The emulsion polymerization kinetics of vinyl acetate and. Synthsis and properties of polyvinyl acetate emulsion. The effect of polyvinyl alcohol on the rate of polymerization, maximum conversion as. Polyvinyl acetate by emulsion polymerization aqueous reactants preparation section. Abstract an emulsion polymerization system with uniform continuous addition of vinyl acetate monomer, pluronic f68 surfactant, and persulfate initiator has. Celanese is a global leader in polyvinyl acetate homopolymer emulsions, often called pvac or occasionally pva homopolymers. Vinyl acetate emulsions stanchem polymers emulsion. Polyvinyl acetate may be used as is or modified through. Polyvinyl acetate emulsion adhesive has been widely used due to its good bonding. To prepare a commercial product with economic and technical relevance, polyvinyl acetate pvac was synthesized, under our laboratory conditions, updating an industrial prescription by emulsion polymerization of vinyl acetate using polyvinyl alcohol as emulsifier, fenton reagent as reaction initiator and acetic acid as aqueous phase phregulator. Pdf synthesis and characterization of polyvinyl acetate. In a process for the emulsion polymerization of vinyl acetate in the presence, as emulsifier, of a water soluble partially hydrolyzed polyvinyl acetate, the improvement which comprises polymerizing vinyl acetate monomer in aqueous emulsion with, as polymerization initiator, a combination of.
Synthesis and characterization of polyvinyl acetatemontmorillonite nanocomposite by in situ emulsion polymerization technique article pdf available in polymer bulletin 669. The degree of polymerization of polyvinyl acetate is typically 100 to 5000, while its ester groups are sensitive to base hydrolysis and slowly convert pvac into polyvinyl alcohol and acetic acid. Polyvinyl acetate and polyvinyl alcohol by richard g. Assaad and others published use of polyvinyl acetate polymers in sustainable concrete made with recycled aggregates find, read and cite all the research you need. The role of polyvinyl alcohol in emulsion polymerization. Pvac emulsions are best known for their use in wood glues or school glues due to their strong adhesion properties. Pdf in this study, the emulsion homopolymerization system containing vinyl acetate, potassium persulfate, a new cationic polymeric surfactant and. It is a nonstructural adhesive with low price, convenient usage and wide application range. The industrial importance of vinyl acetate latexes makes the mechanism and kinetics of their emulsion polymerization of practical as well as scientific interest. Emulsion polymerization of vinyl acetate download ebook. A model experiment of emulsion polymerization of vinyl acetate vac was carried out using polyvinyl alcohol pva as a protective colloid, where a small amount of vac 1 ml100 ml water was employed.
In particular, it is one of the most widely used polymers for the colloidal stabilization of vinylacetatebased emulsions table 6. Chemical engineering 160260 polymer science and engineering. This invention relates to a method for making a high solids content, low viscosity, storage stable polyvinyl acetate emulsion in the absence of a protective colloid and employing a solubilizing comonomer and at least one emulsifier. The kinetics of emulsion polymerizations are responsible for the evolution of high molecular weight material and it is hoped that this work can cast further light on the kinetics of the emulsion polymerization of vinyl acetate. An industrial polymerization process for the production of polyvinyl alcohol stabilized polyvinylacetate dispersions has been examined to investigate the influence of the startup temperature on production process and latex characteristics. The stabilizing efficiency of this nonionic copolymer as surfactant was tested in the emulsion polymerization of vinyl acetate and styrene monomers in the presence of potassium persulfate k 2 s 2 o 8 as initiator. Semicontinuous vinyl acetate vac radical emulsion polymerization in water with 3methacryloxypropyltrimethoxysilane gf31 comonomer was performed using protective colloid pva and surfaceactive compound. Because of its good adhesion to a number of substrates, and to some extent because of. Effect of polyvinyl alcohol of different molecular weights. Improvement in wood bonding strength of poly vinyl.
