PVC Waste Research Articles

Waste polyvinyl chloride‐modified bitumen

AbstractPolyvinyl chloride (PVC) pipe wastes have been employed as a soft filler up to a level of 11 wt % in making bituminous products for paving applications. The PVC wastes were homogenously mixed with bitumen in the molten state. The viscoelastic properties of the bitumen blends such as storage modulus, loss modulus, and dynamic viscosity were studied and compared with those of neat bitumen. These properties were studied using an ARES‐Rheometer (Rheometric Scientific, Co.) under nitrogen atmosphere. The results indicate that the incorporation of the waste PVC into bitumen enhances the dynamic mechanical moduli and viscosity of the bitumen. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1501–1505, 2006

Photocatalytic degradation of flexible PVC/TiO 2 nanohybrid as an eco-friendly alternative to the current waste landfill and dioxin-emitting incineration of post-use PVC

Photo-degradable poly(vinyl chloride) (PVC)/titanium dioxide (TiO 2) nanohybrid has been investigated to be utilized as an eco-friendly alternative strategy to the current waste landfill and toxic byproduct-emitting incineration of PVC wastes. Thus, the present study suggests a novel idea related to preparing the photocatalytically degradable nanohybrid through TiO 2 nanoparticle-integrated hyperbranched poly(ε-caprolactone) (HPCL–TiO 2). The main aim of this study is to find a solution to the unresolved problem in the conventional PVC/TiO 2 composites related to the poor dispersion of the nanoparticles in PVC polymer. First, TiO 2 nanoparticles are prepared by a sol–gel process, and the size of the particle is about 5–10 nm in diameter as measured by using a transmission electron microscopy (TEM) and dynamic light scattering (DLS). The hyperbranched poly(ε-caprolactone) (HPCL) with numerous COOH groups and good miscibility with PVC as a binder for TiO 2 nanoparticles is prepared from moisture-sensitive catalyst-free polymerization of 2,2-bis[ω-hydroxy oligo(ε-caprolactone)methyl]propionic acids followed by modification reaction using pyridinium dichloromate (PDC), then characterized with 1H NMR and 13C NMR analyses. The integration of TiO 2 nanoparticles onto HPCL is carried out by a dip-coating method based on the spontaneous self-assembly between TiO 2 nanoparticles and HPCL, and the loading amount of the nanoparticles in the HPCL–TiO 2 is determined to be ca. 3.3 wt% by X-ray photoelectron spectroscopy (XPS). Then, the HPCL–TiO 2 is blended with PVC by solution blending in THF as solvent, and the resulting dispersibility of TiO 2 nanoparticle in PVC is characterized by field emission scanning electron microscopy (FESEM) equipped with energy dispersive spectrometry (EDS), which exhibits the TiO 2 nanoparticles are well-dispersed in PVC matrix, while some agglomerates are observed in the PVC/TiO 2 sample prepared from TiO 2 nanoparticle itself. The photocatalytic degradation of the samples are examined and verified from the change of surface morphology, chemical structure, molecular weight, and molecular-level structure after UV irradiation through field-emission scanning electron microscopy (FESEM), UV–visible spectroscopy, gel permeation chromatography (GPC), and positron annihilation lifetime spectroscopy (PALS). The remarkable photocatalytic degradation is observed in the PVC/HPCL–TiO 2, and the structural change accompanied by the degradation of the irradiated sample can clearly explained.

Carbonization of waste PVC to develop porous carbon material without further activation

Efficient removal of chlorine from PVC achieved by two-stage heat-treatment (280 and 410 °C) provided chlorine-free isotropic pitch containing additive. The pitch was stabilized and carbonized into porous carbons with surface areas of ∼300 m 2/g. Resultant porous carbons showed three pore structures of supermicropore, micropore and mesopore. The generation of CO 2 from the decomposition of the CaCO 3 additive in waste PVC is responsible for the development of porous structures. The surface area of the carbonized product increased after the removal of CaO.

