1. THERMOSETS 05.03.2010

2. Thermosets Cross-linked in a 3d network. Strength of bond. Hardness & strength in material not affected by temperature. Polymerization will require heat & pressure so that the shape of the part is permanently set.(curing) Irreversible. Decomposes. Chars.

3. Thermosets Tg not sharply defined. Become rubbery over a narrow range. Polymerization in 2 steps. At chemical plant & at parts-producing plant. Phenolics. Pots & pans. Possess better insulating, mechanical & chemical properties. Also better dimensional stability.

4. Mechanical Properties

6. Melamine/Aminos Formica is a brand of composite materials which are heat-resistant, wipe-clean, plastic laminate with melamine resin. If exposed to enough heat, melamine will decompose. For this reason, melamine dishware should not be exposed to high temperatures like those in the oven and microwave.

7. Advantages of Melamine Toxicity, None- Extinguishing, Self- Halogen Content, None- Electrically Insulating- Hardness, High- Gloss, High- Scratch Resistant- Copolymer- Strength, High

8. Melamine Uses for melamine include floor tiles, kitchenware, fire retardant fabrics, and commercial filters. Melamine is an organic compound that is often combined with formaldehyde to produce melamine, a synthetic polymer which is fire resistant and heat tolerant. melamine releases water.

10. Copolymer A heteropolymer or copolymer is a polymer derived from two (or more) monomeric species, as opposed to a homopolymer where only one monomer is used

11. Epoxies Excellent mechanical & electrical properties. Good dimensional stability & excellent adhesive properties. Application requiring mechanical strength & thermal insulation. Used as coatings & adhesives.

12. Epoxies have low shrinkage, good chemical resistance, excellent adhesive properties. Downsides are the higher cost, a need for an accurate resin/hardener ratio (epoxies use a hardener not a catalyst, and the ratio will vary) when mixing and the need for skin protection.

14. Disadvantages Strongly exothermic, this can lead to cracking. Contracts on curing (up to 8%). Protective measures must be taken before mixing and using any of the thermosetting resins. High temperature & pressure required UV-sensitive

16. Designing With Thermosets there are potential pitfalls which can lead to designs difficult to produce, or costly failures in the field. The first important consideration is stiffness. far more rigid and dimensionally stable than thermoplastic.

17. Designing With Thermosets For applications requiring precise dimensional tolerances and low deformation under load, thermosets are an excellent choice. another important design criterion is associated with cross section thickness. Impact strength is another area requiring special attention. Applications which require flat surfaces may best be molded from a thermoset.

18. Thermosets As A Replacement For Metal Because of their dimensional stability, high strength, and thermal resistance, thermosets are often chosen as an alternative to metals. Potential benefits include cost saving, weight reduction, and improved chemical and corrosion resistance.