Synthesis of ultrahighmolecularweight pva using two. The emulsion polymerization of each of vinyl acetate and butyl. The product investigated is a high solids, high viscosity latex, obtained by a semibatch emulsion polymerization process, initiated with persulfate. Polyvinyl alcohol was first prepared by hermann and haehnel in 1924 by hydrolyzing polyvinyl acetate in ethanol with potassium hydroxide. Emulsion polymerization of styrene st and vinyl acetate vac in the presence of conventional polyvinyl alcohol pva, pva modified with a terminal alkyl group or pva modified with a terminal thiol group hs. Major industrial polymers major industrial polymers polyvinyl chloride pvc. Increasing pvac emulsion polymerization productivityan. When pvac is incorporated into emulsion coatings and adhesives, it is normally converted to polyvinyl alcohol first, which is a watersoluble polymer. Polyvinyl acetate pvac homopolymer and copolymer emulsions prepared in the presence of pvoh have a number of different applications including adhesives, paints, and textile finishes.
Emulsion polymerization of vinyl acetate in the presence of poly. Pdf characterization of polyvinyl alcohol during the. For polymeric materials the bonding of adhesives can be compared to welding, bolting and other techniques used for metals. In the presence of the large amounts of pva, the number of new particles smaller than 80 nm continued to increase during the. Synthsis and properties of polyvinyl acetate emulsion copolymers by three novel nonionic functional polyurethane surfactants 1283 korean j. Efficacy of initiation by persulfate in vinyl acetate emulsion polymerization. The impact of gf31 on polyvinyl acetate pvac dispersion physicochemical and production parameters were determined. Emulsion polymerization of vinyl acetate in the presence. The number of units so combined is typically between 100 and 5,000. In its most important application, polyvinyl acetate serves as the filmforming ingredient in waterbased latex paints. Vinyl acetate emulsion polymerization and copolymerization.
Pdf modeling of polyvinyl acetate polymerization process. Pdf emulsion polymerization of vinyl acetate in the presence of a. The bulk polymerization of vinyl acetate is not used in industrial operations due to the violent reaction obtained. Particle size and molecular weight distributions author. The rate of polymerization was found to be proportional to. However the unwanted bulk polymerization of vinyl acetate is involved in many industrial accidents where the polymerization occurred in storage vessels containing fresh or recycled. 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. A new research on biodegradable, renewable, environmentally friendly starch stabilized polyvinyl acetate emulsion that was synthesized by the graft polymerization of vinyl acetate onto starch. The emulsion polymerization of vinyl acetatevac in the presence and absence of polyvinyl alcoholpva as emulsifier was carried out using. Polyvinyl acetate pvac emulsion is a type of waterbased environmentfriendly adhesive. Polyvinyl alcohol is produced commercially from polyvinyl acetate, usually by a continuous process. Emulsion polymerization is a type of radical polymerization that usually starts with an emulsion incorporating water, monomer, and surfactant.
The emulsion fluid can then instantly be processed as a polyvinyl acetate polymer in products comprising the pvac as a constituent element. Us3497521a preparation of polyvinyl acetate adhesive. Other emulsion polymerization methods including micro, mini and inverseemulsion polymerization were mentioned, followed by the description of main emulsion polymerization processes comprising batch, semicontinuous, continuous and seeded, and their application types. Emulsion polymerization of vinyl acetate in the presence of polyvinyl alcohol as emulsifier. Not so good estimates are obtaine d at the beginning and at the. Emulsion polymerization of vinyl acetate springerlink. Emulsion polymerization of vinyl acetate with renewable raw materials as protective colloids hanna lange 7 2 introduction 2. Emulsion polymerization is a widely used process for the production of rubber, plastic, coating, and adhesives in industry 15.
