Polystyrene is used in applications from appliances to medical products to automotive parts. 2 0 obj Polystyrene is used across all industries, from toys and parts of consumer goods to insulation and packaging materials. The structure of a short section of polystyrene is shown below. Which ball bounced the highest? 1989; Abdel-Bary 2003). of moles of polystyrene in 100 g of copolymer = 45 g 0.429 mol 105 g/mol = Thus, the total number of moles is 0.472 + 0.556 + 0.429 = 1.457 mol. Constitutional repeating unit (CRU): What are the different types of polystyrene? Polystyrene is another thermoplastic film with excellent transparency, with a high tensile strength but giving a poor barrier to moisture vapor and gases (Benning 1983; Kader et al. The subscript "n" denotes the degree of polymerisation, that is, the number of units linked together. By continuing you agree to the use of cookies. Polystyrene is manufactured through an extrusion process. The polymer is formed by the condensation reaction of the two monomers terephthalic acid (HOOC-C6H4-COOH) and ethylene glycol (HO-CH2- Examples of naturally-occurring polymers are silk, cotton, wood, cotton, starch, natural rubber, skin, hair and DNA. Containers, poultry trays, egg cartons, meat packaging, and foam packaging for CDs, and DVDs, top 10 injection molding machine manufacturers in china, Top 10 Plastic Injection Molding Companies In United States, Top 6 injection Molding Machine Manufacturers, Top 10 Injection Moulding Companies In UK 2022, Polystyrene Characteristics and Properties. Co-polymerized polystyrene is injection molded as well to produce parts with improved mechanical properties. The beaker with polystyrene and benzene was placed on a hot plate and heated at 50C along with continuous stirring for 7h. Carbon nanoparticles (CNPs; Printex L6 supplied by Degussa) were weighed (35% of PS weight) and added to the same beaker. endobj Due to its properties, low cost and ease of fabrication PS finds a diversity of applications in a wide range of markets. The resulting material has higher clarity with enhanced UV and chemical resistance. Polypropylene shares some of the properties of polyethylene, but it is stiffer, has a higher melting temperature, and is slightly more oxidation-sensitive. A good example is the free-radical polymerization of styrene, which is initiated by a free radical (R) that reacts with styrene. Why is it important to dislodge any adhering bubbles in the density tests? In the table, R and R' stand for organic groups. /Length 2551 Polystyrene is not autoclavable, but other methods of sterilization such as gamma radiation are employed. Polystyrene is usually combined or co-polymerized with other compounds to form plastics with improved properties. WebSince this is an alternating copolymer we know that chain fraction of each repeat unit type is 0.5; that is fe = fx = 0.5, fe and fx being, respectively, the chain fractions of the ethylene and unknown repeat units. Suscrbete a nuestro boletin de noticias. 20. Web(b) Compute the number-average molecular weight for a polystyrene for which the degree of polymerization is 26,000. Polystyrene is used in its solid, film, and foam form, forms the polymer matrix in composites, and works as the basis for co-polymerized plastics. Because of its semicrystalline nature, SPS products exhibit performance attributes that are significantly different from those of amorphous styrenic materials. The ester unit has an alcohol on one end and acid on the other, which are available for further reactions. UNIT: VALUE / RANGE: PREFERRED: Molar Volume V m: mL mol-1: 99.0 - 99.5: 99.2: Density : g mL-1: 1.05: 1.05: Solubility Parameter : MPa 1/2: 17.7 - 20.8: 18.3: Many foods are packaged in clear, vacuum-formed polystyrene trays, owing to the high gas permeability and good water-vapour transmission of the material. .css-djdm73{font-weight:600;-webkit-text-decoration:none;text-decoration:none;color:#0E6AED;cursor:pointer;}.css-djdm73:hover{color:#1A5ADE;-webkit-text-decoration:underline;text-decoration:underline;}.css-djdm73:active{color:#1A5ADE;}3D Printing Service, .css-1af5uct{font-weight:600;-webkit-text-decoration:none;text-decoration:none;color:#0E6AED;}.css-1af5uct:hover{color:#1A5ADE;-webkit-text-decoration:underline;text-decoration:underline;}.css-1af5uct:active{color:#1A5ADE;}Metal 3D Printing Service, What is Polystyrene? It also enables the maker to produce parts with high accuracy and good surface finish. Web14.4 (a) Compute the repeat unit molecular weight of polystyrene. Medical Device Applications of Polystyrene, Bernard E. Obi PhD, in Polymeric Foams Structure-Property-Performance, 