Question

Question 3

(a) I am engineering material science student (AIT). A senior family member back at my village has had an accident over the weekend with a broken hip and the Doctors have suggested that he should have material implant (Materials for Hip Prosthesis). What type of material would you choose for an implant for a total hip replacement and why? (Please consider the following factors for your decisions: biocompatibility, corrosion resistance, high fracture toughness, excellent fatigue life (so that implants last for many years since it is difficult to do the surgery as patients get older), and wear resistance)

(b) COV-19 has brought difficulties and changes in life style for everybody in and outside Ghana. Mr. Haruna needs water storage tank, and he wants it to be made from metal, but he wish to coat the metal with a 3-mm thick polymer as an intermediate layer between the metal and additional insulation layers. The temperature of the intermediate layer may drop to -80°C.

What type of polymer material will you choose for this coat (layer) and why?

(C) COV-19 has come to stay with us, and we need personal protective equipment (PPEs) to go about our daily work (activities). As Engineering material science student ,what type of polymer material will you recommend for the following applications and why?:

(i) A surgeon’s glove,

(ii) A beverage container,

(iii) And a pulley.

Answer 1

A)There are essentially 5 types of material implants used for hip prosthesis. They are:

1.Metal-on-metal

2.Metal-on-polyethylene

3.Ceramic-on-metal

4.Ceramic-on-polyethylene

5.Ceramic-on-ceramic.

Out of above 5, Metal-on-polyethylene is proven to be more effective and efficient on age group of 65 years and above. These are some advantages of the mentioned implant.

1.Good bearing surface especially for old age people was once taken as gold standard by THA.

2.Non reactive, unlike metals.

3.Cost efficient.

B) considering the layer of the polymer is an intermediate one, its main purpose is to keep the inside temperature constant to certain extent.

There are 3 viable options for this purpose:

1. Polypropylene

2. Polyethylene

3. Fibres

Out of these 3, polyethylene would be most viable as the rest of the two won't be able to sustain negative temperatures of - 80 degrees and polyethylene is known to keep the water free of unwanted contacts especially in time of cov 19 situation.

C)

i) In general use, latex, or any other polymer based gloves would have done the trick but in case of COVID 19 situation, gloves which are easily disposable and provide zero contact with the affected person is the need. Hence neoprene gloves are the best to use.

Neoprene gloves are made up of a combination of chlorine, carbon, and hydrogen, crosslinked as polymers using sulfur. These gloves are not as commonly used, but they combine the properties of latex and nitrile. They provide a good fit and are durable and free of allergens while providing protection from chemicals and bodily fluids.

ii) various types of beverage containers are plastic, aluminium, glass and paperboard which are used commercially. Although they can be lethal in covid situation, as the virus can easily be transmitted through all of these material types.

Hence an aseptic container is ideal in such case which also claims to be the future of beverage containers with claiming 75 percent usage till 2028 and also can be used after multiple washes.

iii) a pulley in daily life can be seen attached to the wells to pull up water using a rope. Although in covid situation, this pulley can be proved lethal if a covid positive person comes in contact with it and virtually affecting everyone who comes in contact with it.

In such situation using our own pulley is advisable and especially a plastic polymer one especially made of a thermosetting polymer which can be used for multiple purposes and also safer than metal pulleys to certain extent considering the COV 19 situation.