ECP 428 POLYMER SCIENCE AND TECHNOLOGY
ASSIGNMENT II
a) Nylon 11 has the following structure
Calculate its polydispersity, if the number-average degree of polymerization, Xn for
nylon is 100 and Mw = 120,000.
[6]
b) Find the ratio of butadiene to styrene repeat units in a given sample of styrene
butadiene rubber with number average molecular weight of 350000g/mol and degree of
polymerization of 4425.
[6]
c) Outline any 4 factors that affect glass transition in polymers.
[2]
d) A sample of pure high-density poly-ethylene is chlorinated such that chlorine (Cl) atoms
replace 5% of the original hydrogen (H) atoms. Assuming all the chlorine atoms added are
utilized in replacing the existing hydrogen (H) atoms and no presence of other atom
species which could potentially replace hydrogen atoms:
i.
Find the percentage weight of chlorine added.
ii.
Illustrate how the chlorinated polyethylene is different from poly (vinyl
chloride)? [2]
[4]