7-9.触媒を用いた廃PVCからの水素製造プロセスの開発((3)廃棄物転換燃料,Session 7 環境対策・リサイクル)

7-9.触媒を用いた廃PVCからの水素製造プロセスの開発((3)廃棄物転換燃料,Session 7 環境対策・リサイクル)

廃プラスチック系床材の再資源化技術の開発(材料施工)

The first purpose of this paper is the development of recycled PVC sheets which is applied as floorcoverings, and second purpose is development of fiber reinforced plastic sheets which containing fiber of the waste carpet-tiles. In this research, we deal with three kinds of waste PVC floorcoverings (Homogenias-tail, PVC flooring sheets, and carpet-tile) as the recycling raw materials. Tension tests and dimensional stability (bathed in hot air at 80℃, 6hrs.) tests on recycled PVC sheets specimen were performed. As a result, the influence of proportioning and fiber mixing rate on the quality of the recycled PVC sheets was clarified.

Basic study on treatment of waste polyvinyl chloride plastics by hydrothermal decomposition in subcritical and supercritical regions

We are developing a process for treating waste plastics in an environmentally friendly way. The increased awareness of possible problems caused by waste PVC plastics is leading to a need to develop a reliable technique for treating them in a safe and environmentally friendly way, that is, in a way that does not lead to the release of chlorinated organic compounds. We focused on using water vapor at sublimation pressure and subcritical and supercritical water as solvents for treatment. We found that the chlorine in PVC dissolved in water as hydrochloric acid, and no harmful chlorinated organic compounds were observed in the liquid and gas fractions after treatment at 300 °C. Between 250 and 350 °C, this technique produced polyene as a residual solid, and low-molecular weight aromatic and aliphatic compounds in the liquid and gas fractions. Further decomposition at over 350 °C in supercritical water produced acetone, phenol, benzene, benzene derivatives, and aliphatic alkane and alkene in the liquid and gas fractions. The combustion enthalpy of the residual solid was 9270 kcal/kg, which is in the same range as the values for coal and coke, so it has good potential as a fuel ingredient. This technique is promising for establishing a non-toxic and almost perfectly closed system for the treatment of waste PVC in a sustainable society.

Poly(vinyl chloride) on the way from the 19th century to the 21st century

AbstractDespite all the technical and economic problems and the public discussions on the environmental dangers and hazards of chlorine chemistry, poly(vinyl chloride) (PVC) is the second most produced plastic (with a worldwide capacity of about 31 million tons), placing after polyolefins and before styrene polymers. Presently, PVC production worldwide is growing at a rate of more than 4% per year. The application of PVC was first described in a patent in 1913, but only after 1930 did a sustained interest in PVC arise in several industrial laboratories. The most remarkable milestones in PVC history and their importance to the development of macromolecular chemistry are briefly described, and some present PVC research and industrial applications, with respect to polymerization, stabilization, bulk property modification, and chemical and material recycling of PVC waste, are discussed. Some actual selected topics include the emulsion polymerization of vinyl chloride with polymeric surfactants and controlled free‐radical polymerization with nitroxyls, whereas ionic and metal organic initiators have not found any technical applications. Chemical reactions offer many possibilities for the modification of PVC, but they have been not used on a technical scale yet. Much work has been done on stabilization with nontoxic or metal‐free systems. The bulk properties of PVC can be influenced by impact modification through the addition of graft copolymers or by blending with other polymers. Also presented are some problems and recent developments in PVC recycling. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 578–586, 2004

Chlorine Gas Recovery from Waste PVC through CaCl2Reaction between Molten CaCl2 and Oxygen Gas

Chlorine gas evolution was investigated by bubbling O2 gas into molten CaCl2 at temperatures higher than 1173 K, although a thermodynamic analysis shows almost no progress of the reaction 2CaCl2 + ...

