Temperature control in polyvinyl chloride production. Polyvinyl chloride is produced by polymerization of the vinyl chloride monomer vcm, as shown. B reaction is that used to make cocacola bottles i. The site of initiation in vinyl chloride polymerization. Polyvinyl chloride pvc is the third most commonly produced polymer and is important because of its mechanical characteristics. Unreacted vcm is pumped out of the reactor and condensed, and noncondensable gases are vented from the condenser. Addition polymerization is the successive addition of alkene monomers to one another. Pvc is widely used in construction because it is cheap. Polyvinyl chloride via precipitation polymerization. Polyvinyl chloride pvc free download as powerpoint presentation.
Some poly mers, like poly vinyl chloride or polyacrylonitrile, are insoluble in the. Pdf kinetics and mechanism of bulk polymerization of vinyl. As a building material, pvc is cheap, durable, and easy to assemble. Mechanisms of bulk and emulsion polymerization are discussed.
The polyvinyl chloride pvc suspension polymerization process is an exothermic reaction which is carried out in a batch reactor. Addition polymerization an overview sciencedirect topics. The process for emulsion polymerization of vinyl chloride monomer vcm to produce polyvinyl chloride pvc has been used for decades, yet information concerning the monomer and the reaction mechanism has only recently begun to appear in the chemical literature. Pvc formula mechanism of reaction process the production of pvc involves several stages. Notice how every other carbon must have a chlorine attached. The ethylene solution and the completely predissolved chlorine are mixed in the reaction zone of the riser and react to edc in a fast liquidphase reaction which significantly lowers byproduct formation. The manual adjustment of the vcm flow rate by means of. A method is disclosed for producing polyvinyl chloride which includes mixing a vinyl chloride solution with an initiator solution in at least one high shear mixing device comprising at least one rotorstator set producing a rotor tip speed of at least 5. The reaction produces cpvc, which has thermal and chemical properties that are superior to pvc.
Polyvinyl chloride pvc uses, benefits, and safety facts. Temperature dependence of apparent solubility constant for nbutane in pvc. Theterm polyvinyl chloride, or pvc, indicates homopo1ymers of vinyl chloride and incorrectly copolymers containing amow1ts of vinylidene chloride, vinyl acetage, ethylene, propylene or acrylates. Polyvinyl chloride production membrane technology and. Modified polyvinyl alcohol as a dispersant in suspension. However, this transfer step does not result in a controlled or a narrow mwd. Negatively charged sulfate groups were introduced to. Ihs economicsl the economic bene2ts of polyvinyl chloride in the united states and canada introduction polyvinyl chloride also called vinyl or simply pvc is a versatile thermoplastic material that is used in the production of hundreds of products that consumers encounter in everyday life and many more that are encountered less frequently but. Therefore, the degree of polymerization is strongly governed by the polymerization temperature.
A latex of two particle sizes is obtainableone about 1x which is grown on 0. The plastics and rubber are examples of the most common polymers which are commonly used in both everyday life and in medical applications. It is a vinyl polymer constructed of repeating vinyl groups ethenyls having one of their hydrogens replaced with a chloride group. Vinyl chloride polymerization macsphere mcmaster university. Polyvinyl chloride pvc is produced by polymerization of vinyl chloride monomer vcm. The reactions of poly vinyl chloride pvc with different aliphatic amines in tetra hydro furan, thf, have been studied. Addition polymerization is the addition of simple molecules monomers to form long chain molecules polymer.
Presentation on manufacturing of polyvinyl chloride pvc various methods used in the manufacture process. Around the world, over 50% of pvc manufactured is used in construction. Synthesis and characterization of polyvinyl chloride. Wo2016106964a1 method for preparing polyvinyl chloride. This breakthrough material was brought about to substitute for metals, glass, wood, natural fibers, papers and fabrics. Highly chlorinated polyvinyl chloride as a novel precursor. In terms of revenue generated, it is one of the most valuable products of the chemical industry. Kinetics and mechanism of bulk polymerization of vinyl. Experimental part materials all monomers were vacuum distilled over cah2 and stored. Surface modification of polyvinyl chloride sheets via. The mixtures of polyvinyl alcohol pva with thermooxidatively modified polyvinyl alcohol b or acetalized polyvinyl alcohol d were used as the dispersants in suspension vinyl chloride homopolymerizations in compositions at w r total, vc 0.
