Polymeric Materials. Sunan Tiptipakorn, D.Eng.

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1 Polymeric Materials Sunan Tiptipakorn, D.Eng. Department of Chemistry, Faculty of Liberal Arts and Science, Kasetsart University, Kamphaen Saen Campus, Nakorn Phathom, Thailand.

2 Introduction Material Science Relationship Structure Processing Properties Performance

3 Materials Metals Polymers - organic polymers - inorganic polymers Composites Ceramics Semiconductors

4 Polymers

5 Thermoplastics - can be recycled Example:- PE, PP, PVC Ref.: Ref.: Thermosetting -can not be recycled Example:- polyurethane, epoxy - no melting temp. Ref.:

6 Organic Polymers

7 Main Organic Polymers 6 types of well known thermoplastics

8 Extruder

9 Polyethylene (PE) Ethylene monomer (Ethene) or polyethylene (polyethene) or Ref.: PE granules: (1)Natural form, (2) and (3) are colored with dyes

10 HDPE (High Density Polyethylene) Ref.: Ref.: high crystallinity (Linear PE) LDPE (Low Density Polyethylene) Low crystalinity (Branched PE) Ref.:

Branched Chains and Linear Chains Ref.:http://www.

11 Branched Chains and Linear Chains Ref.:

12 Free Radical Polymerization High Temp. High Pressure Examples:- LDPE PVC PS Ref.:

13 Coordination Polymerization Low Temperature Low Pressure Ziegler and Natta Catalyst icl 4 + Aluminium co-catalyst Examples: HDPE, PP Ref.:

14 Polypropylene (PP) Ref.: Ref.:

15 Three Types of Polypropylene Ref.:

16 Polystyrene (PS)

17 Types of Polystyrenes

18 Polyvinyl chloride Polymerization: Morphology: Glass transition temperature: free radical chain polymerization highly amorphous, ~11% crystallinity ~84 o C Ref.:

19 Polyethylene terephthalate (PET) Ref.:

20 Organic Polymers Benefits Low Cost / Affordability Electrical Insulation Abrasive Resistance Easiness to Process Light-weight Drawbacks - Low high Temp. - Swelling organic solvent - low range of Temp. - Low flame resistance - Not suitable for artificial organs

21 Inorganic Polymers

22 Methodology 1) Addition of Side Groups Addition polymerization of vinyl monomer H H Vinyl monomer H C C X Examples X = SiCH 3 ; OSiCH 3 ; C 6 H 5 PO Steric effect Free Radical Polymerization Coordination Polymerization

23 1) Addition of Side Groups (cont.) Vinyl monomer Copolymer with Styrene Methyl Methacrylate Acrylonitrile

24 2) Coordination polymerization of organometallic reagent with organic polymer (e - donor) Example M M = inorganic Coordination bonding

25 3) Synthesis via polymers with inorganic substance in main chain 3.1 Non-metallic inorganic substances (Si, P, S, O, N) 3.2 Transition metals Main chain Examples Poly(organosiloxane) or Silicone Phosphazene polymer Metallo-backbone polymer

26 Polyorganosiloxane (Silicone) Most commonly used : poly(dimethylsiloxane) CH 3 H 2 O (CH 3 ) 2 SiCl 2 -HCl hydrolysis dimethyldichlorosilane H 3 C H 3 C Si O O CH 3 Si CH 3 O Si O Si CH 3 CH 3 CH 3 octamethylcyclotetrasiloxane acid or base CH 3 O Si CH 3 n poly(dimethylsiloxane) (MW > 25,000) O 2 penetration: artificial organs

27 Phosphazene Polymer Conductive Polymer Raw Materials: PCl 5 + NH 4 Cl R N P R n n> Ring-opening polymerization Macromoleular substitution reaction Direct condensation

28 Phosphazene Polymer (cont.) R changes R N P R n n> Properties changes Cl - Inorganic rubber - Organic solvent swelling - Reacted with water OCH 2 CF 3 - water resistant Applications: Dyes, gasket, O-ring, and etc.

