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Polyvinyl Chloride. By Annalisa McClure and Catherine Carey. Discovery : Serendipity. When: 1835 – Henri Victory Regnault, and again in 1872 – Eugen Baumann. Discovery : Serendipity.
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Polyvinyl Chloride • By Annalisa McClure and • Catherine Carey
Discovery : Serendipity • When: 1835 – Henri Victory Regnault, • and again in 1872 – Eugen Baumann
Discovery : Serendipity • In both cases, the polymer formed itself as a white solid inside flasks of vinyl chloride exposed to sunlight
Making use of it • - no attempt to develop a product with it till early the next century. – • -- proved to be too rigid and brittle
The blessing and the bane: • The blessing: plasticizers • 1926 -- Waldo Semon created the process of adding them. • Plasticizers make PVC flexible and easy to process. • 3 millions tons/year in 1965, 20 million tons/year now. • Pvc is one-fifth of all plastics
The blessing and the bane: The blessing: Quality of life
The blessing and the bane: • The bane: • 1. Plasticizers, • 2. Dioxin, • 3. Recyling difficulty
The blessing and the bane: • The bane: • 1. Plasticizers (phthalates) • They leach out of the plastic
The blessing and the bane: • The bane: 1. Plasticizers (phthalates) • Now found globally in rain water, soil, food, and in humans and wildlife • 90 percent of all phthalates are used in vinyl products • Animal studies: Damages sexual development in young rats, causes liver tumors • In humans: Impairs male reproductive system development in human infants and toddlers
The blessing and the bane: • The bane: 2. Very difficult to recycle: • Lifespan of 30 years or more, so natural breakdown is almost nil • Only 3% in EU by mechanical breakdown; estimated max of 9% by 2010 or 2020. • Pvc mixed in with other plastics makes the others more difficult to recycle.
The blessing and the bane: • The bane : 3. Dioxin • - Incineration produces carcinogenic dioxin, and doesn’t decrease the volume to be disposed of.
The blessing and the bane: Wonder why dioxins are formed in incinerators? Trace the chlorine! • Chlorine in = dioxin out
PVC-free alternatives exist!Many used in Sidney Olympics 2000
PVC-free business initiatives Wavin: No. 1 PVC pipe producer in Europe
Biobased Plastics • Material production now esclating with Cargill/Dow facility capacity of 300 million pounds per year PLA (polylactic acid) for NatureWorks fabrics and plastic.
Blue Man GroupWho?What does this have to do with PVC?Instruments
Starting material • Ethyne + HCL=PVC • Polymers formed from ethylene or substituted ethylenes are called vinyl polymers • No catalyst found
MONOMER, • REPEATING UNIT, • NAME, • USES
Mechanism of polymerization • Segment of PVC containing 3 units of vinyl chloride, initiated by hydrogen peroxide (Radical Initiator here) • Radical polymerization (also undergoes Anionic) • Initiator breaks homolytically into radicals • 3 steps • initiation • propagation • termination
Polymer looks like this…. • Branching vs. Unbranching
Added for flexibility • Products such as raincoats, shower curtains, and garden hoses • “New car smell” • Health and Safety