PVC Composites Research Articles

Cotton Weaving Waste Incorporation in PVC Composites

The largest amount of solid waste from the textile industries is mainly derived from fabric manufacturing until the cutting stage: hard fibers (spinning waste), beaming and soft fibers (weaving yarn waste), and off-cuts (cutting process). This research aimed to (i) conduct an exploratory interview with a large Brazilian cotton textile manufacturer to identify its main solid waste and corresponding destinations; and (ii) produce and evaluate PVC composites reinforced with cotton textile residues from the weaving process. Cotton fibrous reinforcements in the proportion of 2.5% (w/w) presented the best results of tensile strength and elongation concerning the others. Briquette residue (2.5%) had better dispersion in the matrix and slightly higher tensile strength when compared to other residues. The composites presented different visual aspects, and their use in fashion products with sustainable appeal could be a viable alternative. Therefore, additional tests should be performed to ensure the appropriate mechanical properties for applications in this and other areas.

Superior flame retardancy and smoke suppression of poly (vinyl chloride) composites with iron/tin‐doped bismuth oxychloride

AbstractDoping is a simple and effective method to change material properties. In this work, in order to improve the flame retardant performance of bismuth oxychloride (BiOCl) nanosheets in poly (vinyl chloride) (PVC), for the first time, iron and tin ions were doped into BiOCl (Fe‐BiOCl and Sn‐BiOCl) via a doping approach, respectively. X‐ray diffraction and morphology characterization confirmed that the Fe and Sn ions were doped into the BiOCl lattices, respectively. After doping, PVC composites obtained superior flame retardancy and smoke suppression. With the adding amount of 3 wt% Fe‐BiOCl and Sn‐BiOCl, the UL‐94 test rating of the PVC composites reached V‐0, and the peak of heat release rate reduced by 38% and 34%, total smoke production decreased by 55% and 42%, respectively, compared to neat PVC. Thermogravimetric and Thermogravimetric‐Fourier Transform Infrared results showed that Fe or Sn doping could further reduce organic volatiles in the gas‐phase and improve char residual in the condensed phase, both of which contribute to reducing fire hazards. Tensile properties and tensile modulus of PVC composites increased. In short, it is an economically effective approach targeting to improve the comprehensive properties of PVC through doping Fe or Sn into BiOCl.

Modeling the formulation of the PVC cable composition

Increasing the fire-retardant characteristics of polymeric cable materials has attracted the close attention of experts all over the world for many years, since fires are often associated with the ignition of cable products, followed by the spread of fire through cable communications. In this regard, the development of new modern formulations of fireproof compositions with improved performance properties is especially relevant for the production of PVC cable composites. The article describes the production of a new phosphorus-containing flame retardant phenyldixylol phosphate and investigated its physicochemical properties. The new flame retardant was tested in an industrial formulation of a PVC cable composition using dibutoxyethyl adipate as a plasticizer. Using the methods of correlation-regression analysis and optimization, the optimal ratio of the resulting additive and tricresyl phosphate was selected, which provides the best technological and operational parameters of the PVC composite.

Modeling the kinetic regularities of the preparation of dibutoxyethyl adipates

Additives are important components of PVC composites, providing polymer modification and retention of its properties throughout the entire period of operation. The development and application of environmentally friendly adipate plasticizers is urgent. The article presents the results of kinetic studies of the esterification of adipic acid with ethoxylated n-butanol of varying degrees of ethoxylation. The effect of various catalysts on the yield of the target ester and the degree of ethoxylation on the rate of the esterification reaction was studied. A mathematical model of the kinetics of the process of obtaining dibutoxyethyl adipates of various degrees of ethoxylation has been developed, which makes it possible to predict the technological indicators of the efficiency of the acid catalyst and the effect of the degree of ethoxylation of the alcohol used. Keywords: adipate plasticizer; kinetics; mathematical model; polyvinyl chloride; prediction; esterification.

