POLYMER ENGINEERING - QUESTION 24.3 : The molecular weights M in kg / mol of 3 different monomers a, b and c in a polymer are Ma = 14, Mb = 16 and Mc = 18, with their respective quantities in N units having the ratio of Na : Nb : Nc = 2 : 3 : 5. (a) Find the numerical average molecular weight of the polymer by using the formula (Ma Na + Mb Nb + Mc Nc) / (Na + Nb + Nc). (b) Find the weighted average molecular weight of the polymer by using the formula (Ma Na Ma + Mb Nb Mb + Mc Nc Mc) / (Ma Na + Mb Nb + Mc Nc). (c) Calculate the polydispersity Q by using the answer in (b) divided by answer in (a). (d) Find the volumetric average molecular weight of the polymer by using the formula (Ma Na Ma Ma + Mb Nb Mb Mb + Mc Nc Mc Mc) / (Ma Na Ma + Mb Nb Mb + Mc Nc Mc). (e) Estimate the polydispersity Q by using the answer in (d) divided by answer in (b).
- 1 Answers
- 1513 Views
- I also Faced
- E-Mail Answers
Answer Posted / kangchuentat
POLYMER ENGINEERING - ANSWER 24.3 : (a) Numerical average molecular weight = (Ma Na + Mb Nb + Mc Nc) / (Na + Nb + Nc) = (14 x 2 + 16 x 3 + 18 x 5) / (2 + 3 + 5) = 166 / 10 = 16.6 kg / mol. (b) Weighted average molecular weight = (Ma Na Ma + Mb Nb Mb + Mc Nc Mc) / (Ma Na + Mb Nb + Mc Nc) = (14 x 2 x 14 + 16 x 3 x 16 + 18 x 5 x 18) / (14 x 2 + 16 x 3 + 18 x 5) = 2780 / 166 = 16.747 kg / mol. (c) Polydispersity = [ answer in (b) ] / [ answer in (a) ] = (16.747 kg / mol) / (16.6 kg / mol) = 1.0089. (d) Volumetric average molecular weight = (Ma Na Ma Ma + Mb Nb Mb Mb + Mc Nc Mc Mc) / (Ma Na Ma + Mb Nb Mb + Mc Nc Mc) = (14 x 2 x 14 x 14 + 16 x 3 x 16 x 16 + 18 x 5 x 18 x 18) / (14 x 2 x 14 + 16 x 3 x 16 + 18 x 5 x 18) = 46936 / 2780 = 16.883 kg / mol. (e) Polydispersity estimation = [ answer in (d) ] / [ answer in (b) ] = (16.883 kg / mol) / (16.747 kg / mol) = 1.0081. The answer is given by Kang Chuen Tat; PO Box 6263, Dandenong, Victoria VIC 3175, Australia; SMS +61405421706; chuentat@hotmail.com; http://kangchuentat.wordpress.com.
| Is This Answer Correct ? | 0 Yes | 0 No |
Post New Answer View All Answers
In Pressure Sfety Valve(PSV) 2" by pass line why given for process units.
Please help to get IOCL/HPCL or other chemical engineering paper pls send kathir_skv@yahoo.com Regards, kathirvel
Explain how can you keep our seawater used for heat rejection clean before entering our heat exchangers?
Explain the procedure to estimate the friction factor involved in heat exchanger tubes?
What are the advantages of using a ball mill over other conventional methods of crushing?
Explain how can I evaluate the thermal relief requirements for double block-in of 98% sulfuric acid?
Explain how can you determine the proper pipe thickness for a slurry line?
What compounds are responsible for the odors that come from wastewater treatment plants?
At what temperature is glass fused to steel in the making of glass-lined equipment?
print a pattern of abcdcba abc cba ab ba a a ab ba abc cba abcdcba
What is the best way to handle bend or turns in slurry piping systems?
What step should be taken in process industries if the process variable is oscillating?
Why in a continuous plant for a Hot standby screw pump system the interlock for auto starting of the other pump ( when the running pump stopped suddenly) is given with header pressure only? why not with flow rate or current of the pump?
How can you keep our seawater used for heat rejection clean before entering our heat exchangers?
What is the angle of repose and what are its applications in the chemical industry?
