Poly many mer units Polymers are many units
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“Poly” = many “mer” = units Polymers are many units called monomers that can be easily connected into long chains. They are giant molecules usually with carbons building the backbone.
POLYMERS (the whole train) are made out of MONOMERS (individual cars of the train) joined together.
Ü Polymer: High molecular weight molecule made up of a small repeat unit (monomer). Ü A-A-A-A-A-A-A-A-A-A-A-AÜ Monomer: Low molecular weight compound that can be connected together to give a poymer
Natural Vs Synthetic Polymers
Cotton fiber is mostly cellulose, and cellulose is made of chains of the sugar, glucose linked together a certain way.
Natural Polymers – found in nature and can be extracted ÜSilk ÜNatural Rubber ÜAmber ÜWool ÜMolecules of life: proteins and DNA
Natural Polymers
Properties of Natural Polymers Properties of plastics : - Breaks Down more easily v Wool is good heat insulator v Silk is satiny texture v Cotton – good air circulation and absorption of moisture v
Synthetic Polymers derived from crude oil and made by scientists ÜVelcro ÜSpandex ÜKevlar ÜPolyester ÜNylon ÜSaran
Range of Synthetic Polymers Ü Traditionally, the industry has produced two main types of synthetic polymers – plastics and rubbers. Ü Plastics are (generally) rigid materials Ü Rubbers are flexible materials which exhibit long- range elasticity.
Properties of Synthetic Polymers Properties of plastics : - Light v Strong v Easily molded and shaped and be coloured v Inert (unreactive) to chemical v Insulators of electricity and heat v Cheap v Able to resist corrosion v Special properties can be made according to specific needs v
Human and Environmental Impact The Pros and Cons
Positive Impacts of Synthetic Polymers Ü Manufacturing: of plastic articles involving less energy than that necessary for the same production from traditional materials Ü Fuel Consumption: lightweight properties reduce fuel consumption in vehicles and space travel Ü Construction: non-corrosive plastics play a major role in the construction Ü Medical: Artificial limbs Ü Environmental: New Research for Oil Spills Ü Convenience: Everyday items (toothbrush, shower curtain) Ü Sports: Improvement to equipment and performance Ü http: //www. youtube. com/watch? v=cmlun. Cb. BV_o
The Negative Impacts of Synthetic Polymers Disposal problems Most of the polymers are non-biogradeable Cannot be decomposed by bacteria / decomposer So… caused disposal problem when polymer not decay Derived from Oil –non-renewable resource – Blockage of rivers Plastics items discarded Blockage of drainage systems & rivers Diseases Polymer containers not buried in the ground Become breeding ground for mosquitoes
Harmful to animals The non-biogradeable polymers thrown into rivers -> lakes -> seas Swallowed by aquatic animals Animals die due to choking https: //youtu. be/d 2 J 2 qd. Or. W 44 Pollutions Open burning of polymers Released harmful, poisonous gases Cause air pollution Contributes to acid rain
What you can do? 1. Recycle 2. Avoid the use of single use plastics 3. Plastics can be burned as fuel 1. Use degradable plastics
CATEGORY Code Example DENSITY 1 PETE Pop bottle Peanut butter jar Mylar 1. 38 – 1. 39 2 HDPE Milk jug Shampoo bottle 0. 95 – 0. 97 3 V 4 LDPE Trash bags Diaper liners 0. 92 – 0. 94 5 PP Indoor/outdoor carpeting, kitchenware 0. 90 – 0. 91 6 PS Styrofoam Pen casing Clear plastic cups 1. 05 – 1. 07 7 OTHER Toothpaste and cosmetic containers Pipes and fittings, pill bottles, shower curtains, garden hoses, tile, leather like luggage and upholstery 1. 15 – 1. 35
Polymer structures Linear, Branched, Crosslinked
Things that are made of polymers look, feel, and act depending on how their atoms and molecules are connected. Some are rubbery, like a bouncy ball, some are sticky and gooey, and some are hard and tough, like a skateboard.
By using different starting materials and processing techniques, we can produce polymers having different molecular structures
Linear Polymer Ü Microwaveable food containers, Teflon, Garden Hoses, Dacron carpets and Kevlar ropes. Sturdy and rigid structure. Ü In reality, the number of monomer units in a polymer commonly ranges from 1, 000 to 10, 000 or more.
Branched Polymer Ü Soft, flexible due to looser structure. Shampoo and ketchup bottles and milk jugs, plastic food wrap. To find some other examples, look on food containers and other plastics for the LDPE (low-density polyethylene)
Cross-linked Polymer Ü Lightly cross linked – flexible rubber. Heavily cross linked the more rigid and hard plastic. Two or more long chain polymer chains connected by chemical bonds that are not easily broken. Silly putty, Car Tires, Bowling balls.