Study of the Rheological Properties of PVC Composites Plasticized with Butoxyethyl Adipates

Polyvinyl chloride compositions are widely used to obtain various types of products. In the composition of the PVC composite, one of the main ingredients is a plasticizer, the introduction of which makes it possible to vary the characteristics of the obtained polymeric materials and products and significantly expand the range of their application. Manufacturability in the processing of polyvinyl chloride compositions serves as an important criterion for the suitability and economic efficiency of the developed plasticizer. In the modern world, the high quality of products is directly related to their environmental safety. In this regard, the work describes the production of environmentally friendly plasticizers based on adipic acid and ethoxylated butanol. Their physicochemical indicators have been investigated. The effect of the obtained additives on the rheology of PVC composites has been studied. The values of the flow characteristics of the melts of the developed PVC compositions plasticized with butyl butoxyethyl adipate and decyl butoxyethyl adipate were estimated. It was shown that the fluidity of melts, in comparison with compounds of a similar composition containing industrial dioctyl phthalate, is characterized by even slightly higher values.

Experimental and computational study of thermal behavior of PVC composites based on modified eggshell biofiller for UPVC product

Experimental and computational study of thermal behavior of PVC composites based on modified eggshell biofiller for UPVC product

Obtaining environmentally friendly cable PVC composites

Polyvinyl chloride compositions are very popular in the cable industry. The range of domestic fireproof cable PVC plastics is limited to several manufactured brands that were developed more than 30 years ago and do not meet modern international standards. The creation of new environmentally friendly formulations of fireproof cable plastics with improved operational properties is an urgent task. This paper describes a method of synthesizing a novel ester compound of phenyl dixylenyl phosphate. The conditions for its production with maximum yield are selected. Physicochemical properties of the new flame retardant are studied. A non-toxic biodegradable PVC composition based on a plasticizer of dibutoxyethyl adipate and a novel flame retardant is formulated. The results of tests of the developed PVC-composite on the main indicators for cable products of the I40-13 brand are presented.

Effect of gamma dose rate in the crosslinking of PVC composites used for radiation protection in radiology

Flexible PVC composites loaded with various levels of tantalum carbide (TaC) were gamma irradiated at two different dose rates and their effect on crosslinking level, thermal stability and mechanical properties evaluated. The shielding properties of composites against X-Rays at radiodiagnosis energies were also evaluated. Gel percentage results indicate a relatively stable crosslinking level after irradiation, only some reduction was observed for highly loaded composite treated at a low dose rate, although thermal stability observed by TGA was maintained. TaC particles were properly dispersed within the PVC material, as seen by SEM and toughness increased when both E' and E'' Moduli were enhanced after irradiation; even Tg, followed by Tanδ DMA curves, increased noticeably after treatment and for the higher TaC loaded composites, particularly when treated at low dose rate irradiation. Density measurements indicated lighter and manageable materials with respect to traditional shielding items. The shielding properties for composites, evaluated in a clinical X-Ray apparatus, in the 50–129 kV interval, show mass attenuation coefficients close to the ones reported for lead, even higher for 50% TaC loaded composite and a very competitive half-value layer (HVL) for all of them.

Synergistic effect of talc/calcined kaolin binary fillers on rigid PVC: Improved properties of PVC composites

AbstractThis study aims to develop poly(vinyl chloride) (PVC) composites prepared by melt mixing by using a combination of talc and calcined kaolin as filler in order to improve the disadvantages of rigid PVC, which is widely used in industry, such as poor mechanical properties and low thermal stability. In addition, PVC/talc and PVC/calcined kaolin composites were also examined for comparison. The calcined kaolin is modified with urea to increase the surface area (chemical treatment), while the surface of both fillers is coated with stearic acid for good compatibility with PVC (mechanical treatment). Scanning electron microscopy micrographs showed homogeneous distribution of mechanically processed fillers. Attenuated total reflectance–Fourier‐transform infrared spectroscopy analysis revealed successful coating of the fillers with stearic acid. Also, new bands were detected in the spectrum of urea‐treated calcined kaolin, showing an effective chemical treatment. It has been observed that the treatment of fillers improves the mechanical properties of PVC. Thermogravimetric results showed that delaminated calcined kaolin increased the thermal stability of PVC composites. The results of this study proved that binary filler composites combine good properties of both (synergistic effect) and good filler dispersion can be obtained by using stearic acid and urea.

Ecotoxicity of the Adipate Plasticizers: Influence of the Structure of the Alcohol Substituent.