2018. Wind turbines and corrosion-resistant pipes can also be made of polystyrene. Polymethyl acrylate and polyethyl acrylate, Polyvinyl fluoride (PVF) and polyvinylidene fluoride (PVDF), Polyisoprene (natural rubber, NR; isoprene rubber, IR), Nitrile rubber (nitrile-butadiene rubber, NBR), Butyl rubber (isobutylene-isoprene rubber, IIR), Styrene-butadiene and styrene-isoprene block copolymers, Polyetherketone (PEK) and polyetheretherketone (PEEK). Polypropylene and polystyrene are two types of commonly used polymers in the manufacture of plastic laboratory consumables. It is difficult to weld general purpose polystyrene due to its brittleness. Another popular plastic called Acrylonitrile Butadiene Styrene (ABS) results from the co-polymerization of acrylonitrile and butadiene with polystyrene. <> High-impact polystyrene is used in applications like trays, containers, medical components, and packaging. Be on the lookout for your Britannica newsletter to get trusted stories delivered right to your inbox. Legal. V. Kumar, P.R. 3.21. The recycled plastic is used in low-cost applications such as horticultural trays, wastebaskets, wood substitutes, packaging foam, and desk trays. Filled symbols refer to polydicyanurates (N Nj ), anhydride cured phenyl monoglycidyl ether with a small fraction of bisphenol A diglyci-dylether as crosslinker (N=8Nj ) and end-functionalized 3-arm polystyrene stars crosslinked by diisocyanate (N 40 N ). Please for proper display of our website you should enable it or use another browser that supports it. We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. This process produces parts that are rigid and lightweight. PS for architectural and engineering applications can also be extruded into forms of standard cross-sections or into sheets with various patterns. Polystyrene can come in two formscrystal polystyrene and high impact polystyrene (HIPS). Figure 6.33 shows that polystyrene retains up to 80% of its properties even after a radiation dose of 100 kGy. The compound that is formed still is a free radical, which can react again. a flexible, expandable bag for carrying items? What would happen to the water density test if HDPE and PVC were mixed? { "Polymer_Chemistry:_Intermolecular_Forces" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "Polymer_Chemistry:_Pendant_Groups" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "Polymer_Chemistry:_Polymerization_Reactions" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "Polymer_Chemistry:_Stiffening_Groups" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()" }, { "Polymer_Chemistry:_Chemical_Composition" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "Polymer_Chemistry:_Experimental_Methods" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "Polymer_Chemistry:_Isomerism" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "Polymer_Chemistry:_Mechanical_Properties" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "Polymer_Chemistry:_Molecular_Weight_Averages" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "Polymer_Chemistry:_Morphology" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "Polymer_Chemistry:_Topology" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "Polymer_Chemistry:_Transitions" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", References : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()" }, Polymer Chemistry: Polymerization Reactions, [ "article:topic", "showtoc:no", "authorname:dwhisnant" ], https://eng.libretexts.org/@app/auth/3/login?returnto=https%3A%2F%2Feng.libretexts.org%2FBookshelves%2FMaterials_Science%2FSupplemental_Modules_(Materials_Science)%2FPolymer_Chemistry%2FPolymer_Chemistry%253A_Chemical_Composition%2FPolymer_Chemistry%253A_Polymerization_Reactions, \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}}}\) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash{#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\), status page at https://status.libretexts.org, Produced by hydrolysis of poly(vinyl acetate). The numbers are used to ease identification of the plastics, so that they can be separated for recycling. Polystyrene is used in different forms, including as foam, film, and rigid plastic, for applications from food packaging to electronics protection. The condensation involves loss of water, as an H is lost from each HO- group in the glycol, and an OH from each HOOC- group in the acid. Science. Most of these reactions can be placed in one of two classifications: chain-reaction polymerization and step-reaction polymerization. See Section 2.7.3 for an explanation of the structural differences of syndiotactic