Polyvinyl chlorides

Polyvinyl chloride is one of the cheapest plastics in use today. It is prepared by the polymerization of vinyl chloride (VCM) (CH2=CHC1, B.P.—14°C) as a suspension or emulsion in a pressure reactor. The polymer is unstable at high temperamres and liberates HCl at T 200°C. It can be injection molded or formed into a hard and brittle material. It can be readily softened by the addition of plasticizers such as diethylhexylphthalate to the extent of 30%. Plasticized PVC is used as an upholstery substitute for leather. Since the plasticizer is volatile to a small extent, it slowly leaves the vinyl which eventually becomes hard, brittle, and then cracks. This can be restored by replacing the plasticizer by repeated conditioning of the vinyl surface. 

Polyvinyl chloride (PVC) is one of the most widely used thermoplastics. It can be extruded into sheets and film and blow molded into bottles. It is used in many common items such as garden hoses, shower curtains, irrigation pipes, and paint formulations. 

PVC can be prepolymerized in bulk to approximately 7-8% conversion. It is then transferred to an autoclave where the particles are polymerized to a solid powder. Most vinyl chloride, however, is polymerized 

Fill temperature, max. °C Tensile strength, psi Water absorption, 24 hr., % Elongation, % 

Melting point, °C Thermal expansion, 10 in./in. Specific volume, cm /lb 

Polyvinyl chloride can also be produced in emulsion. Water is used as the emulsion medium. The particle size of the polymer is controlled using the proper conditions and emulsifier. Polymers produced by free radical initiators are highly branched with low crystallinity. 

Polyvinyl chloride furnishes a good example of how the infrared spectrum can provide confirmatory evidence on the nature of the isomeric structure. 

Chemical evidence [Marvel, Sample, and Roy (726)] as well as recent infrared studies [Hodgkins (75)] have established that PVC has mainly a 

Early x-ray work [Fuller (64)] had indicated that the chain configuration might be syndiotactic, but since this depended primarily on interpretation of the 5.1 A fiber axis repeat, the remainder of the pattern not being detailed enough to test this hypothesis adequately, this structure could not be considered to be firmly established. A detailed analysis 

The spectrum of an oriented specimen of PVC is shown in Fig. 9. This specimen is a typical low-crystallinity PVC. Higher crystallinity specimens, prepared by polymerization at low temperatures [Grisenth-waite and Hunter 68) Krimm, Berens, Folt, and Shipman 105)  

Shimanouchi, Tsuchiya, and Mizushima (196)J and by irradiation of urea-canal complexes [Krimm, Berens, Folt, and Shipman (106) Shimanouchi, Tsuchiya, and Mizushima (196, 197)), have also been studied. Band positions are given in Table 11, together with polarization data [Krimm and Liang (101) Narita, Ichinohe, and Enomoto (144) Shimanouchi, Tsuchiya, and Mizushima (196)) and data on the 

Polyvinyl chloride (pol-ee-VYE-nul KLOR-ide) is also known as PVC, vinyl, chlorethylene homopolymer, and chlor-ethene homopolymer. It is the third most commonly produced plastic in the United States, exceeded only hy polyethylene and polypropylene. It is offered commercially in a variety of formulations, usually as a white powder or colorless granules. The compound is resistant to moisture, weathering, most acids, fats and oils, many organic solvents, and attack by fungi. It is easily colored and manufactured in a variety of forms, including sheets, films, fibers, and foam. 

Poltj(vintjl chloride). White atoms are hydrogen, black atoms are carbon and green atom is chlorine. Gray stick represents a double bond. 

Russian chemists made some efforts to find useful applications for the compound in the early twentieth century, without much success. The first patent for the production of the compound was awarded to the German chemist Friedrich Heinrich August Klatte (dates not available) in 1913, but Klatte never marketed the product for commercial use. 

The recycling symbol for polyvinyl chloride is the number 3 inside a triangle made of three arrows. 

