Question

1. This question is related to your knowledge of how chemical structure affects a polymer’s glass transition temperature. For each pair below draw the repeat unit of the polymers, select which polymer you believe has a higher glass transition temperature, and explain

Pair 1: polyethylene versus poly(vinyl alcohol)

Pair 2: poly(hydroxyethyl methacrylate) versus poly(propyl methacrylate)

Pair 3: polyethylene versus polypropylene

2. You have polymerized a product containing seven PMMA molecules: three of the molecules have a degree of polymerization of 150; two of the molecules have a degree of polymerization of 400; one has a degree of polymerization of 500; and the last has a degree of polymerization of 1000. Calculate the num­ber average and weight average molecular weights of the polymer product and the polydispersity index. Ignore the presence of initiator fragments.

3. Your PI asks you to design a polymer biomaterial for use as a tooth enamel replacement. Based on the characteristics we have talked before, what biomaterial properties are needed and how would you go about designing such a material? (Hint: think from different aspects: stability, how is interact with water, mechanical property)

4. Which one or more of the following polymers would be suitable for the fabrication of cups to contain hot coffee: Polyethylene, polypropylene, poly(vinyl chloride), polyester (PET), polycarbonate? Why?

Which of these will be suitable for ice cube trays? Why

Answer 1