Polymers

Polymers PA Standards PA Standards A: Physical Science, Chemistry, and Physics A: Physical Science, Chemistry, and Physics B: Inquiry and Design B: Inquiry and Design C: Humans and the Environment C: Humans and the Environment “Paper or Plastic?” “Paper or Plastic?” Apply concepts about the structure and properties of matter. Apply concepts about the structure and properties of matter. Evaluate experimental information for appropriateness and adherence to relevant science processes. Evaluate experimental information for appropriateness and adherence to relevant science processes. Analyze how pollution has changed in quality, variety and toxicity as the United States developed its industrial base. Analyze how pollution has changed in quality, variety and toxicity as the United States developed its industrial base.

Key Questions What is a Polymer? What is a Polymer? What does a polymer look like on the molecular level? What does a polymer look like on the molecular level? What are the characteristics of polymers? What are the characteristics of polymers?

What is a Polymer?

History and Significance of Polymers What is a polymer? What is a polymer? A polymer is something made of many units (ex. chain)A polymer is something made of many units (ex. chain) Each link is a monomer (“mer”) or basic unitEach link is a monomer (“mer”) or basic unit Made of carbon, hydrogen, oxygen, and/or silicon Made of carbon, hydrogen, oxygen, and/or silicon To make a chain, many “mers”, or links, are hooked, or polymerized, togetherTo make a chain, many “mers”, or links, are hooked, or polymerized, together

History and Significance of Polymers Examples Examples NaturalNatural Tar, tortoise shells, horns, tree saps that produce amber and latex Tar, tortoise shells, horns, tree saps that produce amber and latex Can be processed with heat and pressure Can be processed with heat and pressure Chemically altered beginning in the 1800s Chemically altered beginning in the 1800s Vulcanized rubber, gun cotton, celluloidVulcanized rubber, gun cotton, celluloid SyntheticSynthetic First synthetic polymer produced was Bakelite in 1909 First synthetic polymer produced was Bakelite in 1909 First semi-synthetic fiber, rayon, developed in 1911 First semi-synthetic fiber, rayon, developed in 1911 World War II cut off availability of natural sources of latex, wool, silk World War II cut off availability of natural sources of latex, wool, silk Nylon, acrylic, neoprene, polyethylene, etc. began to be usedNylon, acrylic, neoprene, polyethylene, etc. began to be used

What does a polymer look like on the molecular level?

The Structure of Polymers Composed of hydrocarbons Composed of hydrocarbons Carbon makes up the backbone of the moleculeCarbon makes up the backbone of the molecule Hydrogen atoms bonded along backboneHydrogen atoms bonded along backbone Simplest polymer structure is polyethyleneSimplest polymer structure is polyethylene Polymers may only have carbon and hydrogen Polymers may only have carbon and hydrogen Ex. Polypropylene, polybutylene, polystyrene, and polymethylpenteneEx. Polypropylene, polybutylene, polystyrene, and polymethylpentene

The Structure of Polymers Oxygen, chlorine, fluorine, nitrogen, silicon, phosphorous, and sulfur may also be found in a polymer Oxygen, chlorine, fluorine, nitrogen, silicon, phosphorous, and sulfur may also be found in a polymer Polyvinyl chloride (PVC) – chlorinePolyvinyl chloride (PVC) – chlorine Nylon – nitrogen and oxygenNylon – nitrogen and oxygen Teflon – fluorineTeflon – fluorine Polyesters and polycarbonates – oxygenPolyesters and polycarbonates – oxygen Vulcanized rubber and thiokol – sulfurVulcanized rubber and thiokol – sulfur May also have silicon or phosphorous backbone (inorganic polymer) May also have silicon or phosphorous backbone (inorganic polymer) Ex. Silly Putty TM is silicon basedEx. Silly Putty TM is silicon based

Polymerization Addition Polymerization Addition Polymerization Ex. polyethyleneEx. polyethylene 1. Initiation – “mers” begin to bond together 1. Initiation – “mers” begin to bond together a promoter or catalyst may be needed to start or speed up a reaction a promoter or catalyst may be needed to start or speed up a reaction 2. Propagation – continued addition of monomers into chains 2. Propagation – continued addition of monomers into chains 3. Termination – all monomers are used and the reaction ceases 3. Termination – all monomers are used and the reaction ceases Condensation Polymerization Condensation Polymerization Ex. nylon, polyesters, urea, formaldehydeEx. nylon, polyesters, urea, formaldehyde As monomers join, a small molecule is eliminated As monomers join, a small molecule is eliminated