Goodrich adapted Semon s discovery for two specific applications shoe heels and the coating on chemical racks. Those applications were not profitable enough for Goodrich to continue making polyvinyl chloride. But Semon continued to look for new ways of adapting the compound for additional applications. He was eventually successful and by 1931 the company had begun to turn out a full line of polyvinyl chloride products in most of the forms currently available. 

Polyvinyl chloride (PVC) is often produced by suspension or emulsion polymerisation. It is used extensively in producing PVC pipes for construction. Impact modifiers are often added to strengthen the material. PVC is also used in plastisols for dipped coatings, in shower curtains, and in vinyl leather. Nonvolatile plasticisers are necessary in such applications where the material must remain flexible. Because PVC is a very hydrophobic polymer with good barrier properties, it makes an effective obstacle to oxygen and water vapour in packaging films. 

Gaseous vinyl chloride monomer is polymerised under high pressure conditions. Since polyvinyl chloride polymer is insoluble in its own monomer, the reaction kinetics do not follow the classical emulsion polymerisation kinetics. During polymerisation, chain transfer to monomer is extensive, and molecular weight development depends upon the reaction temperature rather than the initiator concentration. Consequently, lower reaction temperatures are needed to reach higher molecular weights. A typical formulation for the suspension polymerisation of polyvinyl chloride is given in Table 5. 

PVC is responsible for about 50% of plastics consumption of calcium carbonate [8j. In filled PVC, 80% of the mineral market involves CaCOa (ground 70%, precipitated 10%). Important characteristics of GCC are its ready availability in different particle sizes and its low cost It imparts increased stiffness, often without adversely affecting 

PVC is generally not suitable for carbonated juice and soft drinks products because of its creep strength and barrier properties. 

Usually two different polymers do not mix at the segmental level but a favourable interaction between the two polymers can allow one to obtain homogeneous blends. FT-IR is a potential tool for the investigation of the mutual compatibility of various polymers. The small spectral changes due to these interactions can be detected by this method. If two polymers are immiscible, one can synthesise a spectrum of the blend by co-adding, in the appropriate 

Reprinted with permission from W.F. Maddams in Analysis of Polymer Systems, Eds., L.S. Bark and N.S. Allen, Applied Science Publishers, London, 1982, Chapter 3, 59. Copyright 

Reprinted with permission from Developments in Polymer Characterisation, Ed., J. V. Dawkins, Applied Science Publishers, London, 1983, Chapter 3,119. Copyright J.V. Dawkins, 1983 

Reprinted with permission from N.R. Manoj and RR De, Polymer, 1998, 39, 3, 733. Copyright 1998, Elsevier Science Ltd 

The homopolymer of PVC is not readily soluble, and is therefore difficult to bond by solvent-cementing techniques, although a number of solvents and solvent mixtures have been used with varying degrees of success. 

A large number of solvents have been suggested for solvent cementing PVC (given in Table 9.10 ). 

Dissolved chips or shavings of PVC will increase the viscosity of the solution and make the solvent more effective in joining mating surfaces that are not perfectly smooth. Another formulation that will work with either flexible or rigid PVC is hsted in Table 9.12.  

Care must be used in handling this formulation because of the slightly toxic nature of the tetrahydrofuran. Good ventilation is required.  

ASTM D25 64-04 specifies a solvent-cement used for PVC pipe and fittings. No particular solvent is recommended, but a minimum of 10% PVC 

PET waste is recycled using various methods for use in several applications. Chemical recycling enables sustainable development and leads to recovery of the raw materials from which the polymer was made, as well as secondary value-added products [23]. Chemical recycling is generally based on breaking the ester bonds of waste PET using a chemical degradation process such as [24]  

Methanolysis converting PET into dimethyl terephthalate and ethylene glycol (EG). The products of methanolysis are the raw materials needed for the production of PET. The reaction conditions for methanolysis are 2-A MPa and 180-280 °C [25-28]. 