A significant increase in the production of plastic materials and the expansion of their areas of application contributed to the accumulation of a large amount of waste of polymeric materials. Most of the polymer composition is made up of plasticizers. Phthalate plasticizers have been recognized as potentially hazardous to humans and the environment due to the long period of their biodegradation and the formation of persistent toxic metabolites. It is known that the industrial plasticizer dioctyl adipate is characterized by reduced toxicity and a short biodegradation period. The paper describes the synthesis of a number of new asymmetric esters based on adipic acid and ethoxylated butanol by azeotropic esterification. The receipt of the products was confirmed by IR spectra. The physicochemical properties of the synthesized compounds were investigated. The glass transition temperatures of PVC composites plasticized with alkyl butoxyethyl adipates were determined using DSC analysis. The ecological safety of esters was assessed by the phytotesting method. Samples of adipates were tested for fungal resistance, and the process of their biodegradation in soil was also studied. It is shown that the synthesized esters have good plasticizing properties and are environmentally safe. When utilized under natural conditions, they can serve as a potential source of carbon for soil microorganisms and do not form stable toxic metabolites; therefore, they are not able to accumulate in nature; when the plasticizers under study are disposed of in the soil, toxic substances do not enter.

Experimental investigation on compression strength of EPOXY/PVC blend with different fibre glass reinforcements

Polymer matrix composites with different fibre glass reinforcements like wool, woven ring and mesh has been prepared through hand layup method for the experimental investigation on compression strength and weight evaluation. EPOXY/PVC blend has been used as matrix material with different weight percentages of PVC such as 5%, 15% and 25%. The prepared specimen has been subjected to heat treatment in a oven for different timing such as 15, 30 and 45 min. The present study considers the percentage of PVC, fibre glass type and heating time as input factors to observe their effect over weight and compression strength of the specimen through Taguchi’s L27 Orthogonal array. The statistical analysis of experimental results through signal to noise ratio method and ANOVA reveals that the type of fibre used for making the specimen has more influence over both the output parameters. The heat treatment provided to the specimen and the percentage of PVC has no significant effect and the residual error in analysis is around 10%.The investigation carried out reveals that 5% PVC composition with woven rings reinforcement material has shown the maximum compression strength and highest specimen weight and the changes in matrix material combinations with different PVC compositions, fiber glass with increased or decreased thickness may be considered as the future directions of the current study.

Kinetic and thermodynamic studies of polyvinyl chloride composite of manganese oxide nanosheets for the efficient removal of dye from water

Abstract Manganese oxide nanosheets and manganese oxide composite with polyvinyl chloride (MnO2-PVC) were synthesized by the oxidation method for the efficient removal of Congo red (CR). The Fourier transform infrared spectroscopy, X-ray diffraction, energy dispersive X-ray, surface area (SA), point of zero charge (PZC) and thermogravimetric analysis were performed to verify the newly synthesized adsorbents. After functionalizing the surface of MnO2 nanosheets with PVC, the PZC and SA were amplified from 4.10 and 214 m2g−1 to 5.01 and 226 m2g−1, respectively. The batch adsorption results showed that the removal capacity of CR on both the adsorbents decreased with the increase of pH and time, but increased with the increase of adsorbent dosage. However, due to the high stability, porosity and greater surface area, the PVC composite of MnO2 was found to exhibit 15 times greater CR removal efficiency than its parent MnO2. Furthermore, the thermodynamic parameters specified that CR adsorption onto both the adsorbents was exothermic, spontaneous and film diffusion accompanied by the intraparticle diffusion is the rate controlling step. These results validate that MnO2 composite with PVC is a useful, eco-friendly, competent candidate for dye removal from wastewater.

A facile approach to prepare anhydrous MgCO3 and its effect on the mechanical and flame retardant properties of PVC composites

AbstractAnhydrous MgCO3 is considered a promising inorganic filler because of its many outstanding properties. In this study, a facile approach was developed to prepare anhydrous MgCO3 using urea as CO2 source. MgCO3 with cube‐like morphology (MC‐cube) was prepared and then modified with β‐cyclodextrin (CD) (CD@MC‐cube) in order to improve its interfacial adhesion with PVC matrix. The results indicate that the incorporation of MgCO3 can not only reinforce and toughen PVC composites, but it can also enhance their thermal stability and flame retardancy. Specifically, the impact strength of CD@MC‐cube/PVC composite with 4 wt% of CD@MC‐cube is increased by 92.5%, and the total smoke production and the total heat release of CD@MC‐cube/PVC composite with 12 wt% of CD@MC‐cube are decreased by 38.8% and 51.3% compared with that of PVC matrix, respectively.