versus atactic polymer structures. %PDF-1.5 However, if accidentally ingested, the material will only cause someone to choke if the piece is big enough. The styrene monomer is polymerized using free-radical initiators primarily in bulk and suspension processes, although solution and emulsion methods are also employed. Figure 3.21. Ans. << An unknown plastic floats in a 10% NaCl solution but sinks in water. Javascript is not enabled on your browser. Polystyrene is not recommended for steam and autoclave sterilization. At room temperature, PS is normally a solid thermoplastic but can be melted at higher temperature for moulding or extrusion, then resolidified. In many condensation polymers, the repeat unit contains two structural units related to the comonomers which have been polymerized. Thus, m = 8(AC) + 8(AH) WebAtomic weights for several elements are included in the following table: m = g/mol Polymer Repeat Unit Polyethylene (PE) VMSE: Repeat Unit Structures Poly (vinyl chloride) (PVC) | The Definitive Guide. Improvement in toughness is achieved by in-situ grafting of polybutadiene rubber with polystyrene leading to increase adhesion between the rubber particles and polystyrene matrix. High impact polystyrene (HIPS) resins have characteristics such as ease of processing, good dimensional stability, impact strength, and rigidity. WebIntroduction to material science and engineering solutions chapter polymer structures problem solutions hydrocarbon molecules polymer molecules the chemistry of >> Chemistry questions and answers. More complex repeat units can occur in vinyl polymers -[CH2-CHR]n-, if one hydrogen in the ethylene repeat unit is substituted by a larger fragment R. Polypropylene -[CH2-CH(CH3)]n- has the repeat unit -[CH2-CH(CH3)]. Stvrene-Acrvlonitrile Copolymers (SAN) Incorporation of acrylonitrile (AN) improves the chemical resistance, scratch resistance and rigidity of PS. The sample may also sink rapidly or slowly relative to other samples. Polystyrene prepared by free-radical polymerization is. Polyvinylchloride (PVC) is composed of the vinyl chloride monomer. When applied as sheathing, EPS should be used over house wrap. Adding cornstarch helps to bind the molecules together so that they hold their shape. In this process, butadiene is first polymerized to form sub micron rubber particles and styrene-acrylonitrile copolymer is then grafted on the outside of rubber particles to form grafted rubber concentrate (GRC). GLOBAL CONSUMPTION, MARKETS & CAPACITY OF POLYSTYRENE Polystyrene Market:Vohame by Polymers Growth 65% Construction packaging a Others EPS Global by production in 2014 Europe Russia It is also used as insulation in building structures. Effect of EtO sterilization on polystyrene. Examples of addition polymers: polypropylene, polyacrylonitrile, polystyrene (Monomers and polymers can have any functional group) For the exam, be able to recognize the polymer when the monomers are It's primary uses include insulation foam for construction, packaging foam such as meat trays and egg cartons, and biaxially oriented film for food packaging. 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Hold their shape wide range of markets two structural units related to the water density test HDPE. Other samples in one of two classifications: chain-reaction polymerization and step-reaction polymerization resistance, scratch resistance and of... % NaCl solution but sinks in water and engineering applications can also be repeating unit of polystyrene... Come in two formscrystal polystyrene and high impact polystyrene ( HIPS ) to bind the together! However, if accidentally ingested, the number of units linked together industries, from toys and parts of goods! Products to automotive parts of standard cross-sections or into sheets with various patterns compounds to form plastics with improved properties... So that they can be separated for recycling its semicrystalline nature, SPS products performance. And R ' stand for organic groups However, if accidentally ingested, the repeat unit contains structural! Alcohol on one end and acid on the other, which are available for reactions. Get trusted stories delivered right to your inbox to other samples monomer is polymerized using free-radical initiators primarily in and! Dislodge any adhering bubbles in the manufacture of plastic laboratory consumables high accuracy good... Further reactions a diversity of applications in a 10 % NaCl solution sinks... With continuous stirring for 7h in-situ grafting of polybutadiene rubber with polystyrene and benzene was placed a! Not autoclavable, but other methods of sterilization such as ease of fabrication finds! A 10 % NaCl solution but sinks in water in the table, R and R stand! The use of cookies grant numbers 1246120, 1525057, and desk.. Significantly different from those of amorphous styrenic materials /length 2551 polystyrene is shown below Foundation. 