The structure and adhesive properties of poly vinyl acetate dispersion modified with organosilicon compounds. The number of units so combined is typically between 100 and 5,000. Laboratory tests were carried out to evaluate the effect of polyvinyl acetate on swellingshrinkage properties of expansive soil. Polymers are essentially large molecules linked together in such a way that they are very strong and durable. The physical characteristics of the product depend on the. It is well known that pva particles cannot be prepared by direct polymerization of vinyl alcohol. A series of shrinkswell tests were performed with adding.
Polyvinyl chloride acetate usually contains 8595% vinyl chloride. Overview of materials for polyvinyl chloride polyvinyl. Pvc is the worlds thirdmost widely produced synthetic plastic polymer, after polyethylene and polypropylene. Polyvinyl acetates are lowcost adhesives with high initialtack properties. Poly vinyl acetate pvapolyol were blended by weight 3. Dec 19, 2015 the properties of polyvinyl acetate depend on the extent or degree of its hydrolysis, specifically whether it is full or partial figure 1, which in turn dictates its categorization into two groups, namely, a partially hydrolyzed and b fully hydrolyzed. Poly vinyl acetate pva polyol were blended by weight 3. Ratios of complexed to free borate species at different. Synthomers polyvinyl acetates homopolymers and acid copolymers of vinyl acetate. Poly1acetoxyethylene, polyethenyl ethanoate, poly1acetyloxiethene. Preparation of polyvinyl alcohol from local raw material. Bond strength is much higher than that of the wood itself.
Polyvinyl acetate is a synthetic polymer that is a basic component of some types of glue, which is popular for certain properties such as elasticity and flexibility at room temperature. Polyvinyl alcohol pva is watersoluble polymer manufactured by the saponification of polyvinyl acetate. Apr 19, 2012 polyvinyl alcohol pva is a synthetic polymer derived from polyvinyl acetate through partial or full hydroxylation. Polyvinyl acetate is a synthetic polymer that is a basic component of some types of glue, which is popular for certain properties such as elasticity and flexibility at. Polyvinyl alcohol pvoh, pva, or pval is a watersoluble synthetic polymer. Polyvinyl alcohol, pva, is the most frequently used material in embolization of tumors, aneurisms and arteriovenous malformations due to its low toxicity, good biocompatibility and desirable physical properties. Polyvinyl acetate resins and copolymers are also used as hotmelt adhesives, sealants, fabric finishing, plastic wood, and inks. The conditions of the acetal reaction and the concentration of the particular aldehyde and polyvinyl alcohol used. Vinyl acetate 108054 hazard summary vinyl acetate is primarily used as a monomer in the production of polyvinyl acetate and polyvinyl alcohol. Polyvinyl acetate, a synthetic resin prepared by the polymerization of vinyl acetate. Polyvinyl acetate may be used as is or modified through. Overview of materials for polyvinyl chloride polyvinyl acetate copolymer, this property data is a summary of similar materials in the matweb database for the category polyvinyl chloride polyvinyl acetate copolymer. The result of this study was a proposed mechanism stating that the packing of polymer chains was.
Processing once the base emulsion polymer is obtained, it is then mixed with all other liquid ingredients and additives except for the fillers. Polyvinyl alcohol can be converted to different esters, or it can be reacted with aldehydes, such as butyraldehyde or formaldehyde, to form acetals. The emulsion polymerization of vinyl acetate possesses the rather typical properties in comparison the emulsion polymerizations of the comonomers. Thermal properties of polyvinyl acetate 50 matrix and using different fibre contentsg. Individual polymer chains are formed by covalent bonds, which are strong bonds. Safety assessment of polyvinyl alcohol as used in cosmetics. Methanol is mainly used as a solvent in the polymerization process hydrolysis process. Polyvinyl acetate mw 450,000 is a hydrophobic polymer and is also referred to as pvac.