Designing of Green Plasticizers and Assessment of the Effectiveness of Their Use.

The growing anthropogenic load on the lithosphere is currently characterized by the alienation of huge areas for solid domestic waste. One of the most common pollutants is traditional plastics with a degradation period of over 100 years. In connection with the increasing environmental requirements, polymer materials, along with a high set of technological and operational parameters, must be environmentally friendly and biodegradable. The development of polymer composite materials that undergo accelerated physicochemical and biological changes in the natural environment due to the introduction of biodegradable additives is one of the potential methods for processing synthetic materials and ensures the release of significant areas of fertile soils and lands from the steadily increasing amount of polymer waste. The use of adipic acid esters as PVC plasticizers contributes to the production of biodegradable composites. The article describes a method for obtaining new esters of adipic acid, presents the results of studying their properties for practical use in PVC composites, and assesses the economic efficiency of preventing damage to the environment when using them.

Effects of ZnAl layered double hydroxide and benzimidazole derivative on the dechlorination of poly(vinyl chloride)

Layered double hydroxides (LDHs) that are generally used as thermal stabilizers of poly(vinyl chloride) (PVC) can also have catalytic effects on the dechlorination of PVC. In this study, benzimidazole derivative (OBPB) modified ZnAl-LDH (OBPB@ZLDH) was synthesized and incorporated into PVC, and the effects of OBPB@ZLDH and the physical blend of OBPB and ZLDH (OBPB/ZLDH) on the dechlorination of PVC were investigated by Congo red test and discoloration test. The results indicated that OBPB/ZLDH could improve the thermal stability of PVC. The composition and chemical structure of PVC composites after discoloration test were studied by energy dispersive X-ray spectroscopy and attenuated total internal reflectance-infrared spectroscopy. The results revealed that the products derived from the reaction between HCl released in the thermal degradation of PVC and OBPB/ZLDH could accelerate the dechlorination and oxidization of PVC at low temperature. Therefore, it has potential applications in the dechlorination of PVC to prepare hydrochars for use as alternative fuels at low temperature.

Synthesis of poly(vinyl chloride)-co-poly(acrylic acid) by precipitation polymerization and its usage as CaCO3 modifier in rigid PVC composites

Incorporating carboxyl group into the poly(vinyl chloride) (PVC) resin can endow PVC with reactivity in some applications. In this work, poly(vinyl chloride)-co-poly(acrylic acid) random copolymer (PVCA) with low average number molecular weight (M n, ∼10 k) is synthesized by precipitation polymerization. By tuning acrylic acid dropping rate, the PVCA copolymer with much more uniform copolymer composition is obtained in comparison to all monomer-in process. Subsequently, the PVCA is utilized as a novel polymer modifier for the surface treatment of CaCO3 particles and its effect on the mechanical properties of obtained rigid PVC composites are evaluated systematically. As a result, the PVAC modified CaCO3 particles exhibit uniform dispersibility and excellent compatibility in PVC matrix. Additionally, the thermal stability is improved significantly owing to the calcium ions on the surface of CaCO3 particles, which scavenge the hydrogen chloride and retard the autocatalytic dehydrochlorination process. Impressively, it also has an enhancement both in tensile strength (ca. 46.4 MPa, and 119.8% elongation at break) and in impact strength (2.7 kJ m−2) in comparison to those modified by commercialized agents such as stearic acid and titanate ester. This work provides valuable insights for the preparation of vinyl chloride copolymers and opens a new application.

