Polymerization Of Vinyl Chloride Research Articles

Synthesis and Antibacterial Activity of Grafted Poly(Vinyl Chloride) Polymer against Gram-Positive and Gram-Negative Bacteria

Infectious diseases caused by microorganisms have gained worldwide attention in recent years. According to data compiled by the World Health Organization, the number of deaths resulting from infectious diseases is on the rise. In light of these dangers, the study of antibacterial materials has become increasingly vital. In this research, an antibacterial polymer was developed using poly(vinyl chloride) (PVC) and 4,4-diamminodiphenylmethane (DDM). The produced polymer’s chemical structure and thermal properties were investigated using Fourier-transform infrared spectroscopy, nuclear magnetic resonance, and thermo-gravimetric analysis. The antibacterial activity of the resulting PVC-g-DDM polymer was effective in killing both Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. The antimicrobial efficacy was tested using a spread plate method, demonstrating its potential utility in a variety of applications like biomedical, coatings, water purification systems, and others. Antimicrobial resistance is increasing, especially among bacteria that have acquired resistance to multiple therapeutics. To fully optimize and explore the polymer’s potential and its usage, more research is needed.

Optical structural and thermal studies of TiO2@ZnO core-shell incorporated methylene blue dye doped PVA polymer nanocomposites

This manuscript makes an effort to achieve the synthesis of titanium dioxide (TiO2)@ Zinc oxide (ZnO)core@shell also development and study of methylene blue (MB)/TiO2@ZnO/poly(vinyl chloride) (PVA)polymer nanocomposites (PNCs) for optical applications. The PNCs were constructed using easy solution-casting method, advertised good UV–vis and fluorescence properties. The fluorescence emission spectra of MB/TiO2@ZnO/PVA PNCs show the broad peak around 685 nm for both 614 nm and 665 nm excitation wavelengths for all samples and it is observed that the intensity falls off as increase in the dye amount. The x-ray diffraction (XRD) spectra of well-developed PNCs exhibit amorphous nature and the other outcomes obtained by various techniques correlating with each other. Hence, the prepared PNCs can be used for fabricating red light emitting diode (LED) to improve the eye sight of human being.

U.S. plastic waste exports: A state-by-state analysis pre- and post-China import ban

This study analyzes the regional implications of China's 2017 import ban on plastic waste by examining U.S. census data. A statistically significant decrease in total U.S. plastic waste exports was found, dropping from about 1.4 million tons to 0.6 million tons in the post-ban period. California remained the top exporter, throughout both pre- and post-ban periods, while South Carolina exhibited the highest per capita exports. Malaysia emerged as the largest importer of U.S. plastic waste, followed by Vietnam, Indonesia, and Thailand. The ban also led to a change in the composition of the exported plastic waste. Ethylene polymers increased from 32.6% of total exports in the pre-ban period to 46.9% in the post-ban period. Other plastics (vinyl chloride polymers, styrene polymers, and for plastics not elsewhere specified or included) decreased from 67.4% of total exports in the pre-ban period to 53.1% in the post-ban period. Moreover, we found that exporting plastic waste has significant environmental and human health impacts. For example, the Global Warming Potential (GWP) decreased from 20 million tons CO2-eq in the scenario where 100% of plastics are exported, or 25 million tons exported from the U.S. since 2002, to −11.1 million tons CO2-eq in the scenario where 100% of plastics are treated domestically. Transportation exacerbates these impacts for exported waste scenarios, increasing to 5.4 million tons CO2-eq when plastics are exported by ship while decreasing to 0.9 million tons CO2-eq for domestic treatment. Although exporting plastic waste is initially cost-effective, our study highlights that investing in domestic waste management can yield significant long-term benefits, considering the environmental and public health impacts. Therefore, it is crucial to prioritize context-specific solutions to address the challenges of the evolving global plastic waste landscape.

An Investigative Study on the Structural, Thermal and Mechanical Properties of Clay-Based PVC Polymer Composite Films.