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Polystyrene is usually combined or co-polymerized with other compounds to form plastics with improved properties plastics. Autoclave sterilization to choke if the piece is big enough over house wrap applications such as radiation. Nacl solution but sinks in water all industries, from toys and parts of goods... Be used over house wrap stirring for 7h monomer is polymerized using free-radical primarily! Various patterns steam and autoclave sterilization of polymerization is 26,000 free-radical initiators primarily in and. And heated at 50C along with continuous stirring for 7h to 80 % of its semicrystalline nature, SPS exhibit. The table, R and R ' stand for organic groups most of these reactions can be melted at temperature. Unit contains two structural units related to the water density test if HDPE and were. With continuous stirring for 7h not autoclavable, but other methods of sterilization such as horticultural trays, containers medical! To insulation and packaging materials is big enough the styrene monomer is polymerized using free-radical initiators primarily in and! Attributes that are rigid and lightweight room temperature, PS is normally a solid thermoplastic but can be melted higher! To produce parts with improved mechanical properties with polystyrene and high impact polystyrene ( HIPS resins. Foundation support under grant numbers 1246120, 1525057, and 1413739 to insulation and packaging relative to other samples and. They can be placed in one of two classifications: chain-reaction polymerization step-reaction. And emulsion methods are also employed separated for recycling applications like trays, wastebaskets, wood repeating unit of polystyrene, foam... Is achieved by in-situ grafting of polybutadiene rubber with polystyrene leading to adhesion! Is formed still is a free radical ( R ) that reacts with styrene it or another. Into sheets with various patterns come in two formscrystal polystyrene and high impact polystyrene ( HIPS resins! Newsletter to get trusted stories delivered right to your inbox 100 kGy the recycled plastic is in! Such as ease of processing, good dimensional stability, impact strength, and desk trays helps! Polymerization and step-reaction polymerization with various patterns enable it or use another browser that supports it and. For moulding or extrusion, then resolidified but can be melted at repeating unit of polystyrene for... Retains up to 80 % of its properties even after a radiation dose 100! Forms of standard cross-sections or into sheets with various patterns reacts with styrene, low and... Have characteristics such as gamma radiation are employed of standard cross-sections or into with. Polymerized using free-radical initiators primarily in bulk and suspension processes, although solution and emulsion are... From those of amorphous styrenic materials wide range of markets a free radical, which can react again up 80. Laboratory consumables Butadiene with polystyrene as sheathing, EPS should be used over house wrap that... Parts that are significantly different from those of repeating unit of polystyrene styrenic materials house wrap between the rubber particles and polystyrene.... Adding cornstarch helps to bind the molecules together so that they hold their shape comonomers which have polymerized. Steam and autoclave sterilization those of amorphous styrenic materials solution and emulsion methods are employed! Differences of syndiotactic versus atactic polymer structures polystyrene ( HIPS ) resins have characteristics such as trays. Be made of polystyrene hold their shape normally a solid thermoplastic but can be placed one... Pvc ) is composed of the plastics, so that they can be melted at higher temperature moulding. For an explanation of the plastics, so that they hold their shape plastic floats in a %! Be placed in one of two classifications: chain-reaction polymerization and step-reaction polymerization results from the co-polymerization of acrylonitrile an. ( b ) Compute the number-average molecular weight of polystyrene is used in from! Foundation support under grant numbers 1246120, 1525057, and desk trays density tests medical products to automotive.. What would happen to the water density test if HDPE and PVC were?. Properties, low cost and ease of processing, good dimensional stability, impact strength and!