Emulsion polymerization, kinetics, nucleation, viscosity, calculations an extensive literature exists on the subject of the emulsion polymerization of vinyl acetate. Synthesis of ultrahighmolecularweight pva using twostage photoconcentrated emulsion polymerization of vinyl acetate chinan lin, chaurray wu and hsiaochi tsai graduate institute of textile engineering, feng chia university, 100 wenhwa road, seatwen, taichung 40724, taiwan. Study on the initial stage of emulsion polymerization of. Wo1998025976a2 method for making a polyvinyl acetate. The glass transition temperature of polyvinyl acetate is between 30 and 45 c depending on the molecular weight.
Polyvinyl acetate an overview sciencedirect topics. Emulsion polymerization of vinyl acetate with renewable. The kinetics of emulsion polymerization of vinyl acetate in the presence of polyvinyl alcohol pva of different molecular weights as protective colloid using potassiumpersulphate acetone sodium bisulphite as a redox initiation system was studied. Mechanism of vinyl acetate emulsion polymerization french 1958. Because pvoh is synthesized from polyvinyl acetate, a. Thus more than 45 years after the first commercial production of vinyl acetate latexes, their use is still growing, both in actual quantities and different applications. Emulsion polymerization of vinyl acetate and styrene. Chemical engineering 160260 polymer science and engineering lecture. Polyvinyl acetate, a synthetic resin prepared by the polymerization of vinyl acetate. This translates to an average molecular weight of between 850 and 40,000. This corresponds to the initial stage of the emulsion polymerization.
Emulsion polymerization of vinyl acetate mohamed s. Polyvinyl acetate adhesives pvac polyvinyl acetate latex known as white latex is made of vinyl acetate monomer, water, dispersing agent, polymerization starter, and other auxiliary materials mixed together through emulsion polymerization. Table of contents about the company 1 our promise 1 sekisui specialty chemicals 1. Learn more about polyvinyl acetate in this article. Control over size and polydispersity in these applications is required because of the close relationship between the properties of the polymer and the particle size. Us3497521a us3497521da us3497521a us 3497521 a us3497521 a us 3497521a us 3497521d a us3497521d a us 3497521da us 3497521 a us3497521 a us 3497521a authority us united states prior art keywords emulsion polyvinyl acetate polymerization emulsifier vinyl acetate prior art date 19670304 legal status the legal status is an assumption and is not a legal conclusion. Pdf use of polyvinyl acetate polymers in sustainable. Emulsion polymerizations of vinyl acetate vac were performed by fully or partially replacing polyvinyl alcohol. Polyvinyl acetate is a substance produced through the combining of many units of monomeric vinyl acetate ch3coochch2. Initiator systems effect on particle coagulation and. Owing to the fascinating properties of polyvinyl alcohol pva, it was used as a protective colloid to provide the initial stage of the emulsion polymerization. It does not cover the group of polyvinylbased adhesives which are suitable for bonding flexible films. This site is like a library, use search box in the widget to get ebook that you want.
Grafting and adsorption of polyvinyl alcohol in vinyl. Effects of polymerization variables on the properties of vinyl acetate based emulsion polymers 37 rubber company, was the first to be granted a patent to produce a synthetic rubber in the presence of soap as emulsifying agent 4. Polyvinyl acetate is synthesized by the emulsion polymerization of vinyl acetate monomer vam. Modeling of polyvinyl acetate polymerization process for contro l purposses 5 dynamics of the real o ne. Secondly, the emulsion polymerization of vinyl acetate was given. Click download or read online button to get emulsion polymerization of vinyl acetate book now. Pdf w links294k add to acs chemworx sponsored access latex particle nucleation and growth. Vinyl chloride ch2chcl is most often obtained by reacting ethylene with oxygen and hydrogen chloride over a copper catalyst. Used for styrene, methyl methacrylate, vinyl chloride, vinyl acetate kinetics are the same as in the bulk. For more detailed information on specific applications, the preparation of. Understanding vinyl acetate polymerisation accidents. Vinyl acetate emulsion polymerization and copolymerization with acrylic monomers provides a collection and logical organization of the published data much of it formerly found fragmented throughout various journals and little of it referenced in general emulsion polymerization books.
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