High-performance lower-limb prosthetic sockets must be both durable and comfortable for the user. They are often manufactured with a soft, lightweight poly(ethene) inner liner surrounded by a highly rigid, carbon-fibre reinforced polyester composite outer shell.
The displayed structural formula of poly(ethene) is shown below:
[HH∣∣−C−C−∣∣HH]n\left[ \begin{array}{cc} \text{H} & \text{H} \\ | & | \\ -\text{C} & -\text{C}- \\ | & | \\ \text{H} & \text{H} \end{array} \right]_nH∣−C∣HH∣−C−∣Hn
An incomplete displayed structural formula of the monomer ethene is shown below:
HH CC HH\begin{array}{cc} \text{H} & \text{H} \\ \ \ \text{C} & \text{C} \\ \ \ \text{H} & \text{H} \end{array}H C HHCH
Complete the structural formula of the monomer ethene by describing the necessary bonds to connect all the atoms correctly.
The rigid outer shell of the prosthetic contains a polyester. Two monomers, X and Y, are reacted to make this polyester:
Name the functional group in monomer Y.
Monomers X and Y undergo condensation polymerisation to produce the polyester and a small molecule. Name this small molecule.
Explain, in terms of structure and bonding, why this polyester outer shell melts when it is heated.
The outer shell is a composite material containing carbon fibres embedded in a polyester resin matrix. Match each material to its correct role as either the matrix or the reinforcement:
Suggest two physical or mechanical reasons why this tough, rigid composite outer shell is added to the soft poly(ethene) inner liner.