enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Conjugated system - Wikipedia

    en.wikipedia.org/wiki/Conjugated_system

    Cinnamaldehyde is a naturally-occurring compound that has a conjugated system penta-1,3-diene is a molecule with a conjugated system Diazomethane conjugated pi-system. In theoretical chemistry, a conjugated system is a system of connected p-orbitals with delocalized electrons in a molecule, which in general lowers the overall energy of the molecule and increases stability.

  3. Resonance (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Resonance_(chemistry)

    Contributing structures of the carbonate ion. In chemistry, resonance, also called mesomerism, is a way of describing bonding in certain molecules or polyatomic ions by the combination of several contributing structures (or forms, [1] also variously known as resonance structures or canonical structures) into a resonance hybrid (or hybrid structure) in valence bond theory.

  4. Pitch-based carbon fiber - Wikipedia

    en.wikipedia.org/wiki/Pitch-based_carbon_fiber

    However, the most important in carbon fiber production is mesophase pitch due to the ability to melt spin anisotropic mesophase pitch without filament breakage. The mesophase pitch forms a thermotropic crystal, which allows the pitch to become organized and form linear chains without the use of tension. Mesophase pitch is made by polymerizing ...

  5. Mesomeric effect - Wikipedia

    en.wikipedia.org/wiki/Mesomeric_effect

    In chemistry, the mesomeric effect (or resonance effect) is a property of substituents or functional groups in a chemical compound. It is defined as the polarity produced in the molecule by the interaction of two pi bonds or between a pi bond and lone pair of electrons present on an adjacent atom. [ 1 ]

  6. Carbon fiber testing - Wikipedia

    en.wikipedia.org/wiki/Carbon_fiber_testing

    A form of fatigue testing for carbon fiber components is very high cycle fatigue (VHCF). Common VHCF test methods are ultrasonic or resonance testing of tension, compression, or torsion. [ 2 ] Typically, destructive tests are carried out to validate the mechanical properties, whereas NDT is used to monitor and control the manufacturing process ...

  7. Carbon fibers - Wikipedia

    en.wikipedia.org/wiki/Carbon_fibers

    Carbon fibers or carbon fibres (alternatively CF, graphite fiber or graphite fibre) are fibers about 5 to 10 micrometers (0.00020–0.00039 in) in diameter and composed mostly of carbon atoms. [1] Carbon fibers have several advantages: high stiffness, high tensile strength, high strength to weight ratio, high chemical resistance, high ...

  8. α,β-Unsaturated carbonyl compound - Wikipedia

    en.wikipedia.org/wiki/Α,β-Unsaturated_carbonyl...

    α,β-Unsaturated carbonyls are electrophilic at both the carbonyl carbon as well as the β-carbon. Depending on conditions, either site is attacked by nucleophiles. Additions to the alkene are called conjugate additions. One type of conjugate addition is the Michael addition, which is used commercially in the conversion of mesityl oxide into ...

  9. Quinone - Wikipedia

    en.wikipedia.org/wiki/Quinone

    An example of 1,4-addition reaction is the addition of hydrogen chloride to form chlorohydroquinone: 1,4-addition reaction of quinone with hydrogen chloride to produce chlorohydroquinone. Quinones can undergo Diels–Alder reactions. [10] The quinone acts as the dienophile and reacts with a diene at a carbon-carbon double bond.