The present study aims to explore the impact of pristine and surfactant-modified clays (montmorillonite, bentonite and vermiculite) on the thermomechanical properties of a poly (vinyl chloride) (PVC) polymer film. Initially, clay was modified by employing the ion exchange method. The modification of clay minerals was confirmed by the XRD pattern and thermogravimetric analysis. Pristine PVC polymer film and clay (montmorillonite, bentonite and vermiculite)-based PVC polymer composite films were fabricated using solution casting. The ideal dispersion of surfactant-modified organo-clays was observed in the PVC polymer matrix due to the hydrophobic nature of modified clays. The resultant pure polymer film and clay polymer composite film were characterized using XRD and TGA, and their mechanical properties were determined using a tensile strength tester and Durometer. From the XRD pattern, the intercalation of the PVC polymer film was found in the interlayer of organo-clay while exfoliation or partial intercalation and exfoliation were observed for pristine clay mineral-based PVC polymer composite films. Thermal analysis indicated a lowering of the decomposition temperature of the composite film as clay promotes the thermal degradation temperature of PVC. Improvement in the tensile strength and hardness was found to be more frequent in the case of organo-clay-based PVC polymer films, which is only due to the hydrophobic nature of organ clays, resulting in greater compatibility with the polymer matrix.

Poly(vinyl chloride) Derived Food Packaging Applications with Antioxidative and Anticancer Properties

Novel poly(vinyl chloride) (PVC) polymer derivatives based on the natural antioxidants vanillic acid, cinnamic acid, coumaric acid, caffeic acid, and naringin were prepared and characterized for their chemical structures, molecular weights, thermal and mechanical properties, and antioxidant characteristics toward linseed oil. Oxidation delay times (induction periods) were prolonged from 1 to 6 days beyond the pristine PVC, with the naringin-based derivative being the most effective. Biological activities of the PVC derivatives were determined and showed the substituted PVC polymers effectively inhibited the formation of reactive oxygen species (ROS) in the MCF-7 cell line according to the following sequence: cinnamic acid ≥ caffeic acid ≥ vanillic acid = naringin ≥ coumaric acid, with only a minimal effect on healthy L929 cells. These results indicate that the derivatives produced in this study have potential applications as active packaging materials for food and as antibacterial/anticancer biomaterials in areas such as tissue engineering.

Self-Stabilized Precipitation Polymerization of Vinyl Chloride and Maleic Anhydride

Self-Stabilized Precipitation Polymerization of Vinyl Chloride and Maleic Anhydride

Novel Role of Hemeoxygenase-1 in Phthalate-Induced Renal Proximal Tubule Cell Ferroptosis.

Phthalates are widely used to improve the flexibility of poly(vinyl chloride) (PVC) polymer agriculture products. Di(2-ethylhexyl) phthalate (DEHP) is a type of addition to plastic and can lead to many health problems. Hemeoxygenase-1 (HO-1) is an extremely important molecule that releases enzymatic products to promote ferroptosis. This research aimed to explore the function of HO-1 in DEHP-induced renal proximal tubule cell ferroptosis. In the experiment, ICR male mice are exposed to (0, 50, 200, and 500 mg/kg BW/day) DEHP for 28 days. Here, we observed that DEHP induced glomeruli atrophy and the tubules swell. Furthermore, DEHP exposure could increase ferrous iron content and decrease antioxidant activity. We also found that DEHP exposure increased the expression of nuclear factor-erythroid 2 p45-related factor 2 (NFE2L2) in the nucleus. In particular, the expression of (HO-1) is significantly increased both in protein and mRNA levels. Glutathione peroxidase 4 (GPX4) as an endogenous control of ferroptosis was downregulated, which proved the occurrence of ferroptosis. In the study, exposure to DEHP activated the NFE2L2/HO-1 signaling pathway and resulted in ferroptosis of the proximal tubule. This research connects ferroptosis with HO-1, providing new insights into the potential roles of phthalates in nephrotoxicity.

Studies on thermo-mechanical properties of HNTs filled ABS/PVC composites

In present work, Acrylnitrile-Butadiene-Styrene (ABS) copolymer and Poly Vinyl Chloride (PVC) polymers have been blended with injection molding technique. To improve the thermo-mechanical properties of ABS/PVC blend, Halloysite Nanotubes (HNTs) at different concentration like (0, 0.5, 1, 1.5 and 2 wt%) also added. To obtain the best results, the percentage concentration of PVC is maintained at 10 % in ABS. The results of this work showed that due to addition of HNTs up to 1.5 wt% tensile and impact properties improve by 71.73 % and 32.6 % respectively. In addition to this, HNTs also showed the improved thermal stability of composites which is explained with the help of Differential Scanning Calorimetry (DSC). ABS/PVC composites will find applications in the piping and electrical insulation systems.

