Question

Based on the following molecular weight data of polypropylene, determine the degree of polymerization Molecular Weight Range (g/mole) Number Fraction (xi) Weight Fraction (wi) 8,000 - 16,000 0.05 0.03 16,000 - 24,000 0.17 0.08 24,000 - 32,000 0.22 0.18 32,000 - 40,000 0.25 0.35 40,000 - 48,000 0.22 0.27 48,000 - 56,000 0.09 0.09

Answer 1

Answer:

785

Explanation:

Molecular. X. W

Weight

8000-16000 0.05 0.03

16000-24000. 0.017. 0.08

24000-32000. 0.22. 0.18

32000-40000. 0.25. 0.35

40000-48000. 0.22. 0.27

48000-56000. 0.09. 0.09

Mean weight X*M. W*M

12000. 600. 240

20000. 3200. 2000

28000. 6720. 5600

36000. 10080. 10800

44000. 8800. 11880

52000. 3640 3640

Total=33040g\mol 36240

Note before repeat molecular weight m= 3*12.01+6*1.008=

42.08g/mol

Degree of polymerization= total W*M/w=33040/42.08 =785