Mold Design Basics of Polymers PDF

06.11.2024 Basics of Polymers 1 Global & European Plastic Production World Plastics Production European Plastics Production 380...

06.11.2024 Basics of Polymers 1 Global & European Plastic Production World Plastics Production European Plastics Production 380 66 370 64 Plastics Productionn [Mt] Plastics Production [Mt] 62 360 60 350 58 340 56 330 54 320 52 310 50 2016 2017 2018 2019 2020 2016 2017 2018 2019 2020 Year Year Figures do not include the production of recycled plastics Figures do not include the production of recycled plastics Mould Design/WS 2024/2025. Michael Kaisser. Source: Plasticseurope Page: 2 06.11.2024 2 1  06.11.2024 European Plastic Demand (2020) Total: 49.1 Mt Source: Plasticseurope Mould Design/WS 2024/2025. Michael Kaisser. Page: 3 06.11.2024 3 Distribution by Resin Type (2020) Total: 49.1 Mt Source: Plasticseurope Mould Design/WS 2024/2025. Michael Kaisser. Page: 4 06.11.2024 4 2  06.11.2024 From Cruel Oil to Plastic Source: British Plastics Federation Mould Design/WS 2024/2025. Michael Kaisser. Page: 5 06.11.2024 5 From Monomer to Polymer Polymers are large molecules made up of repeating units called monomers Monomer Break double bond Add molecules togehter at high temperature & pressure Mould Design/WS 2024/2025. Michael Kaisser. Page: 6 06.11.2024 6 3  06.11.2024 Polymer Chain Structure A polymer prepared from a e.g.: PP, PE, PVC,…. single monomer is a homopolymer PA’s: PA6, PA12… —A—A—A—A—A— If two or more monomers are e.g.: PBT, PET,…. employed, the product is a copolymer PA’s: PA6I/6T, PA12/6/66… —A—B—A—B—A—B—A— Alternate copolymer —A—A—B—A—B—A—B—A— Random copolymer Mould Design/WS 2024/2025. Michael Kaisser. Page: 7 06.11.2024 7 Molecular Weight Distribution Increasing molecular weight: Mass fraction A B Increase: Tensile strength impact strength Decrease: Flow (Viscosity) ability of crystallisation Molecular Weight Molecular Weight (Mw): Polymer A with higher Mw: higher viscosity Polymer B with lower Mw: lower viscosity Measurement with Gel Permeation Chromatography (GPC) Mould Design/WS 2024/2025. Michael Kaisser. Page: 8 06.11.2024 8 4  06.11.2024 Polymer Synthesis Polysynthesis Polycondensation Polyaddition Polymerisation PA Polyurethane (PUR) Polyethylene (PE) Phenolic resins (PF) PUR foams Polypropylene (PP) Polyurea (UF) Epoxy resins (EP) Polyvinylchloride (PVC) Sideproduct Mould Design/WS 2024/2025. Michael Kaisser. Page: 9 06.11.2024 9 Polymer Synthesis O H2 H2 O H2 N C H2 N C C C R OH C C C OH H2 H2 H2 Amino-acid Amino-capronic-acid = 6 C atoms O O O O H N C 5 C N C C N C 5 C N C 5 C n NH H2 H2 5 H2 H2 H H H H Polyamide 6 Mould Design/WS 2024/2025. Michael Kaisser. Page: 10 06.11.2024 10 5  06.11.2024 Polymer Synthesis O O R' H2N NH2 C C HO R OH Diamine H2O Dicarbonic-acid H2 H2 H2 O H2 H2 C C C NH2 C C C OH H2N C C C HO C C C H2 H2 H2 H2 H2 Hexamethylen- O Adipic acid diamine = 6 C atoms = 6 C atoms O O O O HO C C C N C N C C 4 C N C N nH 4 6 6 H2 H2 H2 H2 H H H H Mould Design/WS 2024/2025. Michael Kaisser. Polyamide 66 Page: 11 06.11.2024 11 Aliphatic, partially aromatic & aromatic Thermoplastics Example: H O Aliphatic: Polyamide N OH H N traditional polyamides: H O n PA66, PA6, PA12, PA610 Partially aromatic: H O H N N One aromatic monomer: H OH PAMXD6, polyarylamide-PAA PA6I, PA6I/6T, PA6T/66, O n polyphthalamide-PPA Aromatic: O OH H All monomers aromatic: N N O polyaramide, Kevlar, Twaron H H n Poly-p-phenylenterephthalamide, PPTA Mould Design/WS 