When handled properly, vam can be stored, transported and otherwise managed safely. Pdf the structure and adhesive properties of polyvinyl acetate. Hence, it is often utilized as the starting point for the creation of other resins such as polyvinyl butyral pvb or polyvinyl formal pvf. It is polymerized with freeradical initiators, primarily in emulsion processes, and forms the polymer phase in waterbased paints. Effect of polyvinyl acetate on mechanical properties and characteristics of polylactic acidnatural rubber blends article pdf available in journal of polymers and the environment 212. In its most important application, polyvinyl acetate serves as. Acute shortterm inhalation exposure of workers to vinyl acetate has resulted in eye irritation and upper respiratory tract irritation. Pdf exfoliated polyvinyl acetatemontmorillonite nanocomposite. It should be noted that the 24mm films tested were made from solutions of polyvinyl acetate in 2butanone, which is not an emulsion. Thus polyvinyl acetate can be treated with alkali, which gradually results in polyvinyl alcohol and the alkali acetate. Synthesis of polyvinyl alcohol andor polyvinyl acetate. It is a clear, colorless liquid with a sweet, fruity smell. Accepted 6 december 1972 summarypolyvinyl acetate and iodine form a characteristic red complex in the presence of potassium iodide.
Pdf among many polymeric adhesives used in wood processing industry polyvinyl acetate has a rather wide application. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed. It is a nonstructural adhesive with low price, convenient usage and wide application range. These polymers will achieve superior performance in a wide range of solventbased adhesives, including hobby glues, parquet floor and laminating. Polyvinyl acetate is a substance produced through the combining of many units of monomeric vinyl acetate ch3coochch2. To enhance the properties of different hydrolyzed pva grades, it is generally chemically modified with various crosslinkers. Expired lifetime application number inventor marcel bouchard. Basic physical properties of pvoh resin polyvinyl alcohol. Vinyl acetate has been related to reproductive abnormalities. Study of crosslinking between boric acid and different types. In making slime, the individual polymer chains are bound together by weak hydrogen bonds. It does not cover the group of polyvinyl based adhesives which are suitable for bonding flexible films. Polyvinyl acetate is manufactured by radical polymerization using vinyl acetate as a raw material and then hydrolyzing it under an alkaline condition. Viscosity will vary by product from a low range of 50200 cps to a high of 20004000 cps.
Effect of polyvinyl acetate stabilization on the swelling. Polyvinyl alcohols are highmolecularweight resins containing various percentages of hydroxyl and acetate groups produced by hydrolysis of polyvinyl acetate. Polyvinyl acetate is synthesized by the emulsion polymerization of vinyl acetate monomer vam. Pdf synthesis and characterization of polyvinyl acetate. Polyvinyl alcohol is a resin, a natural or synthetic organic compound made of noncrystalline or viscous substance. Among many polymeric adhesives used in wood processing industry polyvinyl acetate has a rather wide application.
Pvac polyvinyl acetate pvac resinnitchen chemicals a. Definition polyvinyl alcohol is a synthetic resin prepared by the polymerization of vinyl acetate, followed by partial hydrolysis of the ester in the presence of an alkaline catalyst. Polyvinyl chloride acetate is used in similar applications as pvc but it has less need for plasticizers. Solution and bulk properties of branched polyvinyl acetates part 1. Vinyl acetate monomer vam is a high volume building block chemical used in the manufacture of polyvinyl acetate or vinyl acetate copolymers. Pva is commonly used in medical devices due to its low protein adsorption characteristics, biocompatibility, high water solubility, and chemical resistance. Polyvinyl alcohols are high molecular weight resins containing various percentages of hydroxyl and acetate groups produced by hydrolysis of polyvinyl acetate. Polyvinyl alcohol is obtained by hydrolysing polyvinyl acetate.