Glycolysis chemical recycling using EG, diethylene glycol, propylene glycol, butanediol and triethylene glycol [29, 30]. The 

Glycolysis consists of the transesterification of PET and the destruction of its polymer chain, resulting in the decrease of its MW. When glycols are used for the depolymerisation of PET, the oligomers obtained have two hydroxyl end groups, i.e., oligoester diols are formed. 

Unsaturated polyester resins are complex polymers resulting from a crosslinking reaction of a liquid unsaturated polyester with vinyl-type monomers, most often a styrene monomer. The unsaturated polyester is formed via the condensation reaction of an unsaturated dibasic acid or anhydride, a saturated dibasic acid or anhydride, and a polyfunctional alcohol [32]. 

Rigid PVC, sometimes called the poor man s engineering plastic, has a wide range of properties for use in different products. In addition to the noteworthy properties mentioned. 

The major applications of the PVAs are in elastomeric products, adhesives, films, and finishes. Extruded PVA hoses and tubing are excellent for use subjected to contact with oils and other chemicals. PVA is used as a sizing in the manufacture of nylon. 

The PVBs are soluble in esters, ketones, alcohols, and chlorinated hydrocarbons but insoluble in the aliphatic hydrocarbons. They are stable in dilute alkalis but slowly decompose in dilute acids. PVBs are widely used as safety-glass interlayers and between sheets of acrylic to protect the enclosures of pressurized cabins in aircraft against shattering. Since 1938, PVB film in interlayers from 10 to 40 mils has been an important resource for the glass, automotive, and architectural industries. PVBs are also used as coatings for textiles and paper and as adhesives. 

In addition, different coupling agents have different effects when calcium carbonate whiskers are processed. The impact strength of the composites filled by stearic acid modified calcium carbonate whiskers is better than that of the composite material filled by titanate coupling agent modified whiskers.  

HCI cleavage and oxygen absorption (related to the initial mass of PVC) in the degradation of PVC powder in oxygen atmosphere at 180 °C [20] 

Therefore, stabilizers always have to be added when processing PVC. They delay dehydrochlorination by binding HCI and eliminating initiation points, suppress autoxidation, and minimize mechano-chemical fragmentation by an internal lubricating action [20], 

Larger polyene sequences may enter into intra- and intermolecular cyclization reactions, so that initially PVC degradation is not necessarily accompanied by chain cleavage [599], 

Oxygen promotes HCI cleavage. Therefore, air increases dehydrochlorination on the other hand, air also retards discoloration and even brightens up slightly discolored PVC, because oxygen also reacts with the polyene groups and thus breaks up conjugated double bond systems [599]. 

Depolymerization with formation of vinyl chloride does not take place. The bond energy of a C-Cl bond is weaker at 317 kj/mol than the bond energy of a C-C bond in the backbone at 348 kJ/mol [20]. 

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The paper discusses the application of dynamic indentation method and apparatus for the evaluation of viscoelastic properties of polymeric materials. The three-element model of viscoelastic material has been used to calculate the rigidity and the viscosity. Using a measurements of the indentation as a function of a current velocity change on impact with the material under test, the contact force and the displacement diagrams as a function of time are plotted. Experimental results of the testing of polyvinyl chloride cable coating by dynamic indentation method and data of the static tensile test are presented. 

Figure 2 shows a typical example of the row data measured by this method The data exhibit a classic curves, namely velocity, contact force and depth of the indenter intrusion, obtained on polyvinyl chloride sample. 

A computer program was written to perform all the calculation. It is found that the three-element viscoelastic model provides reasonable estimation of the behavior of the polyvinyl chloride material during the impact... 