2024/2025. Michael Kaisser. Page: 12 06.11.2024 12 6  06.11.2024 Aliphatic, partially aromatic & aromatic PA H H H H2 H2 H2 H C C C N OH N C C C C C H2 H2 H2 H O O n H H Higher glass-transition & melting temperature Higher stiffness & strengh at elevated temperatures Low creeping also at elevated temperatures Benzene: rotation of the C-C-bonds not Slower & lower penetration of moisture & other chemicals possible Lower influence of moisture on mechanical properties voluminous reduces movability of the polymer chains Better dimensional stability Increased chemical and hydrolysis resistance Mould Design/WS 2024/2025. Michael Kaisser. Page: 13 06.11.2024 13 Moisture Absorption H H O N N O H H H N Swelling O O O O H H H H H H O O H N O N N O H H Penetration of moisture / water molecules Mould Design/WS 2024/2025. Michael Kaisser. Page: 14 06.11.2024 14 7  06.11.2024 Hydrolysis Amide O O R C R H H N C R N + O R H H O H H Amine Acid Water Hydrolysis = chemical splitting of the amide-bond = irreversible reduction of the polymer chain length Mould Design/WS 2024/2025. Michael Kaisser. Page: 15 06.11.2024 15 Classification of Polymers Polymers Thermoset Elastomer Thermoplastic Thermoplastic elastomer (TPE) amorphous partially crystalline close meshed wide-meshed linear chain molecules cross-linked network of molecules PE – Polyethylene PUR – Polyurethan NR – Natural Rubber PP – Polypropylene EP – Epoxy Resin IR – Isoprene Rubber PA – Polyamides Mould Design/WS 2024/2025. Michael Kaisser. Page: 16 06.11.2024 16 8  06.11.2024 Classification of Polymers Classification of Polymers THERMOPLASTIC ELASTOMER THERMOSET linear chain molecules Wide-meshed network Close-meshed network - can melt of molecules of molecules - can be welded - can’t be melted - can’t be melted - warm deformable - can’t be welded - can’t be welded - recyclable - not recyclable - not recyclable - soluble in specific - insoluble - insoluble solvents - can swell - no swelling unloaded stretched THERMOPLASTIC ELASTOMER Mould Design/WS 2024/2025. Michael Kaisser. Page: 17 06.11.2024 17 Morphology of Thermoplastics Morphology of Thermoplastics Amorphous Semi Crystalline Physical cross-links crystalline soft amorphous hard glass clear (uncolored) opaque opaque - PMMA, PC, ABS - PA, PBT, POM, PET - TPE’s Mould Design/WS 2024/2025. Michael Kaisser. Page: 18 06.11.2024 18 9  06.11.2024 Mechanical Characteristics of Polymers  Strength: resistance of a material to external stress  Stiffness: resistance of a material to deformation  Hardness: resistance of a material to deformation under concentrated compressive load  Toughness: energy absorption capacity of a material during impacts Mould Design/WS 2024/2025. Michael Kaisser. Page: 19 06.11.2024 19 Amorphous & Crystalline Crystalline Amorphous hard, rigid, random shape bonded, ordered domains frozen amorphous polymer partially crystalline polymer Transparent or translucent Opaque or translucent + Good dimensional stability + High fatigue strength + Less creep + Good chemical resistance + Less warpage + Hard & tough - Brittle + Wear resistant - Less chemical resistance - Higher shrinkage & warpage - Stress crack sensitive Mould Design/WS 2024/2025. Michael Kaisser. Page: 20 06.11.2024 20 10  06.11.2024 Transition Temperatures: Semi Crystalline Glass Soft Processing Degradation Property Hard, Rigid Elastic Plastic - Usage Temperature Processing - Procesing Window Tg Glass transition Temp.: for most semi High Stiffness crystalline thermoplastics