1 Step polymerization, curing, Material knowledge Introduction Linear polymers  Characteristics  Reactions  Kinetics  Stoichiometry Curing Material knowledge  Thermoplasts  Crosslinked resins  Elastomers

2 Step polymerization Types  Polycondensation  Polyaddition Polycondensation  Homo-polycondenzation  Hetero-polycondenzation - PA, PET, PC - PU

3 Step polymerization – structure, characteristics Structure Characteristics  Polycondenzation or addition of bifunction monomers  Assumption: the reactivity of active groups does not change during polymerization  Conditions: equimolar stoichiometry, large conversion

4 Step polymerization - characteristics Conversion, and polymerization degree Carothers equation Conversion Pol. Degr. (%) x n PA molecular mass: x n = 106 – 116 p > 99 %

5 Step polymerization – run Stepwise growth, polymers can be only produced at high conversion x n = 1 p = 0 x n = 1,3 p = 0,25 x n = 2 p = 0.50 x n = 4 p = 0.75

6 Step polymerization - kinetics Auto catalysis Acid catalysis Assumption: the reactivity of function groups is independent of the chain length

7 Step polymerization – kinetics The assumption is true

8 Step polymerization – stoichiometry and molecular mass Disparity in equimolar ratio  Introduction, purity  Probability of reaction between two function groups  Secondary reaction  Goal Consequences  Decreased molecular mass  Given end group Complete conversion No. of molecules No. of end groups No. of polymers Polymerization degree

9 Step polymerization – stoichiometry and molecular mass Partial conversion rp (%)x n 1 99, ,952 99,939

10 Polycondenzation – in practice Equilibrium reactions Reaction types  K < 4 – polyester, the evaporation of secondary product is necessary  K is large – phenolic resin (secondary product does not influence the reaction

11 Polycondenzation – in practice In practice – dehydration of salts Interface polycondenzation Ring containing derivatives C3,4 – polymerization, C5,6 – cyclization

Polycondenzation – in practice 12

13 Step polymerization – typical reactions

14 Step polymerization - comparison Chain polymerizationStep polymerization Only monomers can add to the growing chain Any molecule in the system can react Concentration of monomer is decreasing during polymerization Monomer runs out at the beginning of polymerization (C x=10 = 1 %) The large molecules form immediately after the beginning of the polymerization and the molecular mass is constant during polymerization The molecular mass of the polymer is growing during polymerization The amount of product is increasing with time, but molecular mass is constant High conversion is needed for large molecular mass Only monomers, polymer molecules and % active sites are present The distribution of components with different molecular masses can be calculated as a function of time

15 Curing – conditions, characteristics Precondition  Bifunction monomer  linear  Polyfunction monomer  crosslinked Components  Gel: non soluble  Sol: soluble Average functionality Conversion, x n f av p (%) x n ,

16 Curing – gelation, practical aspects Gelation Processing Application  Bakelite, aminoplast  Polyester  Epoxy resin  Polyurethane

17 Material knowledge - thermoplasts Polyethylene (PE)  Monomer CH 2 =CH 2  Polymerization Gas phase, coordination  Chain structure Branched (LDPE) Linear (HDPE) Copolymer LLDPE  Structure Crystalline (T m °C)  Processing Extrusion, blowing, injection molding  Application Packaging, pipe, household tools Polypropylene (PP)  Monomer CH 2 =CHCH 3  Polymerization Stereospecific  Chain structure Isotactic Syndiotactic Atactic  Structure Crystalline (T m 165 °C)  Processing Extrusion, blowing, injection molding  Application Packaging, pipe, household tools, automotive, fiber, textile

18 Material knowledge - thermoplasts Polytsyrene (PS)  Monomer CH 2 =CHC 6 H 5  Polymerization Radical, (ionic)  Chain structure Atactic (Isotactic)  Structure Amorphous (T g 100 °C)  Processing Extrusion, injection molding  Application Sheet, Packaging, automotive parts, optical parts, instrument parts Poly(vinyl-chloride) (PVC)  Monomer CH 2 =CHCl  Polymerization Radical: suspension, emulsion, bulk  Chain structure Atactic  Structure Amorphous (T g 80 °C)  Processing Extrusion, injection molding, calendering  Application Building industry (pipe, floor, window), synthetic leather, medical  Other - environmental

19 Material knowledge - thermoplasts Polyamide (PA)  Monomer Variable (diacids and diamines)  Characteristic group (-CO-NH-)  Types (PA6; 6,6; 6,10; 11)  Polymerization Polycondezation, ionic  Chain structure Linear  Structure Crystalline (T m °C)  Processing Extrusion, injection molding, fiber, mechanical  Application Instruments, clothing, coatings  Modification Fiber reinforcement, blends Polycarbonate (PC)  Monomer – dian and phosgene C 6 H 5 -C(CH 3 ) 2 -C 6 H 5 -OCOO  Polymerization Polycondenzation  Chain structure Linear  Structure Microcrystalline (T m 220 °C)  Processing Extrusion, injection molding  Application Instrument and machine industry, optical lenses, packaging, automotive  Modification Blends

20 Material knowledge - thermoplasts Linear polyester (PET)  Monomer Dimethyl-phtalate Ethylene-glycol  Polymerization Step polymerization (transesterification)  Chain structure Linear  Structure Crystalline (T m 265 °C)  Processing Extrusion, injection blow molding  Application Packaging, machine and instrument industry  Modification Fiber reinforcement, blends Poly(methyl-methacrylate) (PMMA)  Monomer CH 2 =CCH 3 COOCH 3  Polymerization Radical, (bulk)  Chain structure Linear  Structure Amorphous (T g 105 °C)  Processing Extrusion, injection molding, mechanical  Application Optical parts, synthetic glass

21 Material knowwledge – crosslinked resins Phenol-formaldehyde resins  Components Phenol, formaldehyde  Types Novolak, rezol  Chain structure Novolak - linear Resol - crosslinked  Crosslinking Temperature, formaldehyde  Application Wood industry, electric tools, aircraft parts  Advantage Good mechanical properties, price  Drawback Color and smell Aminoplasts  Components Polyamine Formaldehyde  Crosslinking Temperature  Application Furniture  Advantages Good mechanical properties and color  Drawback Price

22 Material knowledge – crosslinked resins Unsaturated polyester resins  Components Unsaturated dicaroxylic acids or dicarboxylic anhydrides, diols, styrene,  Crosslinking Polycondenzation, radical  Modification Fiber reinforcement  Application Automotive industry, sport tools, barrels  Advantage Good mechanical properties, price  Drawback Smell, shrinkage Epoxy resins  Components Dian Epichlorohydrine  Crosslinking Polycondenzation  Modification Fiber reinforcement  Application Pouring resins, glues, composites, aircraft, military applications  Advantages Good mechanical properties  Drawback Price

23 Material knowledge – crosslinked polymers Polyurethanes  Components Diisocyanate – diol or polyether – polyester  Crosslinking Polyaddition  Application Foams (rigid and flexible), elastomers, glues, fibers, clothing, furniture, instrument industy  Advantage Variable structure and properties  Drawback Price Elastomers  Polyisoprene  Polybutadiene  Buthadiene-styrene copolymer  Polychloroprene  Nitril-rubber  EPR and EPDM