While with-in the mobile x-ray system, the waste in the sampler, is contained within a replaceable (and disposable) polyvinyl chloride (PVC) sleeve with a wall thickness of approximately 0.2-inches and a sealed bottom. It was anticipated that the PVC tube or sleeve would, with use, become highly contaminated with waste residues which drip of fall-off the sampler. The sleeve is coated with a conductive coating to prevent static electricity buildup . There are no sources of ignition in this sealed spare. The sampler (and waste) is coupling which includes a positive pressure gasket. This barrier is further isolated by a second barrier consisting of an epoxy coated aluminum sleeve also sealed-off from the main x-ray cabinet and PVC sleeve. There are also no potential sources of ignition in this isolated secondary space as well. 

Polymers can be classified as addition polymers and condensation polymers. Addition polymers are formed by iiitermolecular reactions of the monomeric units without the elimination of atoms or groups. An example is vinyl chloride, which can be made to combine with itself to yield polyvinyl chloride ... 

Vinyl compounds. Vinyl chloride (prepared from acetylene and hydrogen chloride) 3 ields polyvinyl chloride (P.V.C.), which is employed as a rubber substitute and for other purposes. Vinyl acetate (from... 

One example of a liquid-based ion-selective electrode is that for Ca +, which uses a porous plastic membrane saturated with di-(n-decyl) phosphate (Figure 11.13). As shown in Figure 11.14, the membrane is placed at the end of a nonconducting cylindrical tube and is in contact with two reservoirs. The outer reservoir contains di-(n-decyl) phosphate in di- -octylphenylphosphonate, which soaks into the porous membrane. The inner reservoir contains a standard aqueous solution of Ca + and a Ag/AgCl reference electrode. Calcium ion-selective electrodes are also available in which the di-(n-decyl) phosphate is immobilized in a polyvinyl chloride... 

F. W. Moor, Molybdenum Compounds as Smoke Suppressants for Polyvinyl Chloride, Society of Plastics Engineers (SPE ANTEC), Montreal, Canada, 1977. 

M. J. Rosenfield, Construction of Experimental Polyvinyl Chloride (PHC) Koofing U.S. Army Corps of Engineers, Champaign, Dl., 1984. 

The reaction between urea and Aiming sulfuric acid is rapid and exothermic. It may proceed with violent boiling unless the reaction temperature is controlled. The reactants are strongly acidic. Therefore, operators should wear suitable protective gear to guard against chemical hazard. Special stainless steel, mbber lining, fiber-reinforced plastics, and polyvinyl chloride and carbon equipment are used. 

M. Kaufman, The Chemistry and Industrial Production of Polyvinyl Chloride The History ofPHC, Gordon and Breach Science PubHshers Inc., New York, 1969, pp. 387-388. 

E. M. Smith, ed., Waldo Eonsbury Semon, A Man of Ideas The Inventor of Plasticic d Polyvinyl Chloride, The Geon Co., Cleveland, Ohio, 1993. 

In the suspension polymerization of PVC, droplets of monomer 30—150 p.m in diameter are dispersed in water by agitation. A thin membrane is formed at the water—monomer interface by dispersants such as poly(vinyl alcohol) or methyl cellulose. This membrane, isolated by dissolving the PVC in tetrahydrofuran and measured at 0.01—0.02-p.m thick, has been found to be a graft copolymer of polyvinyl chloride and poly(vinyl alcohol) (4,5). Early in the polymerization, particles of PVC deposit onto the membrane from both the monomer and the water sides, forming a skin 0.5—5-p.m thick that can be observed on grains sectioned after polymerization (4,6). Primary particles, 1 p.m in diameter, deposit onto the membrane from the monomer side (Pig. 1), whereas water-phase polymer, 0.1 p.m in diameter, deposits onto the skin from the water side of the membrane (Pig. 2) (4). These domain-sized water-phase particles may be one source of the observed domain stmcture (7). 

Methyl bromide, when dry (<100 ppm water), is inert toward most materials of constmction. Carbon steel is recommended for storage vessels, piping, pumps, valves, and fittings. Copper, brass, nickel, and its alloys are sometimes used. Aluminum, magnesium, zinc, and alloys of these metals should not be used because under some conditions dangerous pyrophoric compounds may be formed. Many nonmetallic materials are also useful for handling methyl bromide, but nylon and polyvinyl chloride should be avoided. 