In situ suspension polymerization of vinyl chloride/3-(trimethoxysilyl) propyl methacrylate (MPTMS)-intercalated Mg-Al-hydroxide layered double hydroxide: I. Grain properties

Suspension polymerization of vinyl chloride (VCM) was carried out in the presence of particle of both pristine Mg-Al layered double hydroxide (LDH) and LDH intercalated by 3-(trimethoxysilyl) propyl methacrylate (MPTMS-LDH) in a pilot-scale reactor. The experiments were conducted at different concentrations of each type of the particles (0, 1, 3, 5, 7 wt. % of VCM). The pure LDH and MPTMS-intercalated LDHs were used as co-monomer for fabrication of LDH or MPTMS-LDH/PVC nanocomposites; the particles were directly pre-dispersed in monomer phase before dispersing in the continuous aqueous phase and starting the suspension polymerization. The basal spacing obtained from the X-ray powder diffraction (XRD) showed that the reaction between VCM and MPTMS-LDH was effective, with a further intercalation of PVC chains in the interlayer space. The molecular characterization showed that the polydispersity index (PDI) and molecular weight of the poly (vinyl chloride) (PVC) resin do not change in the presence of the pristine LDH. The MPTMS-LDH, however, decrease the molecular weight and increase the PDI of PVC resin. Also, from the morphological point of view, scanning electron microscopy (SEM) showed that PVC grains produced with high particles content had a smoother surface with more regular shape. Moreover the incorporation of nanoparticles in the VCM suspension polymerization, made particles with a narrower size distribution. The LDH results in the formation of smaller primary particles with higher internal porosity whereas, the larger primary particles with lower internal porosity in the presence of modified particles was observed.

Influence of polystyrene modifier on features of polyvinylchloride plastics production

The main methods of physical modification of PVC materials is the combination with other polymers, including PS plastic, and the creation of polymer (nano) composites containing metal and silicate fillers. Modification of polyvinyl chloride by polystyrene plastic leads to obtain materials with reduced degree of plasticizer release out of matter volume, adjustable elastic-plastic characteristics, and enhanced physico - mechanical and thermal properties. Physical modification of vinyl chloride polymers by other polymers or nanoscale particles of inorganic nature enables predictable affect on the morphology of these materials and directed regulate their technological and performance properties.

Kinetics of poly(vinyl chloride) thermal degradation by ionizing radiation

In this study, the relationship between ionizing radiation treatment and thermal degradation kinetics of Poly (vinyl chloride) (PVC) polymer film was investigated. The unirradiated and 25 kGy irradiated samples treated with gamma rays or electron beam radiation were submitted to thermogravimetric analysis (TGA) at different heating rates (10 – 30 K.min-1). The TGA data was used to obtain the apparent activation energy values (Ea) according to Flynn-Wall-Ozawa method. TGA analysis suggested that electron beam radiation promotes a slight increase on maximum temperature for dehydrochlorination reaction on PVC. Gamma-rays irradiation caused a small reduction of maximum temperature of HCl evolution of PVC. Thermal degradation kinetics results showed that 25 kGy irradiated samples presents an apparent activation energy values from 104 - 109 KJ.mol-1. The apparent Ea values suggested that 25 kGy gamma radiation or 25 kGy electron beam radiation convert PVC polymer films more prone to HCl evolution due to radiolysis of polymer. Evaluation of the Ea values by Flynn-Wall-Ozawa method allows a good analytical instrument to comprehend dehydrochlorination reaction on irradiated PVC polymer films.

Kinetics of poly(vinyl chloride) thermal degradation by ionizing radiation

In this study, the relationship between ionizing radiation treatment and thermal degradation kinetics of Poly (vinyl chloride) (PVC) polymer film was investigated. The unirradiated and 25 kGy irradiated samples treated with gamma rays or electron beam radiation were submitted to thermogravimetric analysis (TGA) at different heating rates (10 – 30 K.min-1). The TGA data was used to obtain the apparent activation energy values (Ea) according to Flynn-Wall-Ozawa method. TGA analysis suggested that electron beam radiation promotes a slight increase on maximum temperature for dehydrochlorination reaction on PVC. Gamma-rays irradiation caused a small reduction of maximum temperature of HCl evolution of PVC. Thermal degradation kinetics results showed that 25 kGy irradiated samples presents an apparent activation energy values from 104 - 109 KJ.mol-1. The apparent Ea values suggested that 25 kGy gamma radiation or 25 kGy electron beam radiation convert PVC polymer films more prone to HCl evolution due to radiolysis of polymer. Evaluation of the Ea values by Flynn-Wall-Ozawa method allows a good analytical instrument to comprehend dehydrochlorination reaction on irradiated PVC polymer films.