Enomoto and asahina previously studied the mechanism of vc addition by use of partially or completely deuterated monomers and infrared spectroscopy. Polyvinyl chloride pvc is one of the most widely used polymers in the world. However, the high cost of these polymer precursors 8,9, or the resulting low carbonisation yield and mechanical properties 7 of the obtained. Polyvinyl chloride pvc is produced from vinyl chloride monomer vcm by a poly merization reaction. Polyvinyl chloride is produced by polymerization citation needed of the vinyl chloride monomer vcm, as shown. Addition reactions with other halogens at the double bond, for instance, to yield 1,1,2trichloroethane or. Paper open access modification and characterization of. Introduction to polyvinyl chloride polyvinyl chloride pvc was first manufactured in germany in 1931 as a robust and lightweight new plastic. The pvc backbone remained intact during atrp because the secondary chlorine on the pvc backbone is too strongly bonded to initiate the polymerization by reaction with cui complex. The rigid form of pvc is used in construction for pipe and in profile. Condensation polymerization is a reaction that joins two functional groups such as an alcohol and a carboxylic acid and forms a second small molecule such as water.
Polyvinyl chloride, iupac polychloroethene commonly abbreviated pvc, is a widely used thermoplastic polymer. The term polymer is defined as very large molecules having high molecular mass. If the resulting polymer has more than one molecule in the chain, it is usually referred to as a copolymer. When discussing the progress of step polymerization, it is not meaningful to use conversion of monomer as a measure because the reaction will still proceed even though all the monomer has been consumed. Kinetics and mechanism of bulk polymerization of vinyl chloride in a polymerization reactor article pdf available in journal of engineering research 122. These reactions led to the formation of new polymers pvcl which were characterized by spectroscopic methods infra red, ir and uvvisible spectrophotometry. Lecture notes synthesis of polymers chemical engineering.
Minor sources include storage and handling facilities for vc and pvc and plants producing ethylene diamine or ethylene dichloride. The exact properties of polymers depends on a variety of chemical. Due to its versatile nature, pvc is used extensively across a broad range of industrial, technical and everyday applications including widespread use in building, transport, packaging, electricalelectronic and healthcare applications. The prepolymer is then transferred to a horizontal autoclave equipped with a slow. Polyvinyl chloride an overview sciencedirect topics. Second only to pe in production and consumption, pvc is manufactured by bulk, solution, suspension, and emulsion polymerization of vinyl chloride monomer, using freeradical initiators. The green complex formed by reaction of polyvinyl alcohol with boric acid has been used to detect small amounts in polyvinyl chloride. Polyvinyl chloride, iupac polychloroethanediyl commonly abbreviated pvc, is a thermoplastic polymer. Kinetics and mechanism of bulk polymerization of vinyl chloride in. The principal emission sources, in order of importance, are vc production plants, polyvinyl chloride pvc polymerization facilities, and plants where pvc products are fabricated. Polymerization reactions to form pvc are the most important reactions from an industrial view see section 3.
Polymers polymers are the high molecular weight compounds obtained by repeated union of simple molecules. Polymerization is a chemical process in which two or more monomers are combined to form a large repetitive polymer molecule. Polyvinyl chloride wikidwelling fandom powered by wikia. Pvc is used in the manufacture of numerous products, including packaging films and water pipes. Us8147768b2 system and process for production of polyvinyl. In batch polymerization, there may occur unexpected thermal reactive runaway. Pdf polyvinyl chloride pvc is the third most commonly produced polymer and is important because of its mechanical characteristics. Major industrial polymers polyvinyl chloride pvc britannica. Vinyl chloride is an organohalogen compound that has important industrial applications. The reaction to make polypropylene h 2 cchch 3 is illustrated in the middle reaction of. Pvc suspension resins are usually relatively dustfree and granular with varying degrees of particle porosity. Polyvinyl chloride is the third most widely produced plastic, after polyethylene and polypropylene.
Composite of the new polymers were prepared and their optical activities in the region 200 400 nm were studied. Pvc polyvinyl chloride, which is found in plastic wrap, simulated leather, water pipes, and garden hoses, is formed from vinyl chloride h 2 cchcl. Polyvinyl chloride pvc british plastics federation. Regnault in france first produced vinyl chloride monomer in 1835 and baumann first recorded its polymerisation in 1872 after exposing sealed tubes containing the monomer to sunlight.
Therefore, slurry discharged from the polymerization reactor is dehydrated, dried. Therefore, there is a difficulty in controlling the behavior of the system in order to keep. This is a plastic that has the following chemical formula. The effect of emulsion process formulation ingredients on the morphology, structure, and properties of polyvinyl chloride pvc powder has been considered in this study. In freeradical polymerization in bulk, solution, and aqueous suspension the initiator is dissolved in the monomer. The simplest approach in these cases is to meltblend the plastic with a suitable rubber using an. An atrp initiator containing a chloropropionate moiety was chemically tethered onto the surface of pvc via a novel wet chemical modification. Kinetics and mechanism of bulk polymerization of vinyl chloride in a polymerization reactor. Polyvinyl chloride pvc polyvinyl chloride polymerization. Synthesis and characterization of graft copolymers of poly. In addition to synthetic polymers, such as, polyvinyl chloride, polystyrene, nylon and teflon, we also find natural polymers all around us in the form of proteins and dna.
