Polymers, plastics & macromolecules Plastic = Polymer + additives Processability: Mechanical properties: Other: Anti-oxidants Fillers Stabilizers Sulphur Weakeners - lubricants Colorants Fire retardants Blowing agents Nucleating agents Macromolecule = well-defined large molecule (dendrimers) and/or a very well-defined polymer (proteins) Materials gasses liquids solids ceramics polymers metals natural polymers synthetic polymers polypeptides polysacharides polynucleotides thermoplast thermoset Nature’s use of polymers: Polysacharides. Cellulose (wood, cotton) Starch (potatoes, corn) Chitin Polypeptides. (Spider) Silk Enzymes Collagen Horn Ivory Polynucleotides. DNA, RNA History of synthetic polymers Goodyear: Natural rubber - Used for over 3,500 years. Charles Goodyear Natural rubber 1839 1800 1900 2000 D S S S S S n History of synthetic polymers ONO2 ONO2 ONO2 ONO2 O2NO O O2NO O O O O O O O2NO O O2NO ONO2 ONO2 ONO2 ONO2 Natural rubber 1839 1800 1900 2000 Parkesine 1862 Parkes: Parkesine (based on cellulose nitrate) – first colorful plastic. Alexander Parkes History of synthetic polymers Cellulose based plastics (nitrate, acetate, xanthate) Charles Frederick Cross JohnEdward Wesley John Hyatt Bevan Cellulose acetate, Rayon Natural rubber 1892 1839 Celluloid 1868 1800 1900 2000 Parkesine 1862 ONO2 ONO2 O2CMe O2CMe ONO2 ONO2 O2NO O2CMe O O2NO O2CMe O MeCO2 O MeCO2 O O O O O O O O O O O2NO O O2NO O OMeCO2 O MeCO2 ONO2 ONO2 O2CMe O2CMe ONO2 ONO2 O O2CMe O2CMe History of synthetic polymers OH OH OH HO OH 'the material of a thousand uses' OH Cellulose acetate, Rayon Natural rubber 1892 1839 Celluloid 1868 1800 1900 2000 Parkesine Bakelite 1862 1907 Baekeland: Bakelite - First fully synthetic polymer. Leo Hendrick Baekeland History of synthetic polymers RignaultSemon: (1835),Baumannplasticized polyvinylchloride (1872), Klatte (1913) polyvinylchloride Henry Victor Rignault WaldoFriederich Semon Klatte Eugen Baumann Cellulose acetate, Rayon Natural rubber 1892 1839 Celluloid PVC 1868 1913 1800 1900 2000 PVC Parkesine PVC Bakelite Plasticized PVC 1835 1862 1872 1907 1926 O Cl Cl Cl Cl O O O Polystyrene - 1839: E. Simon - 1845: A.W. Hofmann, J.Blyth - 1912: I Ostromislenskii - 1922: Staudinger Cellulose acetate, Rayon Definition of Polystyrene Natural rubber 1892 polymers E. Simon 1839 Celluloid PVC 1839 Polystyrene 1868 1913 Hofmann & Blyth 1845 1800 1900 2000 Polystyrene production PVC Parkesine PVC Bakelite Plasticized PVC ~ 1935 1835 1862 1872 1907 1926 Staudinger: Plastics defined as a chain molecule wherein the monomeric blocks are linked together by covalent bonds. So called polymers (poly meros = many parts) Hermann Staudinger History of synthetic polymers Cl Cl Cl Cl D Cl Cl n Cl Cl Cl Cl Cellulose acetate, Rayon Definition of Polystyrene Natural rubber 1892 polymers Neoprene E. Simon 1839 Celluloid PVC 1839 Polystyrene 1868 1913 1931 Hofmann & Blyth 1845 1800 1900 2000 Polystyrene production PVC Parkesine PVC Bakelite Plasticized PVC ~ 1935 1835 1862 1872 1907 1926 Carothers: neoprene. Wallace Hume Carothers History of synthetic polymers Fawcett/Gibson: Low density polyethylene (LDPE). Rigenald Gibson Eric Fawcett Cellulose acetate, Rayon Definition of Polystyrene Natural rubber 1892 polymers Neoprene E. Simon 1839 Celluloid PVC 1839 Polystyrene 