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Delve into the diverse world of polymers - from large chainlike molecules like plastics to addition and condensation polymers like Polyethylene and PETE. Explore uses, recycling codes, and the timeline of plastics innovation.
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Polymers • Polymer- large chainlike molecule formed by the covalent bonding of smaller molecules called monomers • examples are plastics
Addition Polymers • An addition polymer forms when unsaturated monomers react to form a polymer • ethene will form polyethylene, shown on page 256 • polyethylene is easy to clean, chemically resistant- milk bottles, plastic wrap, dishes
Addition Polymers • Polypropylene is a stiffer polymer, used in utensils and containers • Polystyrene is formed from styrene (phenylethene), and is a poor heat conductor (styrofoam – Dow Chemical) • molded coffee cups and picnic coolers, insulates homes • Polyvinyl chloride (PVC) used for pipes in plumbing
Addition Polymers • Polytetrafluoroethene (PTFE, or “Teflon”) is very resistant to heat and chemical corrosion • found on nonstick cookware; coating on bearings and bushings used in chemical reactors
Condensation Polymers • Condensation polymers are formed by the head-to-tail joining of monomer units • usually accompanied by the lossof water from the reacting monomers, and forming water as a product
Condensation Polymers • Ex: polyethylene terephthalate (PETE) • Dacron, Fortrel, Polyesters: permanent press clothing, tire cords • Sheets of polyester called Mylar, used as magnetic tape in tape recorders and computers, as well as balloons • Nylon: carpet, fishing line, hosiery
Condensation Polymers • Examples: • aromatic rings form Nomex, which is a poor electrical conductor; makes parts for electrical fixtures; flame resistant clothing for race car drivers; flame resistant building materials • Kevlar: strong and flame resistant
CODE MATERIAL PERCENT OF TOTAL Polyethylene Terephthalate (PETE) 20-30 percent High Density Polyethylene 50-60 percent Polyvinyl Chloride (PVC) 5-10 percent Low Density Polyethylene 5-10 percent Polypropylene 5-10 percent Polystyrene 5-10 percent All other resins 5-10 percent Plastic container code system.
What Do the Numbers Mean? • 1 -- PETE (Polyethylene terephthalate) • PET is used in the production of soft drink bottles, peanut butter jars... • PET can be recycled into fiberfill for sleeping bags, carpet fibers, rope, pillows...
What Do the Numbers Mean? • 2 -- HDPE (High-density polyethylene) • HDPE is found in milk jugs, butter tubs, detergent bottles, motor oil bottles... • HDPE can be recycled into flower pots, trash cans, traffic barrier cones, detergent bottles...
What Do the Numbers Mean? • 3 -- V (Polyvinyl chloride) • PVC is used in shampoo bottles, cooking oil bottles, fast food service items... • PVC can be recycled into drainage and irrigation pipes...
What Do the Numbers Mean? • 4 -- LDPE (Low-density polyethylene) • LDPE is found in grocery bags, bread bags, shrink wrap, margarine tub tops... • LDPE can be recycled into new grocery bags...
What Do the Numbers Mean? • 5 -- PP (Polypropylene) • PP is used in most yogurt containers, straws, pancake syrup bottles, bottle caps.... • PP can be recycled into plastic lumber, car battery cases, manhole steps...
What Do the Numbers Mean? • 6 -- PS (Polystyrene) • PS is found in disposable hot cups, packaging materials (peanuts), and meat trays... • PS can be recycled into plastic lumber, cassette tape boxes, flower pots...
What Do the Numbers Mean? • 7 -- Other • This is usually a mixture of various plastics, like squeeze ketchup bottles, "microwaveable" dishes...
Timeline of Plastics 1862 – First man-made plastic 1866 – Celluloid makes it’s debut 1891 – Rayon is discovered 1907 – Bakelite is invented 1913 – Cellophane causes the plastics craze
Timeline of Plastics 1926 – PVC is invented 1933 – Polyethylene is discovered 1933 – Saran makes it’s debut 1938 – Teflon is discovered 1939 – Nylon stockings hit market 1957 – Here comes velcro