El rastro del Cadmio

El cadmio es un metal pesado que se encuentra en el aire viciado, en algunos vertidos industriales, incluidas las aguas residuales, en el reciclaje de desechos de PVC y en la incineración de la basura. También se origina en la producción de plomo, zinc, en la quema de combustibles fósiles (petróleo y derivados) y en el empleo de fertilizantes fosfatados y plaguicidas, muy comunes en nuestra agricultura. Es un elemento tóxico para todos los seres vivos.Pero la industria del plástico sigue insistiendo en la inocuidad de sus productos. Aún así, el círculo de las evidencias se cierra cada vez más. Hace poco un grupo de expertos del Ministerio del Medio Ambiente de España advirtió del peligro de hornear o calentar alimentos envasados en frascos de PVC, debido a su contenido de sustancias tóxicas, siendo una de las más peligrosas un metal blanco no ferroso llamado cadmio, un elemento que ha llamado la atención por su poder de asimilación en el organismo, su mortal potencial cancerígeno y por ser causa de terribles anomalías congénitas, como ha quedado demostrado en diversos estudios científicos.

PVC waste utilization in Japan is ahead of the average

PVC waste utilization in Japan is ahead of the average

Waste PVC won’t just be exported, says EuPR

Waste PVC won’t just be exported, says EuPR

Fate of PVC polymer, plasticizers, and stabilizers in landfilled waste

AbstractEnd‐of‐life PVC products are predominantly disposed of with construction waste or with municipal solid waste in sanitary landfills. This waste management option is currently subject to debate because of environmental issues. A material and substance flow analysis was conducted to estimate the quantitative relevance of PVC products and their constituents in municipal solid waste. Landfill simulation assays demonstrated the long‐term behavior of PVC products and the fate of additives under landfill conditions. The PVC polymer was found to be stable. A loss of plasticizers may occur in case of insufficient compatibility with the PVC compound coupled with microbial consumption at the PVC product surface. Losses of stabilizers are generally restricted to transient leaching from the product surface. Plasticized products show a somewhat stronger inclination to release their stabilizers. The findings indicated that additional measures specifically directed at post‐consumer PVC waste in landfills are not necessary.

Fundamental Researches on Utilization of The Waste PVC Films for Agriculture

The burning-up of scrapped materials in the outdoors is prohibited clearly with the processing standard. We must implement the light way of the load to keep environment of processing, and must carry out clearly the entrusting procedure. We investigated about how the wasted PVC film was processed. The investigation objects is the processing measure of the wasted PVC film for agriculture, and it becomes social needs.The wasted PVC film for the agriculture is softened and becomes compressed clod. The middle-processing trader condenses the wasted PVC film for agriculture collected. We examined about the utilization of the condensed one.We did CBR test about the compressed clod. Combining the scrap of concrete with carbide stably processed it.

Pyrolysis kinetics of waste PVC pipe

The pyrolysis kinetics of waste PVC pipe was investigated with a thermal gravimetric analysis system at heating rates of 5, 10, and 30°C/min in a nitrogen atmosphere. Freeman-Carroll method was employed to evaluate kinetic parameters. Two dominant peaks were observed on derivative gravimetric curves, hypothetically suggesting a two-stage apparent reaction model. The first-stage reaction was likely to be represented by stoichiometric reaction to yield volatiles (mainly HCl) and intermediates. The second-stage reaction might be described by thermal degradation of intermediates competitively into gas, liquid, and solid by-products. Quasi-isothermal operations were introduced to verify the reaction types of the first and second reaction. The generation reaction of intermediates achieved at lower temperatures was carried out independently with their decomposition reaction at higher temperatures. The effects of additives on the pyrolysis kinetics of waste PVC pipe seem to be significant, especially on the first-stage reaction. The first-stage reaction was retarded. A merged peak at low temperatures was observed on the derivative thermogravimetry (DTG) curve instead of two peaks usually observed for that of pure PVC resin. The first peak on the DTG curve of pure PVC resin may shift more, resulting in the complete overlap of two peaks. The quantity of evolved HCl was likely to decrease because of interaction of metal components of stabilizers with either HCl or active chlorine atom or both. The final residual fraction increased as a result of pyrolysis of organic forms of additives to yield extra char. On the other hand, the second-stage reaction kinetics demonstrates a similar pattern to that of pure PVC resin, implying that the effects of additives may be less significant in comparison with that at the first-stage reaction.

