Plastics by Béla Pukánszky Presented by Alfréd Menyhárd Department of Physical Chemistry and Materials Science, Laboratory of Plastics and Rubber Technology

2 Useful information Presentation  Oral lectures (Slides will be published on the net)  Recommended literature Gottfried W. Ehrenstein – Polymeric Materials Fred W. Billmeyer – Textbook of Polymer Science Laboratory practice Consultation Exam  Marks

3 Introduction Historical background Plastic industry Goal of the subject Important expressions and definitions  Macromolecule  Polymer  Polymerization  Structure Alignment  Application, processing  Plastics, modifications Differences between small molecules and macromolecules Syllabus

4 Structural materials Steep increasing Wide-range application Advantages  Good properties  Good price/performance ratio  Productivity Commodity polymers Unique behavior

5 History 1839 vulcanization of rubbers Goodyear 1870 celluloid Hyatt 1909 phenolic resin Bakeland 1915 synthetic rubber Leverkusen 1926 macromolecule Staudinger 1931 low density polyethylen ICI 1938 Nylon Carothers 1941 PET Whinfield 1954 PP Natta 1974 Kevlar Du Pont

6 Goals Introduction of the fundamental knowledge concern with plastics  Properties and behavior  Differences between plastics and traditional structural materials  Processing and characteristics  Applications and their requirements  Failure (breaking, tearing, etc.)  Plastics and the environment

7 Application of plastics According to application fields in 2000

8 Application of plastics According to their type

9 Definitions Macromolecule: large molecule consists of small constitutional repeating units linked by covalent bonds (n = ) Oligomer: few repeating unit linked by covalent bonds (n < 10) Repeating units: small building units of macromolecules Monomer: raw material of polymerization Polymer: cluster of macromolecules – organic, polymers, plastics, elastomers, resins

10 Polymers MonomerRepeating unit Traditional name Abbreviation polyethylenePE polypropylenePP polystyrenePS PVCPVC

11 Polymers MonomerRepeating unit Traditional name Abbreviation polytetrafluoroethylene PTFE poly(methyl-methacrylate) PMMA poly(ethylene-terephthalate) PET

12 Definitions Plastic: polymer containing additives and fillers Polymerization: process, which results in synthetic polymers Homopolymer: polymer containing one kind of repeating units Copolymer: polymer, which contains two or more kind of repeating units

Molecular structure Bonding of repeating units Assymetric monomers – head to tail structure Head to head and tail to tail structures Regularity and defects 13

Molecular structure Bonding of dienes 1-4 bonding 1-2 bonding 14

15 Molecular structure Configuration, izomerizm Cis-1,4-polybutadiene Trans-1,4-polybutadiene Asymmetric centers, tacticity

Molecular structure Stereospecific polymers Isotactic Syndiotactic Atactic 16

17 Molecular structure Chain-structure Structure of the chain  Linear  Short-chain branched  Long-chain branched  Crosslinked  Star-branched  Ladder  Network

18 Molecular structure Chain-structure TypeDensity Branches CrystallinityModulus (g/cm 3 )(CH3/1000 C)(%) (GPa) LDPE HDPE Change in structure results in considerable change in properties

19 Molecular structure Chain-structure, conformation Shape – conformation Distribution of conformational states Conformational changes Equilibrium shape: random coil (sphere) Size of the random coil  End-to-end distance  Radius of gyration  Size in solvents Hindering parameters

20 Molecular structure Characterization Polymerization degree: number of repeating units (x n ) Molar mass: x n · M Distribution of molar mass Number average molar mass (1) Mass or weight average molar mass (2, 3) Polydispersity (1) (2) (3)

21 Molecular structure Characterization Distribution of molar mass Average molar mass Determination  Number  Size  Volume  Viscosity Properties

22 Structure Polymer, plastic Polymer interactions  Physical – network  Secondary forces  Chemical – covalent crosslinking points Crosslinked polymers  Rubbers  Resins  Density of crosslinking points Structure  Amorphous, crystalline  Phase structure

23 Grouping Properties, characteristic temperatures Characteristic temperature  Elastomers  Thermoplasts  Thermosets  High performance plastics  Composites Properties  Stiffness, hardness  Impact resistance  Optical properties  Conductivity  Heat resistance  Unique properties

24 Plastics Additives and heterogeneous systems Additives  Stabilizing agents  Plasticizers  Pigments  Odor  Antistatic agents  Nucleating agents  Clarifiers  Acid scavengers  Flame retardants Heterogeneous systems  Polymers  Fillers  Organic polymers  Impact modifier  Fibers

25 Differences between polymers and small molecules Molar mass and its distribution Physical and phase state Conformation Low regularity, crystalline structure High viscosity Orientation Simultaneous deformation mechanisms Time-dependent properties

26 Plastics - Thematic Introduction Polymerization  Radical  Ionic polymerization  Polycondensation Physical part  Physics of macromolecules  Deformation and fracture Structure, properties  Crystalline and amorphous polymers  Heterogeneous systems Processing  Thermoplasts  Resins  Special techniques Application  Packaging  Public transport  Other Degradation and stabilization  Additives Plastics and the environment