1868 1913 1931 Hofmann & Blyth LDPE 1845 1933 1800 1900 2000 Polystyrene production PVC Parkesine PVC Bakelite Plasticized PVC ~ 1935 1835 1862 1872 1907 1926 History of synthetic polymers O H O N N N H O H Cellulose acetate, Rayon Definition of Nylon 66 Polystyrene Natural rubber 1892 polymers 1935 Neoprene E. Simon 1839 Celluloid PVC 1839 Polystyrene 1868 1913 1931 Hofmann & Blyth LDPE 1845 1933 1800 1900 2000 Polystyrene production PVC Parkesine PVC Bakelite Plasticized PVC ~ 1935 1835 1862 1872 1907 1926 Carothers: nylon 66. Wallace Hume Carothers History of synthetic polymers Schlack: Nylon 6 – Perlon (IG-FarBen) Dickson & WhInfIeld: poly(ethylene terephtalate) Paul Schlack J.T. DIckson J.R. WhInfIeld Cellulose acetate, Rayon DefInItIon of Nylon 66 Polystyrene Natural ruBBer 1892 polymers 1935 Neoprene E. Simon 1839 CelluloId PVC 1839 Polystyrene 1868 1913 1931 Hofmann & Blyth LDPE 1845 1933 1800 1900 2000 1938- 1943 - PTFE Polystyrene - Polyurethanes productIon - Nylon 6 PVC ParkesIne PVC BakelIte PlastIcIzed PVC ~ 1935 - PET -SilIcones 1835 1862 1872 1907 1926 - ….. Bayer: Polyurethanes (IG-FarBen, Bayer) Plunkett: Teflon (Du Pont) Otto Bayer Roy J. Plunkett History of synthetic polymers Ziegler: High density polyethylene Karl Ziegler Cellulose acetate, Rayon Definition of Nylon 66 Polystyrene 1892 1935 Natural rubber polymers HDPE i-PP HDPE LLDPE E. Simon Celluloid PVC Neoprene 1839 1953 1954 Phillips Cat 1978 1839 Polystyrene 1868 1913 1931 Hofmann & Blyth LDPE 1958 1845 1933 1800 1900 2000 1938- 1943 - PTFE Polystyrene - Polyurethanes production - Nylon 6 PVC Parkesine PVC Bakelite Plasticized PVC ~ 1935 - PET -Silicones 1835 1862 1872 1907 1926 - ….. Natta: isotactic polypropylene Giulio Natta PMMA KevlarLLDPE Plexiglas Velcro Biodegradable Polymers Polycarbonate Fleece Spandex Semiconducting Polymers Lycra Classification of polymers Structure Thermal behavior Thermoplast Linear Branched Crosslinked OH Thermoset OH OH S HO OH S S S OH Classification of polymers Composition Polymerization method homo polymer Stepgrowth proces Polycondensation (PET, PC, nylon 66) block copolymer Alternating copolymer Chaingrowth process Radical polymerization (PVC, PS) cationic/anionic polymerization (polyisobutene, PAN) random copolymer Coordination polymerization (PE, PP) Ring opening polymerization (nylon 6, polylactides) graft copolymer Classification of polymers Chain atom configurations Poly(cis-1,4-isoprene), ‘natural rubber’ Poly(trans-1,4-isoprene), ‘gutta-percha’ Tacticity atactic isotactic syndiotactic Requirements for polymerization. ∆G = ∆GPolymer – ∆GMonomers S S S S S S S S S S S S ∆G = ∆H – T·∆S S S o T > 160 C Floor temperature ~ 160oC Mostly ∆H < 0 en ∆S < 0 ΔG‡ Only when ∆Go < 0 polymerization takes place. monomers And the activation energy shouldn’t be too high. ΔGo polymer Polymerization takes place only when T ·│∆S│ < │∆H│ When T ·│∆S│ = │∆H│ à Tc = ∆H/∆S is the ceiling temperature Above the ceiling temperature (T ·│∆S│ > │∆H│) depolymerization takes place. Ceiling temperature. K Mn-1 + M Mn K = [Mn] / [Mn-1] [M] ≈ 1/ [M] Equilibrium condition: ∆G = 0 ∆G = ∆Go + R·T·LnK = ∆Go + R·T·Ln(1/[M]) ∆Go = ∆Ho – T·∆So = R·T·Ln[M] o o Tc = ∆H / (∆S + R·ln[Mc]) Tc mostly given for [M] = 1 mol/L The ceiling temperature is dependent on the monomer