When treated with certain catalysts, vinyl chloride monomers undergo polymerization and form the larger compound known as polyvinyl chloride, or pvc. Being a very well known membr of the family of vinyl polymers. Aqueous suspension poly merization is considered as bulk polymerization in droplets. Polyvinyl chloride pvc, a major plastics material which finds widespread use in building, transport, packaging, electricalelectronic and healthcare applications. Polyvinyl chloride production membrane technology and research. Vinyl chloride suspension polymerization is a common reaction in polymer industry. Polyvinyl chloride pipe fittings, clear film for meat packaging condensation polymerization and hydrolysis the chemical mechanism that cells use to make and break polymers are basically the same. Polyvinyl chloride pvc is one of the significant thermoplastic polymers and widely used because of its versatile nature, low price, good performance, wide property range and can be modified within broad limits from rigid and hard to rubberelastic and soft. The present work was performed to add to the knowledge of vcm emulsion polymerization. Depending on the temperature and pressure of the condenser, the vent stream also contains from 50 to 2,000 lbh of vcm. The economic bene ts of polyvinyl chloride in the united. Polymerization of vinyl chloride wiley online library. Vinyl chloride ch2chcl is most often obtained by reacting ethylene with oxygen and hydrogen chloride over a copper catalyst.
Alternative approaches are needed for polyvinyl chloride pvc, nylons, and many other thermoplastics, where the chemistry of polymerization does not lend itself to incorporation of a rubber by precipitation from solution or by emulsion grafting. In the first stage, vinyl chloride monomer is mechanically agitated in a vertical autoclave with the appropriate initiators until a conversion of 7 10% is achieved. Pdf kinetics and mechanism of bulk polymerization of. Major industrial polymers major industrial polymers polyvinyl chloride pvc. Vinyl chloride polymerization in microdroplet reactor core. Starch, polyvinyl chloride, polyethylene, nylon 6, 6 and etc. Polyvinyl chloride economical, versatile polyvinyl chloride pvc, or vinyl is used in a variety of applications in the building and construction, health care, electronics, automobile and other sectors, in products ranging from piping and siding, blood bags and tubing, to wire and cable insulation, windshield system components and more. The major issue with this process is that fact that the catalyst used, mercuric chloride, is a. Polyvinyl chloride pvc or vinyl is an economical and versatile thermoplastic polymer widely used in building and construction industry to produce door and window profiles, pipes drinking and wastewater, wire and cable insulation, medical devices, etc. Over 30 million tons of pvc is used around the globe today, both in. All of the raw materials and water for this reaction must be fi ltered during production to ensure a quality end product. Heat is removed by continuously condensing the vcm vapour above the liquid reaction mixture. Since about 57% of its mass is chlorine, creating a given mass of pvc requires less petroleum than many other polymers. The reaction to make polypropylene h 2 cchch 3 is illustrated in.
The polymerization process or path is determined by the required characteristics and application of the end product. Polyvinyl chloride of all synthetic thermoplastics, polyvinyl chloride pvc is probably one of the polymers in modern use with the oldest pedigree. Pvc is a very durable and long last construction material, which can be used in a variety of applications, either rigid or flexible, white or black and a wide range of colours in between. Any unreacted vcm is recovered through further separation, and recycled back into the process. Us3522227a us3522227da us3522227a us 3522227 a us3522227 a us 3522227a us 3522227d a us3522227d a us 3522227da us 3522227 a us3522227 a us 3522227a authority us united states prior art keywords polymerization autoclave monomer agitator agitation prior art date 19630226 legal status the legal status is an assumption and is not a legal conclusion. Gatta and coworkers discovered that it is possible to produce also a poly vinyl chloride of a single large particle size by seeding. Surface modification of polyvinyl chloride sheets via growth. Plastic covers a wide rage of synthetic or semisynthetic polymerization products i. A method for preparing polyvinyl chloride by suspension and polymerization, and a feeding device. The addition reaction may occur by way of radical, cationic, or anionic intermediates. First, there are the addition polymers, which are formed by addition reactions that link together monomers containing multiple bonds. The manufacture of the basic monomer is not considered part of the plastics industry and is usually. The most common method of pvc manufacturing is the process of suspension. Freeradical polymerization in bulk, solution, and suspension.
409 1233 966 1237 1270 667 93 687 6 830 280 606 1345 1490 482 1563 1239 410 853 854 1076 1224 136 1085 1194 20 1338 989 143 1319 1126 1027 309 343 1019