Properties of materials

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Question 9
Medium

The table below shows information about four different polymers:

PolymerCost (£ per kg)Tensile strength (MPa)Melting point (∘C)Maximum usable temp. (∘C)A2.1035140110B3.4055180150C4.8575210160D2.8048175145 \begin{array}{|c|c|c|c|c|} \hline \text{Polymer} & \text{Cost (}\text{£}\text{ per kg)} & \text{Tensile strength (MPa)} & \text{Melting point } (^\circ\text{C}) & \text{Maximum usable temp. } (^\circ\text{C}) \\ \hline \text{A} & 2.10 & 35 & 140 & 110 \\ \hline \text{B} & 3.40 & 55 & 180 & 150 \\ \hline \text{C} & 4.85 & 75 & 210 & 160 \\ \hline \text{D} & 2.80 & 48 & 175 & 145 \\ \hline \end{array} PolymerABCD​Cost (£ per kg)2.103.404.852.80​Tensile strength (MPa)35557548​Melting point (∘C)140180210175​Maximum usable temp. (∘C)110150160145​​

A medical manufacturer wants to select one of these polymers to make a reusable surgical instrument tray.

The tray has the following design requirements:

  • It must withstand repeated steam-sterilisation in an autoclave at 135∘C135^\circ\text{C}135∘C without deforming or degrading.
  • It must have a tensile strength of at least 50 MPa to avoid bending under the weight of surgical tools.
  • The manufacturing cost must be kept as low as possible.

Identify which polymer is the most suitable for making this tray. Justify your answer by evaluating the properties of all four polymers.

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Properties of materials Questions

  1. GCSE
  2. /Chemistry
  3. /Properties of materials