LDPE = low density polyethylene LLDPE = linear low density polyethylene HDPE = high density polyethylene PP = polypropylene PVC = polyvinyl chloride PS = polystyrene ABS = polyacrylonitrile-butadiene-styrene. 

H. E. Prey, CEHMarketing Kesearch Keport, Polyvinyl Chloride Eesins, Stanford Research Institute, Menlo Park, Calif., 1988, p. 580.1881G. 

Polyvinyl chloride Polyvinyl chloride (PVC) and chlorinated polyvinyl chloride (CPVC) pipe and tubing are available in sizes 12 in and smaller for PVC and 4 in and smaller for CPVC. They have excellent resistance at room temperature to salts, ammonium hydroxide, and sulfuric, nitric, acetic, and hydrochloric acid but may be damaged by ketones, aromatics, and some chlorinated hydrocarbons. 

A development of interest to the chemical industiy is the tubular precipitator of reinforced-plastic construction (Wanner, Gas Cleaning Plant after T1O2 Rotary Kilns, technical bulletin, Lurgi Corp., Frankfurt, Germany, 1971). Tubes made of polyvinyl chloride plastic are reinforced on the outside with polyester-fiber glass. The use of modern economical materials of construction to replace high-maintenance materials such as lead has been long awaited for corrosive applications. 

Casein 36 B275 Polyvinyl chloride pellets, compounds. 35-55 C16K... 

Cast-iron chips 1.30-200 C37 Polyvinyl chloride resin, dispersion-type 12-18 A.36KPY... 

Cement, Portland 65-85 A27Y Polyvinyl chloride resin, solvent, non-solvent. ... 

Synthetic membrane Polyvinyl chloride, Expensive maybe... 

The important thermoplastics used commercially are polyethylene, acrylonitrile butadiene styrene (ABS), polyvinyl chloride (PVC), cellulose acetate butyrate (CAB), vinylidene chloride (Saran), fluorocarbons (Teflon, Halar, Kel-F, Kynar), polycarbonates, polypropylene, nylons, and acetals (Delrin). Important thermosetting plasttcs are... 

Unplasticized polyvinyl chlorides (type I) have excellent resistance to oxidizing acids other than concentrated and to most nonoxidizing acids. Resistance is good to weak and strong alkahne materials. Resistance to chlorinated hydrocarbons is not good. Polyvinyhdene chloride, known as Saran, has good resistance to chlorinated hydrocarbons. 

Polyvinyl chloride acetate copolymers Tough Very good Excellent Excellent (Aliphatic hydrocarbon, good aromatic hydrocarbon, poor) Fair, ISO F Very good Easy... 

Solutions in contact with polyvinyl chloride can become contaminated with trace amounts of lead, titanium, tin, zinc, iron, magnesium or cadmium from additives used in the manufacture and moulding of PVC. V-Phenyl-2-naphthylamine is a contaminant of solvents and biological materials that have been in contact with black rubber or neoprene (in which it is used as an antioxidant). Although it was only an artefact of the separation procedure it has been isolated as an apparent component of vitamin K preparations, extracts of plant lipids, algae, livers, butter, eye tissue and kidney tissue [Brown Chem Br 3 524 1967]. 

Freeing a solution from extremely small particles [e.g. for optical rotatory dispersion (ORD) or circular dichroism (CD) measurements] requires filters with very small pore size. Commercially available (Millipore, Gelman, Nucleopore) filters other than cellulose or glass include nylon, Teflon, and polyvinyl chloride, and the pore diameter may be as small as 0.01 micron (see Table 6). Special containers are used to hold the filters, through which the solution is pressed by applying pressure, e.g. from a syringe. Some of these filters can be used to clear strong sulfuric acid solutions. 

Polyvinyl chloride [9002-81-2]. Ppted from cyclohexanone by addition of MeOH. 

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