Plastics are sudivided into Elastomers Thermoplastic Thermoset
Elastomer Polymer that can regain its original shape after being stretched or pressed at room temperature. Fancy word for Rubber
Range of Polymers Üthermoplastics and thermosets
Thermosets Ü Extensive cross-linking formed by covalent bonds. Ü Bonds prevent chains moving relative to each other. Ü Material that cures or hardens when heated. Ü Chemical resistance, thermal stability, and overall durability
Thermoplastics (80%) Ü No cross links between chains. Ü Weak attractive forces between chains broken by warming. The Material softens (becomes pliable when heated and can be remoulded. Ü. Therefore can be melted down and recycled
Range of Polymers Ü Another way of classifying polymers is in terms of their form or function
Polymerisation The chemical process that joins the monomers together Addition Polymerisation Condensation Polymerisation Uses of polymers
Addition Polymerisation l Many molecules of monomers are added together l A monomer has to have a double bond –alkene l Only the polymer is produced (no other product)
Polyethene / Polyethylene Monomer: ethene
Ethylene has two carbons; plus, instead of the two carbons sharing just one electron each, they share two electrons each. High temperature or UV light can cause two of these shared (paired) electrons to become unshared (unpaired). H H C C H H - - - - H unpaired. Helectrons are These eager to pair up with another electron. If this. Cethylene molecule C bumps another ethylene molecule, the unpaired electrons will cause H it bumped H into to lend one the one of its inner electrons. - -
Here’s another way to see the chain reaction. These are the carbon atoms with their double-bond (2 shared electrons each). The hydrogen atoms are not shown. A collision breaks the first bond. Once the first double bond is broken, a chain reaction will occur. In about a second an entire chamber of compressed ethylene gas turns into the polymer, polyethylene.
Polyvinylchloride l Monomer: vinyl chloride
Addition Polymerisation You are expected to be able to do the following things with addition polymers: l Predict the repeating unit of the polymer given the monomer l Predict the monomer from the polymer – displayed formula l Pg 102 # 1, 2, 3
Condensation Polymers l Involves 2 monomers that have different functional groups. l They also involve the elimination of water or another small molecule (ex. H 2 O, HCl) l Monomer A + Monomer B Polymer + small molecule (normally water - dehydration). l Common condensation polymers include polyesters (the ester linkage) and polyamides (the amide linkage as in proteins).
Polyester is a another copolymer. It is made from equal amounts of two different monomers. Polyester is used to make bottles and fabrics.
Recall: Esterification Reaction
Polyester is made from the two monomers, terephthalic acid (note: “ph” is silent) and ethylene glycol (car antifreeze). This makes a popular plastic called PETE, which is short for Polyethylene Terephthalate. The synthesis is also a dehydration reaction because water is given off. PETE O H O C ESTER groups formed Hence the name POLYESTER
Polyesters l The ester linkage is formed between the monomers of a diol and a diacid.
Polyamides l These involve the linkage of two monomers through the amide linkage as in proteins (e. g. nylon, kevlar)
Polymers: Proteins Polymerization of a protein: putting simple monomers together. monome r Where will the monomers JOIN TOGETHER?
Polymers: Proteins Polymerization of a protein: putting simple monomers together. monome r Where will the monomers JOIN TOGETHER?
Polymers: Proteins Polymerization of a protein: putting simple monomers together. Water drops out to allow the bonds to form.
Polymers: Proteins Polymerization of a protein: putting simple monomers together.
Nylon 6, 6 a polyamide
Nylon-6, 6
Kevlar a polyamide
Uses of polyamides l The main use of polyesters and polyamides is as fibres in clothing. l Most clothing now has a degree of manufactured fibres woven into the natural material (such as cotton). l This gives the material more desirable characteristics, such as stretchiness, and better washability. l Pg. 111 # 1, 2, 3
- Antigentest åre
- Triangle quadrilateral pentagon hexagon octagon
- Application and processing of polymers
- Polymers product design
- Polymers are
- Typical properties of polymers
- Thermoplastic polymers examples
- Crystallinity
- Synthetic organic polymers
- Styrene based polymers
- Homochain polymers
- "mc polymers"
- Big six polymers
- Polymerization in dentistry
- Designer polymers
- Vahe gabuchian
- About polymers
- Commodity plastic
- Orlon monomer
- Thermosoftening plastics examples
- History of biomaterials
- Geosynthetics polymers
- Rubbery polymers
- Z-polymers
- Homochain polymers
- Draw the polymeric backbones of silicones and phosphagenes
- Xmold
- Molecular weight distribution of polymers
- Natural polymers
- Structure polymer
- Polymer examples of proteins
- Meros polymers
- Tablet definition
- "natural polymers"
- Shaping processes for plastics
- Surgical needle holder specialty polymers
- Osmometry molecular weight determination
- Poly methyl 2-cyanopropenoate
- Water soluble antiscalant polymers
- Molecular weight units
- Properties of polymers
- Cross linked polymers definition
- Discordance jard sur mer
- Mer locadora de veiculos
- Partons la mer est belle origine
- Manoeuvre homme à la mer
- Ron wyatt faux
- Cochon de mer
- Nude descending a staircase
- Gksel
- Mer noire
- Atributos multivaluados base de datos
- Seçkisiz olmayan örnekleme yöntemleri
- Institut universitaire européen de la mer
- Pierrot lunaire impressionism or expressionism
- La statue regarde la mer
- Chien de mer roussette
- Les toiles de mer
- Axl mer
- Le vieil homme et la mer