What affects the properties of polymers?

What affects the properties of polymers?

The main factors that change their properties are temperature, chain length, side groups, branching and cross linking.

What causes polymers to have different properties?

Why do different polymers have different properties? Answer: They have different chemical compositions (different monomer units), different structures, different ways of being fabricated, etc.

Which bonds change the property of a polymer?

Polymers consist of very long molecules that contain chains of carbon. They too are held together by very strong covalent bonds. There are greater intermolecular forces between the long chains compared with smaller simple molecules. This means that polymers have a higher melting point than many other organic molecules.

What are the factors that influence polymer degradation?

In general, the effects of heat, light, air and water are the most significant factors in the degradation of plastic polymers. The major chemical changes are oxidation and chain scission, leading to a reduction in the molecular weight and degree of polymerization of the polymer.

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What are properties of a polymer?

Some of the useful properties of various engineering polymers are high strength or modulus to weight ratios (light weight but comparatively stiff and strong), toughness, resilience, resistance to corrosion, lack of conductivity (heat and electrical), color, transparency, processing, and low cost.

What is polymer and its properties?

Polymers are materials made of long, repeating chains of molecules. The materials have unique properties, depending on the type of molecules being bonded and how they are bonded. Some polymers bend and stretch, like rubber and polyester. The term polymer is often used to describe plastics, which are synthetic polymers.

What are properties of polymer?

Do polymers have different properties?

Because of the structure of the molecules, polymeric materials have different properties compared to other materials, like metals. Specifically, the relatively high molecular weight and long polymer chain length result in entanglement, and the lack of covalent intermolecular bonds facilitates polymer chain mobility.

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What are the properties of a polymer?

What are 3 properties of polymers?

Heat capacity/ Heat conductivity. The extent to which the plastic or polymer acts as an effective insulator against the flow of heat.

  • Thermal expansion. The extent to which the polymer expands or contracts when heated or cooled.
  • Crystallinity.
  • Permeability.
  • Elastic modulus.
  • Tensile strength.
  • Resilience.
  • Refractive index.
  • How does a polymer degrade?

    3.6 Polymer degradation Degradation is often due to a change in the chemical and/or physical structure of the polymer chain, which in turn leads to a decrease in the molecular weight of the polymer. The degradation of polyethylene occurs by random scission—a random breakage of the bonds within the polymer.

    How can polymers be broken down?

    Polymers are broken down into monomers via hydrolysis reactions, in which a bond is broken, or lysed, by addition of a water molecule.

    What are the main ways to change the properties of polymers?

    Overall, the main ways to change and tune the properties of a polymer include changing the length of the polymer chains, creating branched chains from linear polymer chains, crosslinking the polymer chains and adding plasticizers into the polymer.

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    What are the properties of branched polymer chains?

    On the other hand, branched chains are less stretchy, less dense and have lower tensile strengths for the opposite reasons (less movement over each other, lower molecules per area, and weaker van der Waals interactions). The other two ways to change the properties of a polymer are through cross-linking the polymer and the addition of plasticizers.

    How does cross-linking change the chemical nature of a polymer?

    Cross-linking the polymer changes the chemical nature of the polymer if a chemical is used (in some cases there are physical cross-link can occur where the polymer chains interlink and are held via intermolecular interactions rather than chemical bonds).

    Why do longer polymer chains have a higher melting point?

    When the polymer chains are longer, they become more tangled, which means that they stick together better. So, it becomes harder to break the bonds between the chains, which increases the melting point. The reverse scenario is applicable when lower melting points are required (less entanglement, easier to break).