Molecular Structure Molecular Structure: Molecular Structure:

Molecular Structure Example: Example: Propylene is the monomer of polypropylenePropylene is the monomer of polypropylene percent of all polypropylene polymers have this configuration90-95 percent of all polypropylene polymers have this configuration

Molecular Arrangement of Polymers Amorphous Arrangement Amorphous Arrangement No long-range order or formNo long-range order or form (think of how spaghetti noodles look on a plate) (think of how spaghetti noodles look on a plate) Generally TransparentGenerally Transparent Food wrap, Plexiglass, headlights, contact lenses Food wrap, Plexiglass, headlights, contact lenses Low melting pointsLow melting points Crystalline Arrangement Crystalline Arrangement Distinct pattern; higher degree of crystallinity, the less light can pass throughDistinct pattern; higher degree of crystallinity, the less light can pass through Translucent and OpaqueTranslucent and Opaque High melting pointsHigh melting points

What are the characteristics of polymers?

Characteristics of Polymers Most polymers have the following general attributes. Most polymers have the following general attributes. 1. Polymers can be very resistant to chemicals.1. Polymers can be very resistant to chemicals. Consider warning labels on cleaning fluids (ex. when chemical comes in contact with skin or eyes) Consider warning labels on cleaning fluids (ex. when chemical comes in contact with skin or eyes) 2. Polymers can be both thermal and electrical insulators.2. Polymers can be both thermal and electrical insulators. Consider wiring in your house or handles of pots and pans Consider wiring in your house or handles of pots and pans 3. Generally, polymers are very light in mass with varying degrees of strength.3. Generally, polymers are very light in mass with varying degrees of strength. Ex. Toy or structure of Space Station. Nylon Pantyhose or Kevlar Bulletproof Vests Ex. Toy or structure of Space Station. Nylon Pantyhose or Kevlar Bulletproof Vests 4. Polymers can be processed in various ways to produce thin fibers or very intricate parts.4. Polymers can be processed in various ways to produce thin fibers or very intricate parts. Ex. Bottles or body of a car. Styrofoam and urethane Ex. Bottles or body of a car. Styrofoam and urethane Identification Tests Identification Tests Melting point, burning properties, solubility, relative density, etc.Melting point, burning properties, solubility, relative density, etc. Elasticity and flexibilityElasticity and flexibility

Forms of Plastics Extrusion Extrusion Customarily designed to make a variety of objects (ex. straws, molding, hose and tubing, vinyl siding)Customarily designed to make a variety of objects (ex. straws, molding, hose and tubing, vinyl siding) Sheeting Sheeting Rollers produce sheets to a desired thickness (ex. food packaging)Rollers produce sheets to a desired thickness (ex. food packaging) Fibers and Filaments Fibers and Filaments Create synthetic fibers that resemble natural fibersCreate synthetic fibers that resemble natural fibers Molded Molded Forced under pressured into a closed moldForced under pressured into a closed mold Blow molding Blow molding Air forces material against walls of a mold (ex. two-liter soft drink bottles)Air forces material against walls of a mold (ex. two-liter soft drink bottles) Rotational molding Rotational molding Powered plastic is placed into a mold and is heated and rotatedPowered plastic is placed into a mold and is heated and rotated Adhesives Adhesives Bond materials togetherBond materials together

Did You Know? It would take seven truckloads of paper bags to deliver the equivalent of one truckload of plastic bags -- the fact that plastic is lightweight helps lower transportation costs and conserve natural resources. It would take seven truckloads of paper bags to deliver the equivalent of one truckload of plastic bags -- the fact that plastic is lightweight helps lower transportation costs and conserve natural resources.

Common Plastic Resins Used in Packaging Polyethylene Terephthalate (PET or PETE): Polyethylene Terephthalate (PET or PETE): Qualities: Clarity, strength/toughness, barrier to gas, resistance to grease/oil, stiffness, resistance to heat.Qualities: Clarity, strength/toughness, barrier to gas, resistance to grease/oil, stiffness, resistance to heat. Uses: Plastic soft drink bottles, mouthwash bottles, peanut butter and salad dressing containers.Uses: Plastic soft drink bottles, mouthwash bottles, peanut butter and salad dressing containers. Recycled Products: Tote bags, dishwashing liquid containers, clamshells, laser toner cartridges, picnic tables, hiking boots, lumber, mailbox posts, fencing, furniture, sweatshirts.Recycled Products: Tote bags, dishwashing liquid containers, clamshells, laser toner cartridges, picnic tables, hiking boots, lumber, mailbox posts, fencing, furniture, sweatshirts.