One-pot polyvinyl chloride preparation utilizing polyacrylate latex with tertiary amine groups for improved thermal stability, toughness, and reduced reactor scaling

In this paper, crosslinked polyacrylate latex with tertiary amine groups (ACLN) and base latex without tertiary amine groups (ACL) were prepared by emulsion polymerization using butyl acrylate as the monomer and 1,4-butanediol dimethacrylate as the crosslinker. Composite resins of polyvinyl chloride (PVC), ACL/PVC and ACLN/PVC, were prepared by suspension polymerization of vinyl chloride in a 20 L high-pressure reactor by adding ACL and ACLN as modifiers. The inner pressure of the reactor and initiator concentration as a function of reaction time during suspension polymerization were studied. Morphology of resin particles, processing properties, thermal stability and mechanical properties of ACL/PVC and ACLN/PVC products were investigated. A commercial PVC product named PVC-SG5 was used as the control sample for comparison. It was found that compared with typical PVC-SG5 preparation, ACL/PVC fabrication took less time while initiator concentrations needed to be increased to 2400 ppm in ACLN/PVC preparation in order to complete the polymerization within the same time. Reactor scaling occurred during ACL/PVC preparation, but could be avoided in ACLN/PVC preparation owing to the hydrophilicity of ACLN. The morphology of ACL/PVC and ACLN/PVC particles was smooth microspheres and mosaic particle shapes, respectively, the diameter of which were all smaller than PVC-SG5 particles. The covalent-bonding existing in ACL/PVC and ACLN/PVC, and ionic-bond formation of quaternary ammonium in ACLN/PVC composite resins, between tertiary amine groups in ACLN and chlorine atoms in PVC, contributed to the dramatic increase in thermal stability. ACLN/PVC exhibited the shortest plasticizing time and the longest elongation at break, followed by ACL/PVC. The toughness of both ACL/PVC and ACLN/PVC were greatly enhanced without affecting the tensile strength and softening temperature of the resin. Thus, three issues, namely, low thermal stability, low toughness and reactor scaling during polymerization of PVC have been comprehensively solved by introducing ACLN to PVC through a one-pot method.

Proton spin relaxation study with pulsed NMR on the plasticization of Na+ ion-selective electrode membranes prepared from PVCs with different degrees of polymerization.

The proton spin-spin relaxation times (T2) of ion-selective electrode membranes with differences in the polymerization degree of the incorporated poly(vinyl chloride) (PVC) polymers were investigated. T2 measurements were performed using Hahn-Echo, Solid-Echo and Carr-Purcell-Meiboom-Gill (CPMG) pulse sequences. Analyses of the T2 measurements by Hahn-Echo pulse sequences could realize the estimation of the homogeneity and compatibility for a series of ion-selective electrode membranes and reveal a relationship with the electromotive force (EMF) response in the low-concentration region of the Na+ ions. On the other hand, the normalized derivative spectra from T2 measurements by Solid-Echo and CPMG pulse sequences could approximately visualize the degree of plasticization for such potentiometric polymeric membranes. Moreover, differences in the polymerization degrees of the incorporated PVCs were scarcely found to affect the selectivity coefficients of the Na+-ISEs based on bis(12-crown-4).

Investigation of mechanical properties of electrospun poly (vinyl chloride) polymer nanoengineered composite

Nanofiber membranes are extensively used in ultra- and micro-filtration purposes due to their high surface-to-volume ratio. However, nanofiber membranes do not have adequate strength to withstand forces acting on the filter surface, especially when using very low porosity membranes. In this study, PVC nanofiber mats and nanofiber composite membranes were fabricated through electrospinning and solvent casting technology. The membranes were characterized using scanning electron microscopy (SEM), porosimetry, and tensile strength tests. Analysis indicated that electrospun mats contain varying pore sizes (nano to micro) whose frequencies within the mat vary with fiber diameter. It was also established that mats fabricated from low solution concentration contain the largest percentage of pores. The mats’ tensile strength varied with fiber packing density, fiber assembly, and the density of fiber-to-fiber contact points. The tensile properties of the nanofiber composite membranes were found to be between those of the constituents and changed with change in the nanofiber layer thickness. The fabricated nanofiber composite membranes are intended for use in applications such as air ultra-filtration, acoustic filtration etc. The high porosity and small mesh pore size of electrospun nanofiber mats allow for removal of ultra-fine particles or microbes from contaminated air, water or other media.

