Structure and Properties of Polymers

Structure and Properties of Polymers

1. If polymer chains are packed close together the material will have a high density vice versa

2. Chains which are held together by weak forces can slide over each other, this makes stretchy plastic with a low melting point

3. Chains held together by strong bonds have higher melting points and cant be easily stretched as the crosslinks hold the chains firmly together. Crosslinks are chemical bonds between the chains

4. Polymers can be modified to give them different properties

   • You can increase chain length
   • Adding cross linking agents to make them stronger
   • Plasticisers can be added to a polymer to make it softer [by reducing forces between molecules]
   • Making them crystalline = stronger, higher density, high melting point