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Thermoset Materials MFG 355.

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Presentation on theme: "Thermoset Materials MFG 355."— Presentation transcript:

1 Thermoset Materials MFG 355

2 Introduction Thermoplastics vs Thermosets Thermal properties Strength
Uses Processing

3 Viscosity and Thermal Control during Crosslinking

4 General Properties of Thermosets
Strength Flexibility Thermal Creep Ability to reinforce Ability to cure at room temperature

5 Formaldehyde Resins Phenolic Urea formaldehyde Melamine formaldehyde

6 Crosslinking Reactive Groups—Phenolics Formaldehyde Phenol Plus

7 Thermoset Types Phenolics

8 Crosslinking Reactive Groups—Amino plastics Formaldehyde Plus Amine

9 Amine plastics – clear adhesive

10 Crosslinking as Polymers are Formed
Three active sites Formaldehyde Melamine Plus

11 Crosslinking as Polymers are Formed
Melamine Formaldehyde Water

12 Thermoset Types Melamine Plastics

13 Crosslinking as Polymers are Formed
Water Melamine Formaldehyde

14 Polyester Thermosets (TS) or Unsaturated Polyesters (UP)
Largest group of thermosets Most like to be reinforced with fiberglass

15 Crosslinking Reactive Groups—Unsaturated polyesters Plus Carbon-carbon
Double bond Initiator (usually peroxide)

16 Thermoset Types Unsaturated Polyesters

17 Crosslinking Mechanism for Thermoset Polyesters
Styrene (large quantities) Peroxide

18 Crosslinking – Heat Peroxide breaks apart

19 Crosslinking – Approach of styrene

20 Crosslinking – bond to styrene
When styrene's double bond breaks, one end forms a free radical Half of peroxide bonds with other end of broken styrene molecule

21 Crosslinking – approach to polymer
Styrene free radical causes the polymer's double bond to break and allows it to accept a new pi bond

22 Crosslinking– bonding to polymer
New free radical New bond Problems: Polymers not lined up, steric interference Solution: Styrene

23 Crosslinking– approach of styrene

24 Crosslinking– activation of styrene
Styrene's double bond opens, allowing two new free radical sites

25 Crosslinking – bonding of styrene
New bond Double bond opens but can't create a bond with any other open bond because of steric effects Problems: Polymers still not lined up, steric interference Solution: Still more styrene

26 Crosslinking – bonding of 2nd styrene
Free radical New bond

27 Crosslinking– bonding with 2nd polymer
Up to 8 styrenes might be needed in the bridge New bond

28 Crosslinking– bonding with 2nd polymer

29 Crosslinking– more styrene

30 Crosslinking– more styrene

31 Crosslinking–bonding to 3rd polymer

32 Laminating Resins

33 Additives to Thermoset Polyesters
Fillers like Calcium Carbonate Tougheners like rubbers Antioxidants and UV stabilizers Reinforcements

34 Molding Compounds

35 Molding Compounds

36 Crosslinking Reactive Groups—Epoxies Plus Epoxy Rings Hardener
(amine shown)

37 Thermoset Types Epoxies

38 Vinyl Esters (VE)

39 Polyimides React with addition reaction Carbon-carbon
Double bond Imide Condensation Imide React with addition reaction

40 Thermoset Types Imides

41 Crosslinking Reactive Groups—Polyurethanes Plus Diisocyanates Polyols

42 Thermoset Types Polyurethanes

43 Crosslinking Between two Existing Polymer Chains
Polymerization Active Sites Crosslinking Active Site

44 Thank You

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