00/03528 A new technology for treatment of PVC waste

00/03528 A new technology for treatment of PVC waste

00/02783 Co-pyrolysis of waste PVC with coal

00/02783 Co-pyrolysis of waste PVC with coal

Design of a process for steam gasification of PVC waste

One possibility for recycling of PVC waste is steam gasification in a bubbling fluidized bed reactor. The main products are syngas , employable for energy recovery and HCl that can be reused for PVC production in an oxychlorination plant. In this study the technical and economical feasibility of this process is investigated based on experimental data and the implementation of proven technology where possible. The design capacity is 50 kton waste/year. Mass and energy balances were determined by the simulation software package Aspen Plus. Equipment costs of the simulated equipment are estimated and the gate fee of the PVC waste is calculated with a discounted cash flow analysis. The produced syngas proves to have a heating value of 8.6 MJ/Nm 3 . Half of the chlorine, present in PVC waste, can be regained as pure HCl gas. The rest leaves the process as CaCl 2 waste due to the presence of lime, added as a filler material to many PVC compounds. The total investment costs are 10 million EUR. The gate fee, needed to obtain an internal rate of return of 15%, is established at about 67 EUR. The gate fee proves to be very sensitive for variation in the investment costs and is strongly affected by the costs of CaCl 2 disposal.

A new technology for treatment of PVC waste

This paper presents a new environmentally sustainable technology for chemical recycling of PVC waste. The new technology transforms PVC waste into completely new chemical products/raw materials. The process is based on a combined thermal and chemical degradation of PVC in a reactor. In the reactor, the chlorine from the PVC reacts with fillers producing calcium chloride. The metal stabilisers (lead, cadmium, zinc and/or barium) are converted to metal chlorides. Exploiting the influence of pH, temperature, liquid to solid ratio and comminution on the metal solubility, metals and calcium chloride are sequentially extracted from the reaction product. This occurs in a downstream multi-stage extraction-filtration procedure. The products from the process are: (1) calcium chloride, which satisfies the specifications as thaw-salt, (2) lead (metal) product, which may be further purified and re-used, (3) coke and (4) organic condensate, which may be used as energy resources for the process. This paper presents the basis of the technology in terms of reaction and separation principles, selected process equipment and process design. Further the economy of the process, environmental issues and product purities/applications are addressed.

Thermal Degradation of Plastics Compounded With Petroleum-derived Bitumens

Thermal analysis-based preparation of blends of selected polymer wastes with pyrolysis oil was studied and results are presented. Selected thermomechanical methods were evaluated as regards the determination of property data of the resulting products. When pyrolysis oil was used in amounts ≥5mass%, homogeneous blends could be prepared with PE and PET wastes; the blends were found to be processible by compression molding or injection molding. Blends prepared from waste PVC and pyrolysis oil were brittle and hard. The following properties could be determinated for the thermal products: ring-and-ball softening point, Vicat softening point, melt flow index, and impact strength.

Long term behaviour of poly(vinyl chloride) products under soil buried and landfill conditions

The long term performance of poly(vinyl chloride) (PVC) products has been investigated in laboratory scale landfill simulation assays. Leachate and gas were monitored and PVC samples were inspected. No degradation of the PVC polymer was observed. Plasticised PVC products showed a certain loss of additives. In addition, leachate samples from actual landfill sites were analysed for phthalates and organotin compounds. A preliminary assessment of the environmental impact indicates that there is no significant contribution of PVC waste to concentrations of heavy metals in landfills, and the presence of phthalates and organotin compounds in the leachate is not expected to constitute a risk to the aquatic environment.