Common Plastic Resins Used in Packaging High Density Polyethylene (HDPE): High Density Polyethylene (HDPE): Qualities: Stiffness, strength/toughness, low cost, ease of forming, resistance to chemicals, permeability to gas, ease of processing.Qualities: Stiffness, strength/toughness, low cost, ease of forming, resistance to chemicals, permeability to gas, ease of processing. Uses: Milk, water and juice containers, grocery bags, toys, liquid detergent bottles.Uses: Milk, water and juice containers, grocery bags, toys, liquid detergent bottles. Recycled Products: Recycling bins, benches, bird feeders, retractable pens, clipboards, fly swatters, dog houses, vitamin bottles, floor tile, liquid laundry detergent containers.Recycled Products: Recycling bins, benches, bird feeders, retractable pens, clipboards, fly swatters, dog houses, vitamin bottles, floor tile, liquid laundry detergent containers.

Common Plastic Resins Used in Packaging Vinyl (Polyvinyl Chloride or PVC): Vinyl (Polyvinyl Chloride or PVC): Qualities: Versatility, ease of blending, strength/toughness, resistance to grease/oil, resistance to chemicals, clarity, low cost.Qualities: Versatility, ease of blending, strength/toughness, resistance to grease/oil, resistance to chemicals, clarity, low cost. Uses: Clear food packaging, shampoo bottles.Uses: Clear food packaging, shampoo bottles. Recycled Products: Air bubble cushioning, flying discs, decking, film, paneling, recycling containers, roadway gutters, snowplow deflectors, playground equipment.Recycled Products: Air bubble cushioning, flying discs, decking, film, paneling, recycling containers, roadway gutters, snowplow deflectors, playground equipment.

Common Plastic Resins Used in Packaging Low Density Polyethylene (LDPE): Low Density Polyethylene (LDPE): Qualities: Ease of processing, barrier to moisture, strength/toughness, flexibility, ease of sealing, low cost.Qualities: Ease of processing, barrier to moisture, strength/toughness, flexibility, ease of sealing, low cost. Uses: Bread bags, frozen food bags, grocery bags.Uses: Bread bags, frozen food bags, grocery bags. Recycled Products: Shipping envelopes, garbage can liners, floor tile, furniture, film, compost bins, paneling, trash cans, landscape timber, mud flaps.Recycled Products: Shipping envelopes, garbage can liners, floor tile, furniture, film, compost bins, paneling, trash cans, landscape timber, mud flaps.

Common Plastic Resins Used in Packaging Polypropylene (PP): Polypropylene (PP): Qualities: Strength/toughness, resistance to chemicals, resistance to heat, barrier to moisture, low cost, versatility, ease of processing, resistance to grease/oil.Qualities: Strength/toughness, resistance to chemicals, resistance to heat, barrier to moisture, low cost, versatility, ease of processing, resistance to grease/oil. Uses: Ketchup bottles, yogurt containers and margarine tubs, medicine bottles.Uses: Ketchup bottles, yogurt containers and margarine tubs, medicine bottles. Recycled Products: Signal lights, battery cables, brooms and brushes, ice scrapers, oil funnels, landscape borders, bicycle racks.Recycled Products: Signal lights, battery cables, brooms and brushes, ice scrapers, oil funnels, landscape borders, bicycle racks.

Common Plastic Resins Used in Packaging Polystyrene (PS): Polystyrene (PS): Qualities: Versatility, insulation, ease of processing, low cost, clarity.Qualities: Versatility, insulation, ease of processing, low cost, clarity. Uses: Videocassette cases, compact disc jackets, coffee cups, knives, spoons and forks, cafeteria trays, grocery store meat trays and fast- food sandwich containers.Uses: Videocassette cases, compact disc jackets, coffee cups, knives, spoons and forks, cafeteria trays, grocery store meat trays and fast- food sandwich containers. Recycled Products: Thermometers, light switch plates, insulation, egg cartons, vents, desk trays, rulers, license plate frames, concrete.Recycled Products: Thermometers, light switch plates, insulation, egg cartons, vents, desk trays, rulers, license plate frames, concrete.

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Review Key Questions What is a Polymer? What is a Polymer? What does a polymer look like on the molecular level? What does a polymer look like on the molecular level? What are the characteristics of polymers? What are the characteristics of polymers?

Lab Complete the Polymer Lab. Complete the Polymer Lab.

Mini-Project Complete the “Are Plastics Dangerous” project? Complete the “Are Plastics Dangerous” project?