THERMO- AND LIGHT STABILIZING ACTIVITY OF VINYLOXYCLOPROPANE ADDUCTS WITH THIOLS IN THE COMPOSITIONS BASED ON PVC

During exploitation of PVC products, the negative impact of high temperatures and light, and also the destructive influence of various microorganisms, leads to the deterioration of physical-mechanical properties and change of products painting. For prevention of the dehydrochlorination process of PVC, it is necessary to use the effective complex stabilizers, including biostabilizers, differing with their high processability and simultaneously possessing biocidal properties. 
 In this work the results of investigations of influence of the synthesized sulphur-containing epoxycyclopropanes as stabilizing additives for prevention of the dehydrochlorination process of the compositions based on plasticized PVC have been presented. The influence of these compounds as co-stabilizers in the composition of complex stabilizers – stearates Ca (CaSt2) and Zn (ZnSt2) on thermo- and light stability of PVCcompositions and also on their physical-mechanical and exploitation indices has been studied. It has been established the synthesized epoxy- and cyclopropane-containing mono- and disulphides jointly with stearic acid salts form the synergic mixtures, which can improve the physical-mechanical properties of PVC compositions, their thermal and light stability.

ADDUCTS OF SUBSTITUTED VINYLOXYCYCLOPRFOPANES WITH THIOLS AS THERMOSTABILIZERS OF PVC

The compositions on the basis of PVC, containing dioctyl phthalate as a plasticizer, complex thermal stabilizers – calcium and zinc stearates and adducts of thiophenol and ethanedithiol with gemdiglycidyloxymethylsubstituted cyclopropylvinyl ether as co-stabilizers and biocidal additives were developed. Thermal properties of the developed compositions were investigated and the influence of the synthesized sulfur-containing adducts on the thermal stability and color change of the compositions studied. The tests were carried out to reveal the antifungal activity of adducts in the structure of PVC compositions. It found that the chemical structure of adducts after introduction into the structure of compositions was not essentially changed. The compositions with the participation of adducts as co-stabilizers acquired improved indices on thermal stability, color stability and antifungal activity.

Gamma attenuation through nano lead - nano copper PVC composites

Polymer composites of polyvinyl chloride, PVC, were loaded up with micro and nano PbO/CuO particles. The added percentage of each by mass was 10 wt.%, 20 wt.%, 30 wt.%, and 40 wt.%, plus 40 wt.% of mixed composite (20 wt.% CuO + 20 wt.% PbO). The mass and linear attenuation coefficients of the investigated composites were measured as a function of gamma-ray energies going from 59.53 keV to 1408.01 keV utilizing standard radioactive point sources. To confirm the validity of these results the attenuation coefficients for bulk composites (PVC + PbO and PVC + CuO) were calculated by using the XCOM software. The results were in good agreement with the values obtained from the experimental work. By comparing the attenuation coefficients of the different composites it was found that those loaded with either nano PbO or CuO have higher values than those loaded with bulk sizes with the same percentage. Also, samples loaded with nano PbO have the highest attenuation coefficients even by comparing them with (20 wt.% CuO + 20 wt.% PbO), especially in the energy region below 1 MeV, but for greater energies, the values become very closed. The investigation of the mechanical properties of such composites due to the injection of bulk and nano metals reveals that tensile strength and Young's modulus of PVC nanocomposite sheets were notably increased with the increasing concentration of CuO and PbO nanoparticles. The CuO nanocomposite showed the highest values of flexural strength, toughness, and tensile strength among all the fabricated nanocomposite sheets.

Synthesis of zinc hydroxystannate/reduced graphene oxide composites using chitosan to improve poly(vinyl chloride) performance

Chitosan-modified zinc hydroxystannate (ZHS-CS) was synthesized using the cations of the biomaterial chitosan (CS) and ion replacement strategy. A ZHS-CS and reduced graphene oxide (rGO) hybrid flame retardant (ZHS-CS/rGO) was synthesized for use in flexible poly (vinyl chloride) (PVC). Scanning electron microscopy images indicated that ZHS-CS and rGO were evenly dispersed in ZHS-CS/rGO without agglomeration. Fourier transform infrared spectroscopy results showed that rGO was fully reduced. The flame-retardant and mechanical properties of PVC composites were investigated using the limiting oxygen index (LOI), a cone calorimeter, and mechanical equipment. By replacing one-fifth of the zinc ions in ZHS by chitosan cations to obtain Sn-4Zn-1CS/rGO, the ZHS-CS/rGO was found to improve PVC composite performance. The total heat release and total smoke release of PVC/Sn-4Zn-1CS/rGO were reduced by 24.2 and 40.0 %, respectively, from those of pure PVC.