ENGR 2300 Chapter 14

Which type(s) of bonds are found between atoms within hydrocarbon molecules? A. Ionic bonds B. Hydrogen bonds C. Covalent bonds D. van der Waals bonds E. Metallic bonds

Which of the following form network polymers? A. Rubber, polyethylene, and phenol-formaldehyde B. Epoxy and phenol-formaldehyde C. Polystyrene and nylon D. Polyethylene, polystyrene, and nylon

Name the term used for the configuration of a stereoisomer having R groups whose positions alternate from one side to the other side along the backbone chain.

How do the densities of crystalline and amorphous polymers of the same material and having identical molecular weights compare? A. Density of crystalline polymer < Density of amorphous polymer B. Density of crystalline polymer = Density of amorphous polymer C. Density of crystalline polymer > Density of amorphous polymer

For the following two polymers do the following: indicate if it is not possible to determine if one polymer is more likely to crystallize than the other. On the other hand, if it is possible to make such a determination then indicate which of the two is more likely to crystallize. Linear polyethylene Lightly branched isotactic polypropylene A. Lightly branched isotactic polypropylene B. Linear polyethylene C. Not possible

Calculate the percent crystallinity (%) of a polymeric material having a density of 0.935 g/cm3 given the following information: (a) There are the equivalent of 12 mer units associated with each unit cell. (b) The unit cell is orthorhombic (i.e., α = β = γ = 90°), with edge lengths of 0.656, 2.172, and 0.713 nm. (c) The mer molecular weight is 103 g/mol. (d) The density of the totally amorphous material is 0.806 g/cm3.