29 Natural Inorganic Polymers

30 Characteristics Natural Inorganic Polymers Three dimensional structure Rigid and Brittle Silica glass Ref.: Asbestos Silicate Ref.: Ref.:

31 Silicic acid HO Condensation O- Si OH -4H 2 O Na+ OH Polysilicate Tetrahedral structure Ref.:

32 Most well known polysilicate : Silica (SiO 2 ) Crystalline: Quatz Tridymite Cristobalite Amorphous

33 Molecular Alignments of Tetrahedral Molecules in Various Patterns of (SiO 4 ) 4-

34 (SiO 4 ) 4- and (AlO 4 ) 5- Polysilicate aliminate Zeolite Tetrahedral Crystalline aluminosilicate To Soften water; act as catalyst in petrochemical plants

35 Basic Zeolite Structure Ref.: Legend: Circle = Oxygen, Square = Silicon, aluminium Tetrahedral Ref.:

36 Ionomer Main chain: Hydrocarbon or Fluorocarbon Side chain: Carboxylic or sulfonic group Na + Ref.:

37 Ref.:

38 Applications of Ionomers Golf ball Primer Coating

39 Ceramics

structure High strength and modulus High

40 Ceramics Compounds of Silicates Oxides Carbides Nitrides Aluminates Ref.: Strong covalent bond with network structure High strength and modulus High thermal Resistance Brittle Ref.: Ref.:

41 Manufacturing Steps Milling to micron scale High Temperature and High Pressure Ref.: Ref.:

42 Sol-gel Process 1. Mixing metal with alcohol to form metal alkoxide Ti + C 2 H 5 OH Ti(OCH 2 CH 3 ) (s) + 2H 2 2. Dissolving metal alkoxide and mixing with water Ti(OCH 2 CH 3 ) (solution) + 4H 2 O Ti(OH) 4(s) +4C 2 H 5 OH Ti + H 2 O Complex of Titanium Oxide and hydroxide 3. Dehydrating Ti(OH) 4 with acid or base Three dimensional network..gel 4. Burning o C

43 Ceramic Composites Ceramics + Additives Increase Toughness Cutting machine, Grinding wheel Ceramic Fiber of SiC or carborundum Polydimthyl silane 400 o C Ceramic Fiber o C to remove H 2 and C atom

Ceramics Alumina: Circuit Board SiC: Abrasive resistant

uk/cleaner/Electronics_Projects/Handbook_2.

htm Quartz: piezoelectric Ref.: http://www.britannica.

44 Ceramics Alumina: Circuit Board SiC: Abrasive resistant materials Ref.: Quartz: piezoelectric Ref.: La-Ba-Cu:Superconducting Ceramic

45 Piezoelectricity is the ability of some materials to generate an electric field or electrical potential in response to applied mechanical stress. Ref.:

46 Reinforcing Elements Pure Resin Glass Fiber Cellulose Fiber Carbon Fiber Aramid Fiber or Kevlar

47 Carbon Fiber Most commonly used Acrylic Fiber: Polyacrylonitrile Step o C

48 Step 2

49 Step 3

50 Step 4

51 Thermoplastic Elastomer

52 Thermoplastic Elastomer Copolymer Behaviors: Melt when heating (Thermoplastics) Elastic (Elastomer) Example Butadiene + High Impact Polystyrene PS Butadiene PS Ref.:

SBS Rubber http://pslc.ws/macrog/kidsmac/rubber.

53 SBS Rubber Polystyrene = tough hard plastic durability. Polybutadiene = rubbery material rubber-like properties.

54 References: 1. Schaffer J.P. et al., The Science and Design of Engineering Materials, R.D. Irwin Inc., Chicago, Allen S.M. and Thomas e.l., The structure of materails, The MIT Series in Materials Science and Engineering, John Wiley and Sons. Inc., New York, Allcock H.R. and Lampe F.W., Contemperary Polymer Chemistry, 2 nd Ed., Prentice Hall, New York, Jersey, 1990.

55 Thank you for your kind attention

Lecture No. (1) Introduction of Polymers

Lecture No. (1) Introduction of Polymers Polymer Structure Polymers are found in nature as proteins, cellulose, silk or synthesized like polyethylene, polystyrene and nylon. Some natural polymers can also