1. When acetone dissolves the polymer, the gas present in the foaming agent is allowed to evaporate and is removed from the structure. The polymer becomes more compact and denser as the polymer collapses on itself due to the absence of the gas.

2a. Low density polyethylene(LDPE) is made from ethylene and has an increased amount in branched bonds when compared to HDPE. The Branched arrangement of LDPE results in weak intermolecular bonds within LDPE and results in lower tensile strength, that is, the resistance against forces that pulls apart a material. Hence it does not provide the required density and strength for surgical gloves that will allow the Spectra liner to be highly resistant to being cut or torn.

2b. Linear arrangement of HDPE provides the required density and strength so that the Spectra liner will be highly resistant to being cut. However, to give its required flexibility, the use of a thinner layer of the HDPE will provide the characteristic.

3.When the piece of plastic is stretched, the strip narrows and “necks down”. The molecules become aligned and parallel to each other and follows the direction of the pulling force. The change in the structure is irreversible, and if the pulling persists, the plastic breaks. As the same pulling force is applied to a piece of paper, the paper tears rather than stretching. The cellulose molecules in paper are held more rigidly in place, and it is not possible to become aligned and be parallel to each other.

4a. The four properties of polymers are, non-toxic, stable over time of intended use, lack of reactivity in body fluids, and ease of implementation.

b. Rigid gas permeable lenses are made up of Polymethyl methacrylate (PMMA) while soft contact lenses are made up of Polymacon and polymer of 2-hydroxyethyl methacrylate (HEMA). The desirable properties of these materials are, non-toxic, permeable to oxygen, comfortable to wear, inexpensive. It can also be easily washed and due to its flexible property, it allows contact lenses to fit into the shape of a person’s eye easily.

c. Hard contact lenses are made up of PMMA while soft contact lenses are made up of silicone. The difference of material used allows soft contact lenses to be more comfortable to wear since it has a better fit to the eye and allows oxygen to reach the eye.