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CHM 585 / 490. Chapter 5. Chapter 5. Polystyrene PET Addition polymerization Condensation Polymerization. Polystyrene. How many “mers”. Monomer Dimer Trimer Oligomer Polymer. Polystyrene. Polystyrene. Dow polystyrene plants. Polystyrene is a vinyl polymer
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CHM 585 / 490 Chapter 5
Chapter 5 • Polystyrene • PET • Addition polymerization • Condensation Polymerization
How many “mers” • Monomer • Dimer • Trimer • Oligomer • Polymer
Polystyrene is a vinyl polymer • made from vinyl monomers; that is, small molecules containing carbon-carbon double bonds. • simplest vinyl polymer, polyethylene is made from ethylene
Addition Polymerization • Addition polymerization if the entire monomer molecule becomes part of the polymer. • Polystyrene is made by an addition polymerization • Similarly polyethylene, polypropylene, and other vinyl polymers are addition polymers
PET by Transesterification • DMT is a distillable material • Can be purified • Melts at 140 C • Can be shipped and transferred as a liquid
Catalysis • Esterifications and transesterifications are acid catalyzed reactions. • But!!!!! • What else is an acid catalyzed reaction?
Ether Formation • Acid catalyzed dehydration of alcohols
PET catalysts • Typically not: • H2SO4, H3PO4 • Common catalysts: • Zinc acetate, Sb2O3, Ti(OR)4 • Often combinations used • Leave in catalyst