They are thermoplastic solids with a range of molecular weights, typically supplied in the form of small beads. The complete dissolution of pva in water is bound by its intrinsic properties, which require the water temperature to. Search results for polyvinyl acetate at sigmaaldrich. The complete dissolution of pva in water is bound by its intrinsic properties, which require the water temperature to be at 100 c with a holding time of 30 min 23. Polyvinyl alcohol, also known as pvoh, pva, or pval, is a synthetic polymer that is soluble in water. The task for the panel at this meeting is to determine whether the original conclusion on polyvinyl alcohol of safe as used. Complexation of polyvinyl acetate with iodine pdf free download. 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. 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.
Pva is one of very few high molecular weight commercial polymers that are water soluble, the basic properties of pva such as water solubility depend on the. Polyvinyl acetate constitutes a class of polymers that can entirely dissolve in water to form a solution. Books by hand polyvinyl acetate pva blick art materials. Waterbased emulsions are, by far, the most common form in which polyvinyl acetates are used in the adhesive market. A polymer is a long molecule that is mostly made up of many similar repeating units. Preparation of polyvinyl acetate modified by triethoxyvinylsilane and properties of copolymeric lattices article pdf available in iranian polymer journal 163 march 2007 with 252 reads. Pdf waterborne polyvinyl acetate wood flooring adhesive. Spectrophotometry of the complex at 510 nm in a methanolwater system at 20 yields linear calibration curves over the range 25100 mg of polyvinyl acetate per 1.
Polyvinyl acetate came into widespread use in adhesives in the 1940s as a synthetic resin substitute for hide glue. Vinyl acetate is an industrial chemical that is produced in large amounts in the united states. Polyvinyl alcohol has excellent film forming, emulsifying, and adhesive properties. Polyvinyl acetate an overview sciencedirect topics. Pvb has an adhesive quality and is a waterresistant, plastic film, which is often used. The basic properties of pvoh are typically governed by the degree of polymerization. These polymers are the base for many industrial and consumer products as well as for other polymers. It is a skin and upper respiratory tract irritantand a central nervous system depressant. In this experiment, a polymer polyvinyl alcohol chemically reacts with borax to form a crosslinked polymer network. Kuraray poval and elvanol resins are produced by converting polyvinyl acetate into polyvinyl alcohol through the saponification process. It is insoluble and does not strongly swell as other extended release polymers such as xanthan gum, guar gum or locust bean gum, and hydroxyalkylated or carboxyalkylated cellulosic excipients. Polyvinyl alcohol slime gelfand center carnegie mellon. Equation for the calculation of the degree of hydrolysis. Different polymers with versatile properties are attractive because of their introduction and potential uses in many.
Elmers is made up of polyvinyl acetate, which is a synthetic polymer. The north koreanmanufacture fiber vinalon is produced from polyvinyl alcohol. Polyvinyl alcohol is produced commercially from polyvinyl acetate, usually by a continuous process. It is a colorless solid with good resistance to water, acids, and alkalis.
Properties and applications of polyvinyl alcohol, halloysite. Professional quality adhesive dries acidfree, solventfree, and watersoluble. Thermal properties of polyvinyl acetate pva and toluene. This is mixed with different percentages of prepared sulfonatedphenol formaldehyde resin spf. Polyvinyl acetate pvac, a synthetic resin prepared by the polymerization of vinyl acetate. Vinyl acetate has high water solubility, a high monomerpolymer swelling ratio, and a high chain transfer constant. Polyvinyl acetate pvac dispersions are low price, zero for. Despite its inferior properties as a clothing fiber, it is produced for selfsufficiency reasons, because no oil is required to produce it. Vinyl acetate is used to make other industrial chemicals.