concentration. Stepgrowth proces Mw - Polycondensation Characteristics: • all present molecules react with one another during the entire reaction • usually no termination • degree of polymerization increases in time 0 100% • usually a small molecule is split off monomer consumption O O O OH - n H O OH 2 + HO HO O O O n H O OH - n H2O O N + H2N NH2 HO O N O n H O O - n HCl OH + O O Cl Cl n O H O OH O C N N C O + HO N N O H O n Chaingrowth process Mw Radical polymerization (PVC, PS) cationic/anionic polymerization (polyisobutene, PAN) Coordination polymerization (PE, PP) Ring opening polymerization (nylon 6, polylactides) 0 100% monomer consumption R • R R• • n Characteristics: • no splitting off of small molecules • polymerization by addition of monomers to a growing chain • initiation required • several termination mechanisms • growth between initiation and termination only for a few seconds • degree of polymerization decreases in time Radical polymerization. O O O - CO2 Initiation. ½ • O O O • X X Propagation. R• • + • R X X n Termination. X X • R Combination of radicals 2 R R X X n n X X n H H • Disproportionation R + R R + R • X X X X X X X X n m n m Chain transfer To monomer X • X R + R + H • X X X X n n To polymer - intermolecularly X H X • n R + R R + R • R X X X H X X X X X X X n m n m m Leads to long chain branching • To polymer - intramolecularly • • CH2 CH2 CH CH3 CH CH3 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 Leads to short chain branching cationic polymerization + - - + - + H [MeOBF3] [ROBF3] [ROBF3] n anionic polymerization N N N N C C N C C C + - NH2 + - + - K K NH2 K NH2 n Coordination/insertion polymerization CH3 CH3 [Ti]-CH3 [Ti]-CH3 [Ti] [Ti] n O O P P [Pd] [Pd] C O O O O [Zn] P O O O [Zn] P O CO2 n O O O n Ring opening polymerization O O H H H+ N N Acid catalyzed H n O [Zn] OMe O O Metal catalyzed O (coordination polymerization) n O O O [Zn] OMe O O O O n O O O O [Al] OMe n Molecular weight and molecular weight distribution. n n = 10,000 n+1 In a polymer sample the chains hardly ever have the same length. They have an average length. Exceptions are for example proteins. Number average molecular weight. Number of chains with length i Ni Mole fraction ni = = Total number of chains ΣNi Σni = 1 ΣNi·Mi Ni M = = ·M = Σn ·M n Σ ( ) i i i ΣNi ΣNi Weight average molecular weight. Weight of chains with length i ni·Mi ni·Mi Weight fraction w = = = i Total weight of all chains Σni·Mi Mn Σwi = 1 2 Σni·Mi Mw = Σwi·Mi = Σni·Mi ΣNi·Mi Compare: Mn = Σni·Mi = ΣNi An example: City Population Amsterdam 1,000,000 Groningen 200,000 Schiermonnikoog 1,000 Average population: 1/3 x 1,000,000 Mn = Σni·Mi 1/3 x 200,000 1/3 x 1,000 = 400,333 We can say that the average person lives in a city of about 400,000. An example: Weighted average: This is an average that would account for the fact that a large city like Amsterdam holds a larger percentage of the total population of the three cities than Schiermonnikoog. City Population Amsterdam 1,000,000 Groningen 200,000 Schiermonnikoog 1,000 Mw = Σwi·Mi 1,000,000 1,000,000 x 1,201,000 = 1,000,000 x 0.8326 = 832,600 200,000 200,000 x = 200,000 x 0.1665 = 33,300 1,201,000 1,000 x 1,000 = 1,000 x 0.0008 = 0.8 1,201,000 + 865,900.8 We can say that the average person lives in a city of about 866,000.