POLYMER ENGINEERING - QUESTION 24.1 : 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. The fraction of polymer chain X of 3 different monomers a, b and c in a polymer are Xa = 0.5, Xb = 0.3 and Xc = 0.2. (i) Calculate number average molecular weight by using the formula Ma Xa + Mb Xb + Mc Xc. (ii) Calculate weight average molecular weight by using the formula (Ma Xa Ma + Mb Xb Mb + Mc Xc Mc) / (Ma Xa + Mb Xb + Mc Xc). (iii) Calculate the polydispersity by using the answer in (ii) divided by answer in (i). (iv) If the molecular weight of repeat unit is 12, calculate the degree of polymerization by using the formula (Ma Xa + Mb Xb + Mc Xc) / (molecular weight of repeat unit).
Answer Posted / kangchuentat
POLYMER ENGINEERING - ANSWER 24.1 : (i) Number average molecular weight = Ma Xa + Mb Xb + Mc Xc = 14 x 0.5 + 16 x 0.3 + 18 x 0.2 = 15.4 kg / mol. (ii) Weight average molecular weight = (Ma Xa Ma + Mb Xb Mb + Mc Xc Mc) / (Ma Xa + Mb Xb + Mc Xc) = (14 x 0.5 x 14 + 16 x 0.3 x 16 + 18 x 0.2 x 18) / 15.4 = 15.558 kg / mol. (iii) Polydispersity = [ answer in (ii) ] / [ answer in (i) ] = 15.558 / 15.4 = 1.0103. (iv) Degree of polymerization = (Ma Xa + Mb Xb + Mc Xc) / (molecular weight of repeat unit) = (15.4 kg / mol) / (12 g / mol) = 1.283 k = 1283. 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
How can you control the ph level in our cooling water with respect to ammonia contamination?
What is the purpose of capacitor?
How can hexavalent chromium be removed from aqueous waste streams?
PLZ ANYONE SEND ME PLACEMENT PAPERS OF I.O.C.L MY ID---- gaurav.nitw.5609@gmailcom
What type of pump may be appropriate for a liquid near saturation, a low flow rate, and very limited npsha (net positive suction head available)?
I am a Diploma Chemical Engineer by Nirma Uni; and BEng (Hons) Energy & Environmental Engineer by Napier Uni; Edinburg, UK. HPCL chemical engineering test will held on 14th July,09. So, Please send me some previous chemical engineering papers Objective types Or material to give the test.
Is there any way to repair a valve that is passing leaking internally without taking our process offline?
What is screen analysis?
which materials can l use if l want to use length wave 680 to 900 in hplc
hi i need cpcl written exam question papers if anybody pls help me
Can asphalt be recycled to form a useful product?
How fouling effected the heat transfer rate?
Hi, I am Gurunathan. I am in need of ONGC, IOCL, DRDO technical test ( chemical engineering)and general aptitude questions. If anyone has kindly post it to me soon.
What are the methods involved to test helium leak testing in a vacuum system?
What is pneumatic conveying?