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1Preapred by: Mr. Harminder SinghA polymer is a high molar mass molecular compound made up of many repeating chemical units.Naturally occurring polymersProteinsNucleic acidsCelluloseRubberSynthetic polymersNylonDacronLucite

A polymer is a large molecule made by linking togetherrepeating units of small molecules called monomers

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5Preapred by: Mr. Harminder SinghCharacterizing a PolymerStructure Classification SynthesisStructure of a PolymerSkeletal Structure Chemical StructureSkeletal StructureLinear a chain with two ends

Skeletal StructureBranched have side chains

Skeletal StructureCrosslinked (Networked) chains are connected to other chains

11Preapred by: Mr. Harminder SinghThe simple repeating unit of a polymer is the monomer.

Homopolymer is a polymer made up of only one type of monomer( CF2 CF2 )nTeflon( CH2 CH2 )nPolyethylene( CH2 CH )nClPVC25.2Copolymer is a polymer made up of two or more monomersStyrene-butadiene rubber( CH CH2 CH2 CH CH CH2 )n

14Preapred by: Mr. Harminder SinghClassificationsThermoplasticElastomerThermosetThermoplasticsLinear or branched polymers which can be melted when heat is applied. Can be molded into any shape with processing techniques such as injection molding or extrusion. Most common plasticsThermoplasticsPlastics bottles, grocery bags, water piping, rope, fishing line, car partsMost are recyclable Natural thermoplastics silk, cellulose (proteins), polylactic acidCodes for Plastics1 PETE soft drink bottles2 LDPE plastic bags, toys3 PVC water pipes4 HDPE milk jugs 5 PP bottle caps6 PS styrofoam 1ElastomersCrosslinked (networked) rubbery polymers that can be stretched easily (3-10x original size)Rapidly recover original dimensions when applied stress is released. Low degree of crosslinking

ElastomersUses examination gloves, rubber bands, bouncing ballsNot recyclable Degrades (burns/scorches) when heat is addedNatural elastomers natural rubber, latexThermosetsNormally are rigid materials. Network polymers in which chain motion is greatly restricted by a high degree of crosslinking. Cannot be reshaped once formed. epoxy

ThermosetsUses high temperature electrical applications, super glue, counter top laminates, epoxy resins, tires (vulcanized rubber) Cannot be recycled (burn/scorch with heat)Natural* thermosets vulcanized rubber

PolymerizationAddition PolymerizationCondensation Polymerization23Preapred by: Mr. Harminder SinghPolyadditionReactions in which monomers combine without the elimination of a small molecule. Usually involves the breaking of a double bond.Polyaddition with RadicalsInitiation Creation of an active site (free radical).Propagation Growth of polymer chain by addition of a monomer to an active site and the creation of a new active site. Polyaddition with RadicalsTermination Growth of chain stops. Combination Two growing chains collide.Disproportionation A hydrogen atom is added to the end of a growing chain.

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Occurs in the presence of a Lewis acid32Preapred by: Mr. Harminder Singh

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36Preapred by: Mr. Harminder SinghPolycondensationReactions in which small molecules (H2O, HCl) are eliminated when the monomers combine. e.g. Nylon66

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40Preapred by: Mr. Harminder SinghProperties and usesGood fibre-forming material and is converted into commercial fibres.Such fibres have high stretch resistance, high crease and wrinkle resistance.Highly resistant to mineral and organic acid, but is less resistant to alkalies.Used for making synthetic fibres like terylene, dacron etc.For blending with wool to provise better crease and wrinkle resistance.A glass reinforcing material in safety helmets, aircraft battery boxes, etc.

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