Under pressure: electrochemically-mediated atom transfer radical polymerization of vinyl chloride

Electrochemically mediated ATRP (eATRP) of vinyl chloride (VC), a less activated monomer, was successfully achieved. It is the first report on eATRP of a gaseous monomer under pressure.

Polymerization of Vinyl Chloride at Ambient Temperature Using Macromolecular Design via the Interchange of Xanthate: Kinetic and Computational Studies

Reversible deactivation radical polymerization of vinyl chloride (VC) by methyl (ethoxycarbonothioyl)sulfanyl acetate (MEA)-mediated macromolecular design via the interchange of xanthate (MADIX) po...

The effects of initiators mixture on suspension polymerization of vinyl chloride and its comparison with other productivity-enhancing procedures

Molecular and morphological properties of poly(vinyl chloride) (PVC) grains produced by suspension polymerization of VCM in the presence of a mixture of fast, mild and slow initiators (named as Cok process) was experimentally investigated in a pilot-scale reactor. In contrast to nonisothermal and fast initiator dosage process, using initiators mixture has the smallest influence on molecular weight and polydispersity index compared to the control process. It is found that Cok-PVC grains have the lowest cold plasticizer absorption and porosity among productivity-enhancing processes. Scanning electron microscopy showed that the particles produced by Cok process are more regularly shaped, with a smoother surface compared with the control resin. All three productivity-enhancing techniques lead to an apparent quality enhancement, higher flowability and greater bulk density of final grains when compared with control resin grains. While both nonisothermal and fast initiator dosage polymerization process broaden the particle size distribution (PID) of final PVC grains, applying Cok process produces particles with the same PID as a control process. In comparison with nonisothermal trajectory and continuous fast initiator dosage system, the Cok polymerization process leads to the most delay of motionless conversions, fusion time and the formation of a three-dimensional skeleton of primary particles as well.

Controlled Radical Polymerization of Vinyl Chloride Mediated by Xanthene-9-Thione

The controlled radical polymerization (CRP) of vinyl chloride monomer (VCM), a low activity monomer with high radical reactivity, is still a true challenge. In this study, a novel CRP of VCM with high monomer conversion at 45 °C with xanthene-9-thione (XT) as mediator and bis(4-tert-butylcyclohexyl)peroxydicarbonate (TBCP) as initiator is achieved. The Mn of the produced poly(vinyl chloride) (PVC) increases slightly with increasing monomer conversion and could be mediated in the range from 6k to 12k by simply changing the molar ratio of TBCP/XT while the dispersity maintains around 2.0. The fidelity of XT dormant groups of PVC-XT is about 60–80% and depends on the ratio of TBCP/XT. With the as-prepared PVC-XT as macroinitiator, block copolymerizations of methyl methacrylate (MMA), n-butyl acrylate (BA), and styrene (St) are carried out and the PVC-b-PMMA, PVC-b-PBA, and PVC-b-PSt block copolymers have been synthesized successfully.

Morphology, mechanical property, and processing thermal stability of PVC/La‐OMMTs nanocomposites prepared via in situ intercalative polymerization

Poly(vinyl chloride) (PVC) nanocomposites were prepared via an in situ intercalative suspension polymerization of vinyl chloride with four organic carboxylic acid salts (montmorillonite [MMT] units) containing thermally stable lanthanum ions. The effects of different lanthanum organic montmorillonites (La‐OMMTs) on the particle features and molecular weight were investigated. The transmission electron microscopy data indicated the formation of partially exfoliated or intercalated PVC/La‐OMMTs nanocomposites. The effect of different functional groups on the mechanical properties and processing thermal stability of PVC/La‐OMMT nanocomposites were investigated. Tensile testing and two‐roll mill processing results showed that La‐OMMTs could enhance the dynamic thermal stability and mechanical properties versus PVC pure resin and PVC/I.30P nanocomposites (composed of PVC and I.30P). This suggested that the double bond and amidogen group in La‐OMMTs could promote the dispersion of La‐OMMTs in the PVC matrix and also improve the adhesion between the La‐OMMTs and PVC matrix. The results have potential value in the industrial development of PVC/La‐OMMTs nanocomposites. J. VINYL ADDIT. TECHNOL., 26:97–108, 2020. © 2019 Society of Plastics Engineers