Question

snowboards are typically made out of a thermosetting polymer (i.e. a three dimensionally connected glassy polymer). what type of mechanical behavior would you expect from that type of polymer and why do you suppose reinforcing the polymer with fiber would alleviate problems that might occur due to the mechanical behavior of the polymer?

Answer 1

Thermosetting plastics are generally stronger than thermoplastic materials due to the three-dimensional network of bonds (crosslinking), and are also better suited to high-temperatureapplications up to the decomposition temperature since they keep their shape as strong covalent bonds between polymer chains cannot be easily broken. The higher the crosslink density and aromatic content of a thermoset polymer, the higher the resistance to heat degradation and chemical attack. Mechanical strength and hardness also improve with crosslink density, although at the expense of brittleness.

Thus thermoset plastic are brittle and to increase their fluxural strength and stiffness they are reinforced with fiber that induces strength in compression and tension.