs into the PVC matrix considerably affected the thermal, mechanical and optical properties of the films. Results obtained from the tensile stresgth test, demonstrated an improvement in the mechanical strength of the films after the incorporation of both quercetin and AgNPs. Moreover, an increase in AgNPs concentration increased the rigidity, as compared to control PVC film. Antimicrobial activity against food pathogens (Escherichia coli, Salmonella Typhimurium and Listeria monocytogenes) was evaluated by an antimicrobial barrier test. Results showed that the PVC-based films with quercetin and AgNPs proved to be highly effective to inhibiting bacterial growth. Therefore, these results indicate promising evidence to possibly aid in the prevention of microbial dissemination in foods. Additionally, films incorporated with quercetin and AgNPs expressed an antioxidant capacity when evaluated via the DPPH method. Among all of the films evaluated, the PVC-based films containing 0.4% quercetin and 1% AgNPs were flexible, exhibiting excellent UV-light barrier properties and for use with fatty foods, with the intent of reducing lipid oxidation and preventing food pathogen dissemination.

Venlafaxine Determination in Pharmaceutical Formulation and Serum by Ion-Selective Electrodes.

The application of an ion selective technique for the determination of analyte concentrations is considered one of the most economical techniques for quality control purposes. To elaborate and investigate the construction and general performance characteristics of potentiometric PVC membrane sensors for venlafaxine cation (Ven+). The sensors are based on the use of the ion association complexes of the venlafaxine cation with phosphotungstate (PT) and silicotungstate (ST) counter anions as ion exchange sites in the plasticized PVC matrix. They are characterized by potentiometric and conductimetric measurements, performed under various conditions. The electrodes showed a fast (response time around 15 s), stable (life span 45 days) and linear (r2 0.995) response for venlafaxine over the concentration range of 5x10-5 - 1x10-2 M venlafaxine hydrochloride. The solubility product of the ion pair and the formation of the precipitation reaction leading to the ion pair, were determined conductimetrically. The electrodes were found to be very selective, precise (RSD < 1%) and applicable to the potentiometric determination of venlafaxine hydrochloride in pure solutions or in pharmaceutical preparation and in biological fluid (serum), without any interference. Validation of the method shows the suitability of the proposed electrodes for use in the quality assessment of venlafaxine hydrochloride. Using only a pH meter in combination with the selective electrodes, drug substance or drug product could be determined accurately in a few seconds. In addition, the in-house made electrodes were tested to monitor venlafaxine in serum. Acceptable results were achieved using the standard addition technique.

Thermal, thermomechanical, and morphological characterization of poly(vinyl chloride) (PVC)/ZnO nanocomposites: PVC molecular weight effect

Poly(vinyl chloride) (PVC)‐based nanocomposites containing 2 wt% zinc oxide (ZnO) nanoparticles were prepared by solution casting and the effect of the PVC molecular weight (MW) on the morphology, thermal properties, and thermogravimetric behavior was studied. The addition of ZnO nanoparticles to PVCs of different MWs increased the glass transition temperature (Tg) of the resulting nanocomposites, the extent of which was dependent upon the MW of the PVC matrix. The nanocomposite samples exhibited broadened transition zones as compared with their unfilled PVC matrices. The extent of transition zone broadening was also controlled by the MW of the PVC matrix in the nanocomposites. In the absence of ZnO nanoparticles, the increase in MW of PVC had no effect on the breadth of the transition zone. The TGA results showed that the incorporation of ZnO nanoparticles into PVC matrices of different MWs accelerated the first stage weight loss via the nanoparticle catalytic effect through removal of HCL from the polymeric chains. The presence of ZnO nanoparticles lowered the second stage weight loss, and the char yield obtained for nanocomposites samples was significantly greater than that obtained for neat PVC samples. At low MWs, the presence of ZnO nanoparticles had no effect on the first stage of thermal degradation process. The presence of ZnO nanoparticles in the matrix in different nanocomposites was revealed by SEM observations, and the EDX analysis demonstrated a progressive improvement in the distribution and dispersion state of ZnO nanoparticles in the PVC‐based nanocomposites as the MW of PVC matrix gradually increased. J. VINYL ADDIT. TECHNOL., 25:E63–E71, 2019. © 2018 Society of Plastics Engineers

Unfolding the anticorrosive characteristics of TiO2–WO3 mixed oxide reinforced polyaniline composite coated mild steel in alkaline environment

