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30 Cards in this Set
- Front
- Back
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Polymers |
Are long chain giant organic molecules assembled from many smaller molecules called monomers or mers. |
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High polymer |
Molecules with a very high degree of polymerization |
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Telenomers or Oligonomers |
Polymers with degree of polymerization of less than 10 |
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Degree of polymerization DP |
MWpolymer/MWmer The average number of mer-units in a chain |
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Copolymer/interpolymer |
Large molecule with 2 alternating mers. |
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Homopolymer |
Only one kind of repeating unit along a chain |
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Elastomers |
With plastic properties similar to rubber |
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Common polymer materials |
Fiber(discrete elongated pieces) Asphalt(black/highly viscous liquid) Natural rubber(elastic hydrocarbon polymer) Elastomers Plastics Adhesives(mixture in a liquid or semiliquid state that adhers or bonds item together) |
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Ceramics |
Composed of compound that contains metallic and non-metallic elements and the atoms are held together by strong atomic forces either covalent or ionic bond. |
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Common ceramics |
Glass Brick Portland Cement Refractories Abrasives |
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Properties of Materials |
Chemical properties Physical Properties Mechanical properties Dimensional Properties |
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Chemical properties |
Composition Corrosion Resistance Crystal Structure Microstructure Stereospecificity |
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Physical Properties |
Curie Point Density Dielectric strength Electrical Resistivity Heat Distortion Temperature Melting Point Poisson's Ratio Refractive Index Specific gravity Thermal conductivity Thermal expansion |
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Mechanical Properties |
Compressive strength Creep Creep strength Endurance limit Flexural strength Hardness Modulus of Elasticity Percent elongation Percent reduction in area Shear strength Yield strength Toughness Brittleness Elasticity Plasticity Ductility Stiffness |
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Dimensional Properties |
Camber Lay Out of flat Roughness Surface finish Waveness |
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Bonding in Materials |
Ionic Bond Covalent Bond Metallic Bond |
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Ionic Bond |
The atoms of one element give up their outer electron, w/c in turn attracted to the atom of some other element. |
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Covalent Bond |
Electrons are shared between atoms in their outermost shell |
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Metallic Bond |
Involves the sharing of outer shell electrons in all electrons to form general electron cloud |
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Classification of Materials |
Metals Ceramics Composites Polymers |
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Advance Materials |
Semiconductors Nanomaterials Biomaterials Smart Materials |
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Metals |
Normally combinations of metallic elements. They have large numbers of nonlocalized electron, that is, these electrons are not bound to particular atoms. |
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Ceramics |
Are compounds between metallic and non metallic elements; they are most frequently nitrides, oxides and carbides. Hard but very brittle Insulative to the passage of electricity and heat Resistant to high temperatures and harsh environment |
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Polymers |
Include the familiar plastic and rubber materials. Very large molecular structures Low density and extremely flexible Many of them are organic compounds that are chemically based on carbon, hydrogen and other non metallic elements. |
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Composites |
Consist of more than one material type Example: fiberglass |
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Biomaterials |
Employed in components implanted into the human body for replacement of diseased or damaged body parts. |
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Advanced materials |
Utilized in high-technology applications Example: computers, aircraft, spacecraft, electronic equipment and military rocketry. |
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Smart materials |
Group of new and state-of-the-art materials. Example: sensor, actuator, |
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Nanomaterials |
Example: carbon nanotube |
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Semiconductors |
Have electrical properties that are intermediate between the electrical conductors and insulators. |
