Chapter 16 Polymeric Materials

1. Chapter 16Polymeric Materials • Monomers and Polymers • Linear and Branched Polymers • Types of Polymerization • Addition Polymerization • Condensation Polymers • Extensively Cross-Linked Polymers (SKIP) • Three-Dimensional Structure Polymers (SKIP p. 813-818 top)

2. Chapter 16Polymeric Materials • Polymer Nomenclature - Monomers and Polymers • Definitions of polymer, monomer, plastic, thermoplastic and thermoset plastic in “handout” • repeat units, average degree of polymerization • Polymer Architecture - Linear and Branched Polymers • See handout for depiction of linear, branched, star, comb, ladder and cross-linked networks • Polymer Morphology • ordered = crystalline regions • random = amorphous regions • Polymer properties and transitions • Modulus (degree of hardness/softness) • Glass Transition Temperature (transition from glassy to rubbery) • Melt Temperature(transition to viscous flow)

3. Chapter 16Polymeric Materials • Types of Polymerization • Addition (also called chain-growth) • Radical (three steps – initiation, propagation, termination) • Cationic • Anionic (called “ living” polymer, can make block co-polymers) • Condensation (also called step-growth) loss of water • Polyester • Polyamide • Polycarbonate • Polyurethane • Epoxy resins • Polysaccharides (starch) • Polypeptides and proteins

4. Chapter 16Polymeric Materials • Addition Polymerization • Radical Polymerization • 3 steps (initiation, propagation, and termination) see handout • Ionic Polymerization • cationic • anionic (living polymers, useful to make “block” co-polymers) • Cross-Linking in Polymers (can use bi-functional, tri functional, quadri-functional monomers) • Heteroatom-Containing Addition Polymers • Polyols • can not make polyvinyl alcohol from vinyl alcohol, instead polymerize vinyl acetate and then hydrolyze to polyvinylalcohol • Polyethers (e.g., poly(ethylene glycol) • Polyacetals (e.g., paraformaldehyde from formaldehyde)

5. Chapter 16Polymeric Materials • Condensation Polymers • Polyesters (from a dicarboxylic acid and diol) • Polysaccharides (from carbohydrate (or sugar) condensation) • Polyamides (from dicarboxylic acid and diamine) • Polypeptides (from20 common amino acids) • Polyurethanes (form bis-isocyanate and diol)

6. Chapter 16Polymeric Materials • Three-Dimensional Structure of Polymers • Polypropylene (SKIP pages 813-818 top) • Naturally Occurring Polypeptides • Primary structure - amino acid sequence • Secondary structure • -pleated - deviation from planarity due to steric interactions • -helix - hydrogen bonding from peptide units in the same chain • Tertiary structure - spatially dispersed -pleated and -helix • Quaternary structure - several polypeptides form a complex • Cellulose and Starch • Starch from -glucose (axial C1-OH group) • Cellulose from -glucose (equatorial C1-OH group)

7. Chapter 16Polymeric Materials • Review of Reactions • Be able to draw the basic polymerization mechanism for • radical, anionic, cationic • general condensation polymerization for a polyester, polyamide, polyurethane, polypeptide • Review Problems • Especially review problem 16.1 • Know nomenclature of synthetic and natural polymers • Know how to identify repeat units

8. Chapter 16Polymeric Materials • Summary • Definitions for polymer, monomer, plastic, thermoplastic, thermoset, melt temperature, glass transition temp. • Nomenclature for simple addition and condensation polymers • Linkages between monomers include • C-C bonds in vinyl polymers • C-O bonds in polyesters, polyacetals, polyethers, polysaccharides • C-N bonds in polyamides, polypeptides • Role of Hydrogen bonding in nitrogen and oxygen containing polymers • intermolecular H-bonding in  pleated peptides • intramolecular H-bonding in  helix peptide structures • primary, secondary, tertiary and quaternary structures