Electrically conducting polymer incorporated coatings effectively replaced chromate coatings, once widely employed for corrosion deterrence but now strictly restricted due to the environmental hazards. Here polyaniline nanocomposite was prepared by in situ polymerization of aniline monomer in presence of TiO2–WO3 powder, blended with PVC matrix and coated over mild steel specimens to evaluate its anti‐corrosion property in alkaline environment. Structural parameters of the composites and coatings were obtained from XRD and SEM‐EDS studies. Electrochemical parameters that govern the inhibitive efficiency of pigmented steel coupons were explored by Tafel polarization, electrochemical impedance spectroscopy, and open circuit potential measurements. The addition of (0.1 g) 1:1 TiO2–WO3 to PANI (polyaniline) improve the protective efficiency of PANI from 65% to 97.5%. PANI/TiO2–WO3 loaded specimen surface attained a state of passivity through uniform distribution of composite and characterized by the hydrophobic behavior that make it resistive to corrosive environment. Polarization studies identified the composite incorporated PANI as a mixed inhibitor. In order to extend the synthetic utility of prepared pigment, coated specimens are evaluated for their anticorrosive activity in acidic and mixed bacterial culture medium. The present work also included a detailed mechanism of passivation in view of the results of corrosion studies together with available literature studies. POLYM. COMPOS., 40:2400–2409, 2019. © 2018 Society of Plastics Engineers

Thermal, optical, and dielectric investigations of PVC/La0.95Bi0.05FeO3 nanocomposites

This research, reports the effect of La0.95Bi0.05FeO3 nanoparticles incorporation on the thermal, optical and dielectric characteristics of PVC polymer matrix. The PVC/La0.95Bi0.05FeO3 nanocomposites are prepared at RT by means of solution mixing and casting procedure. XRD analysis declared partial crystallinity of pure PVC film, and La0.95Bi0.05FeO3 nanoparticles have an orthorhombic structure. SEM micrographs depicted the uniform surface morphology of PVC film, and La0.95Bi0.05FeO3 nanoparticles are sparsed very well in the PVC matrix. Thermogravimetric analysis revealed that PVC/La0.95Bi0.05FeO3 films with enhanced thermal stability more than pristine film of PVC. The optical energy gaps, Eopt, estimated utilizing Tauc's formula decreased from 5.05 to 4.34 eV while Urbach energy, ΔE, increased with increasing La0.95Bi0.05FeO3 wt%. Dielectric measurements revealed that both the static and high frequency dielectric constants decreased with increasing La0.95Bi0.05FeO3 content. The energy required to move an electron from one site to infinity, WM, increased from 0.66 to 1.46 eV with increasing nanoparticles concentration. Finally, the resonance frequency of PVC/La0.95Bi0.05FeO3 nanocomposite films shifted to lower values and the quality factor decreased with increasing La0.95Bi0.05FeO3 percentage.

ПОЛІМЕР-ПОЛІМЕРНИЙ КОМПОЗИТ ОТРИМАНИЙ ШЛЯХОМ ПЕРЕРОБКИ ВІДХОДІВ ПВХ ЛІНОЛЕУМУ

Development of technology for the processing of mixed waste of vinyl flooring by their joint milling and plasticization. The determination of the MFI was carried out according to ISO 1133: 1997 on a capillary viscometer with a constant pressure and temperature (190 ± 0.5) ° C and a weight of 2.16 kg. The thermostability and melting temperature were determined on the Hipro RM 200C plastograph. Mechanical properties were determined on a breaking machine according to ASTM D638. Hardness - using a Shore D durometer, hydrostatic weighing density on an analytical balance RADWAG AS-X2. Equipment for milling and plasticization of a mixture of PVC / PET waste was selected. Qualitative milling of mixed waste is achieved by using a low speed rotary knife grinder with rotor speed of 300 rpm. The properties of the reinforced PVC were obtained. The strength of this film compared with the classic recipe is lower but when by using such materials in the composition it is possible to obtain a material with high physical and mechanical properties and achieve maximum non-waste production which will also have a positive effect on the economy of the enterprise. The technology for joint processing of mixed vinyl flooring waste was developed for the first time. The features of reinforcing PVC matrix with fibers of a PET was obtained at the receipt of films from mixed vinyl flooring waste. The developed technology allows to provide non-waste production of vinyl flooring at enterprises.