Pdf the structure and adhesive properties of polyvinyl. Polyvinyl acetate pva and polyvinyl alcohol pvoh are further examples of. Pvac emulsions are best known for their use in wood glues or school glues due to their strong adhesion properties. The monomer vinyl acetate ch 2 cho 2 cch 3 is prepared from ethylene by reaction with oxygen and acetic acid over a palladium catalyst. This information focuses on the chemical and physical properties of the material and the handling and safety aspects pertinent to its use in a polymerization system. Polyvinyl acetate phthalate c12h12o6 cid 161821 structure, chemical names, physical and chemical properties, classification, patents, literature, biological. The structure and adhesive properties of polyvinyl acetate dispersion modified with organosilicon compounds article pdf available january 2003 with 4,140 reads how we measure reads.
It is very flammable and may be ignited by heat, sparks, or flames. The percentage of acetate groups determine the hydrolosis levels which is how we determine our grade characteristics. This translates to an average molecular weight of between 850 and 40,000. Study of crosslinking between boric acid and different. Polyvinyl acetate pvac emulsion is a type of waterbased environmentfriendly adhesive. Along with saponification alkaline hydrolysis of fatty acid esters of the acetyl moieties of polyvinyl acetate, monomer residuals are getting eliminated as well. Identification of the substancemixture and of the companyundertaking 1. The mixture was prepared on clean glass substrate as a bulk films, at different thicknesses.
It has no odor and is not toxic, and is resistant to grease, oils, and solvents. 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. The adhesive properties are greatly affected by the molecular weight distribution and the compatibility of the vinyl acetate with other ingredients. Summary information is provided on vinyl acetate as the primary ingredient in the manufacture of the polymer. Polyvinyl acetals are prepared from aldehydes and polyvinyl alcohols. Commercial grades of polyvinyl alcohol differ in the degree of polymerisation molecular mass and degree of hydrolysis residual polyvinyl acetate content. In its most important application, polyvinyl acetate serves as the filmforming ingredient in waterbased latex paints. Osp polyvinyl acetate polymers osp polyvinyl acetate polymers are typically shipped at a total solids content of 5456%. The physical characteristics and its specific functional uses. Celanese is a global leader in polyvinyl acetate homopolymer emulsions, often called pvac or occasionally pva homopolymers.
The physical properties and its specific application depend on the degree of hydrolysis. Thermal properties of the nanocomposite were studied by using differential. The glass transition temperature of polyvinyl acetate is between 30 and 45 c depending on the molecular weight. Polyvinyl alcohol was first prepared by hermann and haehnel in 1924 by hydrolyzing polyvinyl acetate in ethanol with potassium hydroxide. A minor fraction of polyvinyl alcohol ends up in the manufacture of polyvinyl acetales, e. Learn more about polyvinyl acetate in this article. The conditions of theacetal reaction and concentration of the particular aldehyde and polyvinyl alcohol used are. Mar 09, 2020 polyvinyl acetate, a synthetic resin prepared by the polymerization of vinyl acetate. Properties under alkaline conditions, boron compounds such as boric. Temperatures and related properties of polystyrene. Thermal properties such as thermal conductivity are important parameters to simulate the temperature variation inside the composite.
It is used to glue tenon joints, doors, windows and other wooden articles. Cosolvent gellike materials from partially hydrolyzed. Us3497521a preparation of polyvinyl acetate adhesive. Solution and bulk properties of branched polyvinyl acetates.
Polyvinyl acetate 29 polyperfluoropropylene 11 polymethyl acrylate 9 polyvinylidene chloride 17 polyvinyl fluoride 20 poly1butene 25. Polyvinyl acetate is prepared by polymerization of vinyl acetate. 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. The production capacity within the eu is reported to be 100,000 ta. It is effective in film forming, emulsifying, and has an adhesive quality. Mar 08, 2020 polyvinyl acetate is a thermoplastic polymer commonly used in glues, paint, and a number of industrial adhesives. Additional properties are high initial tack, almost invisible bond line, softening at 3045c, good biodegradation resistance, poor resistance to creep under load, and low cost. In this study, polyvinyl acetate as a nontraditional chemical stabilizer was used in soil improvement.