Question

Please choose the correct answer to this materials science question and explain why you chose that answer. I will give a positive rating if the answer is correct.

Chapter 15, Problem 15.31 Using the table shown below, which of the following polymer(s) would be suitable for the fabrication of cups to contain hot coffee: (a) polyethylene, (b) polypropylene, (c) poly (vinyl chloride), (d) polystyrene, (e) polycarbonate, and (f) PET polyester? Table 11.3 Melting and Glass Transition Temperatures for Some of the More Common Polymeric Materials Glass Transition Temperature Melting Temperature T°C (F) 115 (240) 327 (620) 137 (279) 175 (347) 265 (510) 265 (510) 212 (415) 240 (465) 265 (510) Material oC (F) Polyethylene (low density) Polytetrafluoroethylene Polyethylene (high density) Polypropylene Nylon 6,6 Poly(ethylene terephthalate) (PET) Poly(vinyl chloride) Polystyrene Polycarbonate -110 (-165) 97 (-140) 90 (-130) -18 (0) 57 (135) 69 (155) 87 (190) 100 (212) 150 (300) 0 (b), (c), (f), and (e) 0 (a), (b), and (c) O only (e) 0 (a) and (d) 0 (d) and (e)

Answer 1

Option (5) is correct i.e (d) and (e)

The amorphous polymer begin to soften at glass transition temperature. And we know maximum temperature of hot coffee is around 100° c

Therefore from the given polymers only polystyrene and polycarbonate have temperature equal or greater than 100°C.

Thus (d) and (e) are correct.