The surface modification of diatomite, thermal, and mechanical properties of poly(vinyl chloride)/diatomite composites

Pristine diatomite was first purified by acid treatment and then modified with γ‐methacryloxy propyl trimethoxysilane molecule (KH570) to introduce hydrophobic chains on the surface of acid‐treated diatomite. Fourier‐transform infrared spectroscopy and thermogravimetric analysis (TGA) indicated that the silane coupling agent (KH570) was successfully grafted on the diatomite through covalent bonding. The digital photos showed that the silanization process changed the surface property of the diatomite. The poly(vinyl chloride) (PVC)/pristine diatomite and PVC/modified diatomite composites were prepared via two‐roll mill. The thermal stability and mechanical properties of PVC composites were investigated by TGA, mechanical properties tests, and dynamic mechanical analysis. The results showed that the thermal stability of the composites improved and maximum weight loss temperature (Tmax) of the PVC composite with 1 phr modified diatomite was about 20°C higher than that of PVC composite without diatomite. The PVC/modified diatomite composites exhibited better mechanical properties owing to the stronger interfacial interaction between PVC matrix and modified diatomite. But the impact strength reduced sharply when the addition of diatomite was more than 1 phr. The reason of the phenomenon is that the diatomite plays the role of defects in PVC and it works against the absorption of impact strength energy. It was proved by the results of scanning electron microscopy. J. VINYL ADDIT. TECHNOL., 25:E39–E47, 2019. © 2018 Society of Plastics Engineers

Facile deposition of polyaniline on the multi-walled carbon nanotubes/polyvinyl chloride composite films as flexible and robust electrodes for high performance supercapacitors

Novel flexible and robust polyaniline/multi-walled carbon nanotubes/polyvinyl chloride (PANI/MWCNTs/PVC) composite films were designed as the free-standing electrodes for high performance supercapacitors, by deposition of polyaniline (PANI) via facile in-situ chemical oxidative polymerization of aniline on the multi-walled carbon nanotubes/polyvinyl chloride (MWCNTs/PVC) composite films, in which MWCNTs were introduced into the PVC matrix in order to improve its mechanical property and electrical conductivity. The MWCNTs/PVC composite film with MWCNTs content of 5% was optimized as the conductive flexible substrate, possessing a tensile strength of 44.1 MPa. The electrochemical tests showed that the PANI/MWCNTs/PVC-2 composite film electrode prepared by the rapid-mixing chemical oxidative polymerization exhibited better electrochemical performance than the PANI/MWCNTs/PVC3-1 composite film electrode prepared by the conventional chemical oxidative polymerization, i.e. specific capacitance of 801.1 F g−1 at a current density of 1 A g−1, rate capacitance retaining 66.6% of its original value at high current density of 10 A g−1 and 54.9% at scan rate of 100 mV s−1, and long-term electrochemical cyclic stability with a retention of 90.6% after 2000 cycles of CV test at a scan rate of 100 mV s−1. Furthermore, the PANI/PVC/MWCNTs-2 film electrode showed excellent tensile and tear-resistance performance and flexibility, indicating its promising application as bendable and robust electrode for energy storage devices.

Effect of Polyhedral Oligomeric Silsesquioxanes Nanoparticles on Thermal and Mechanical Properties of Poly(vinyl chloride) Composite Materials

The modification of poly(vinyl chloride) (PVC) by polyhedral silsesquioxane containing both methacryl and octyl groups (MeOctPOSS) was the task of studies. The PVC nanocomposites with MeOctPOSS concentration between 1 and 10 wt% were prepared by melt mixing processing, and the homogeneity of MeOctPOSS dispersion in the polymeric matrix was confirmed by scanning electron microscopy and energy dispersive spectroscopy observations. The influence of MeOctPOSS on glass transition temperature (Tg) determined by means of dynamic mechanical thermal analysis (DMTA) and differential scanning calorimetry (DSC) was observed, whereas, higher the measurement frequency, higher the glass transition temperature was noted. The MeOctPOSS concentration‐dependent PVC glass transition temperature was shifted from 73.8°C to about 68°C (ƒ = 1 Hz) and from 76.5°C to 70.8°C (ƒ = 10 Hz) for increasing additive content. Similar result of decreasing Tg value was observed by DSC method. An introduction of 10 wt% of MeOctPOSS into the PVC matrix results in a visible decrease of the maximum value of loss modulus (G′) of approximately 12% and 18% by 1 Hz and 10 Hz, respectively, as well as in a significant reduction of the static elastic modulus. It was stated that the polyhedral oligomeric silsesquioxanes with both methacryl and octyl groups may act as plasticizers of the PVC matrix. J. VINYL ADDIT. TECHNOL., 25:E48–E54, 2019. © 2018 Society of Plastics Engineers

Effect of core–shell structures of acrylonitrile–styrene–acrylate (ASA) terpolymer on the properties of poly(vinyl chloride) (PVC)/ASA blends: Miscibility, toughness, and heat resistance

ABSTRACTIn this work, acrylonitrile–styrene–acrylate (ASA) terpolymer was used to toughen rigid poly(vinyl chloride) (PVC). ASA has a core–shell structure, where the poly(butyl acrylate) (PBA) serves as the soft core while styrene‐acrylonitrile (SAN) copolymer works as the rigid shell. Herein, The PBA core content in ASA was varied from 0 to 80 wt %, and its effect on the physiochemical properties was investigated. It was found that the hard shell of ASA was miscible with PVC matrix, providing good interfacial adhesion between ASA and PVC. Increasing the soft PBA content considerably improved the room‐temperature impact toughness, and a sharp brittle–ductile transition (BDT) as a function of PBA content was observed. However, as the testing temperature decreased to 0 and −30 °C, the toughening effect became limited, and the BDT first shifted to high PBA content region and finally disappeared. It was suggested that whether the toughening effect can be achieved depended on the thickness of hard shell and the relaxation behavior of PBA core. Albeit the loss in rigidity was accompanied, the accomplished toughening effect was not on the sacrifice of heat distortion temperature. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46839.

Comprehensive study on reinforcement of poly(vinyl chloride) nanocomposite films with ZnO nanoparticles modified by citric acid and vitamin C

We reported a general facile approach for modifying NPs and incorporating them into PVC polymer via ultrasonic irradiation. ZnO nanoparticles (NP)s modified with ascorbic acid (AS) and citric acid (CA) were employed to investigate the agglomeration behavior under poly(vinyl chloride) PVC matrix. To compare and determine the suitable construction, the prepared PVC/ZnO-CA-AS NCs (4, 8, 12 wt%) were characterized. UV-visible measurements indicate, increasing absorption value results in an increase of ZnO content. According to the obtained information from the TGA of the NCs, further increases in modified ZnO results in an increase in flame-retardancy. The mechanical properties investigation revealed improvement of the elongation at maximum stress.

Synthesis and Characterization of Molecularly Imprinted Polymer for Tramadol Hcl Using Acryl Amide and 2-Hydroxyethyl Meth Acrylate as Monomers

Abstract Four electrodes were synthesized based on molecularly imprinted polymers (MIPs). Two MIPs were prepared by using tramadol hydrochloride (TRH) as the template, acryl amide (AA) and 2-hydroxy ethyl meth acrylate (2-HEMA) as monomers, divinyl benzene as a cross linker, and benzoyl peroxide as initiator, respectively. The same composition was used to prepare non-imprinted polymers (NIPs), but without the template (Tramadol hydrochloride). Different plasticizers were employed to prepare the membranes; tris (ethyl hexyl) phosphate (TEHP), tri Butyl phosphate (TBP), di-octyl phthalate (DOP) and nitrobenzene (NB) in PVC matrix. The electrode characteristics and properties were studied, including: slope, detection limit, life time and linearity range. The results of selectivity coefficient measurements using amino acids as interfering species showed no effect on tramadol electrode response. The prepared electrodes were intended for use in determining tramadol in pharmaceutical samples

A Sensitive Electrochemical Sensor for Rapid Determination of Mebeverine Hydrochloride and Metronidazole Benzoate Selective Molecular Imprinted Polymer in the PVC Membrane

By using precipitation polymerization, liquid electrodes of polymers imprinted with Mebeverine hydrochloride and metronidazole benzoate were created whereas the imprinted polymer (MIP) and non imprinted (NIP) polymers were prepared by using Mebeverine hydrochloride and Metronidazole benzoate qua a template. In the polymerization process, 2-Acrylamido-2-methyl-1-propane Sulphonic acid (AMPS) or 1-Vinylimidazole (VIZ) was used qua monomer, pentaerythritol triacrylate (PETRA) or Divinylbanzene (DVB) was used qua a cross-linker while benzoyl peroxide (BPO) was used as an initiator. The MIP membranes and the membranes of NIP were created by using Dibutyl Sebacate (DBS) and Tris(2-ethylhexyl)phosphate(TEHP) qua plasticizers in PVC matrix. The response time of the liquid electrodes was 1min. whereas their slopes and detection limits reached to 19.62 – 57.36 mV per decade and 1.2 x 10-6 – 2.0 x 10-5 M, respectively. Filling with standard solution of drug (0.1M), the liquid electrodes response -with suitable No.( selectivity for numerous of species - was suitable No.( since pH reached to 1.5 – 12. The developed electrodes were successfully applied for the analyte determination in preparation pharmaceutical sample without any time consuming pretreatment steps.