An unknown polymer sample was found to have the following molecular weight distribution:Molecular weight range8,000 - 20,00020,000 - 32,00032,000 - 44,00044,000 - 56,00056,000 - 68,00068,000 -80,00080,000 - 92,0000.03Knowing that the monomer is methyl methacrylate, which of the below is the number average degree of polymerization for this polymer sample?Select one:O a.O b. DP 476O C.DP = 338DP = 664O d. DP 544O e. DP = 801Xi0.050.150.210.280.180.10Wi0.020.080.170.290.230.160.05

The DOP tells us the number of monomer units in the given polymerization reaction.

An unknown polymer sample was found to have the following molecular weight distribution: Molecular weight range 8,000 - 20,000 20,000 -32,000 32,000 - 44,000 44,000 - 56,000 0.23 56,000-68,000 0.16 68,000-80,000 80,000 - 92,000 0.03 0.05 Knowing that the monomer is methyl methacrylate, which of the below is the number average degree of polymerization for this polymer sample? Xi 0.05 0.15 0.21 0.28 0.18 0.10 Wi 0.02 0.08 0.17 0.29

An unknown polymer sample was found to have the following molecular weight distribution: Molecular weight range 8,000 - 20,000 20,000 -32,000 32,000 - 44,000 44,000 - 56,000 0.23 56,000-68,000 0.16 68,000-80,000 80,000 - 92,000 0.03 0.05 Knowing that the monomer is methyl methacrylate, which of the below is the number average degree of polymerization for this polymer sample? Xi 0.05 0.15 0.21 0.28 0.18 0.10 Wi 0.02 0.08 0.17 0.29

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

See similar textbooks

Similar questions

An unknown polymer sample was found to have the following molecular weight distribution: Molecular weight range 8,000 - 20,000 20,000 - 32,000 32,000 - 44,000 44,000 - 56,000 56,000 -68,000 68,000 -80,000 80,000 - 92,000 Having a DP=763, which of the following common polymers is this sample? Xi 0.05 0.15 0.21 0.28 0.18 0.10 0.03 Wi 0.02 0.08 0.17 0.29 0.23 0.16 0.05 Select one: O a. Polymethylmethacrylate with a monomer molecular weight of 100.121 g/mol O b. Polystyrene with a monomer molecular weight of 104.15 g/mol Polycarbonate with a monomer molecular weight of 61.0168 g/mol O c. O d. Polyvinyl chloride with a monomer molecular weight of 62.498 g/mol Polypropylene with a monomer molecular weight of 42.08 g/mol O e.
Molecular weight data for some polymer are tabulated here. Compute (a) the number-average molecular weight, (b) the weight-average molecular weight. (c) If it is known that this material's degree of polymerization is 710, which one of the polymers listed in Table 14.3 is this polymer? Why? Molecular Weight Range g/mol 15,000-30,000 Xi Wi 0.04 0.01 30,000-45,000 0.07 0.04 45,000-60,000 0.16 0.11 60,000-75,000 0.26 0.24 75,000-90,000 0.24 0.27 90,000 105,000 0.12 0.16 105,000-120,000 0.08 0.12 120,000-135,000 0.03 0.05
For a given polymer, the activation energy for the stress relaxation was measured to be 59kj/mol. If the stress relaxation time for this polymer at 7 degree Celsius is 3150 seconds. What is the relaxation time at 110 degree Celsius
( B ) A stress of 6.7 MPa is employed to one type of a polymer under constant strain . After 40 days at 20 ° C the stress is reduced to only 8.4 MPa . When the same polymer is heated to 40 ° C the relaxation time is 40 days . 1- Calculate the relaxation time constant for this material at 25 ° C ? 2- Estimate the stress after 50 days at 25 ° C ? 3- Estimate the stress relaxation activation energy for the same polymer .
Please make sure to display your thought process? It is imperative to be able to follow how the answer was deduced. Please be as thorough as possible. Please address all parts of this question as they are all part and critical to answering this question correctly. Please show good integrity when answering the question: Strain-rate, temperature, pressure, and aging time all affect the stress/strain behavior of polymers. Draw a stress-strain curve below for a typical ductile polymer. Clearly label the yield point and the ultimate tensile strength. Using this curve draw two new curves corresponding to same polymer but now tested at: 1) an increase in temperature and 2) an increase in strain rate. Explain what happens to the tensile behavior after: a) a prolong time of aging time is increased and b) when the tensile tests are conducted under super imposed hydrostatic compression
Q5 (a) Figure 6 shows two types of polymeric products fabricated using different processing techniques. Suggest with justification for the type of processes used to produce the products: i. Product A ii. Product B A B Figure 6. Two types of polymeric products (a) plastic bottles and (b) plastic car boot tray (b) The molecular weight data of a Polymer X are given in Table 3. Once undergone a melting process, it achieves degree of polymerization, DP of 498 upon solidification. i. Calculate the number-average molecular weight (Mn) for the polymer. ii. Calculate the molecular weight for monomers of the Polymer X. iii. Prove that the Polymer X is a polytetrafluoroethylene (PTFE) with chemical formula of (C2F4)n- Given the atomic weights for carbon, C is 12.011 g/mol and fluorine, F is 18.998 g/mol.
Which of the statements below are accurate regarding the stress-strain behavior of polymers: (This question has more than one correct answer) а. Strain softening happens in elastomers where the deformation gradually leads to a decrease in stress under constant strain rate b. As temperature is reduced, the necking behavior of plastic tensile bars completely disappears C- The slope of the stress-strain curve for totally elastic and brittle polymers is always positive d. The stress-strain curve for vulcanized elastomers has a greater slope than unvulcanized polymers throughout
An unknown polymer sample was found to have the following molecular weight distribution: Molecular weight range Xi Wi 8,000 – 20,000 0.05 0.02 20,000 – 32,000 0.15 0.08 32,000 – 44,000 0.21 0.17 44,000 – 56,000 0.28 0.29 56,000 – 68,000 0.18 0.23 68,000 – 80,000 0.10 0.16 80,000 - 92,000 0.03 0.05 What would the weight average molecular weight of the sample be if, we had filtered the monomer mixture with a 44 kDa dialysis tubing before preparation? (Hint: a dialysis tubing of a known molecular weight, only keeps molecules larger than that size)
Polymer Engineering question: Explain doping process and why this process important for conductive polymer?
Question Seven (Plastics) The data below is from a fibre reinforced plastic. Would this composite be suitable for use at 400°C? Explain your answer. Temperature (°C) 20 100 200 300 400 500 600 Plastic A Plastic B Plastic C Yield Strength (MPa) 270 350 47 Tensile Strength (MPa) 300 500 52 E (GPa) 130 3 14 115 100 95 Question Eight (Plastics) Identify the thermoplastic, the elastomer and the thermoset. 70 58 0 Young's Modulus (GPa) Elongation (%) 12 3 600
Connecting rod (as shown below) is a car part that connects engine piston to crankshaft and converts reciprocating motion into rotating motion. It performs under load at high temperature around 150°C. Long carbon fiber thermoplastic composite (LFT) with 30% carbon fiber has been considered to replace metal (steel or aluminum) rod to improve efficiency. Based on the data for different polymers listed in the table above, which polymer(s) would you choose as the polymer matrix for the connecting rod? What is your rationale?
Polymer deterioration by swelling may be reduced by which of the following? Increasing degree of crosslinking, increasing molecular weight, and decreasing degree of crystallinity Decreasing degree of crosslinking, decreasing molecular weight, and decreasing degree of crystallinity Increasing degree of crosslinking, increasing molecular weight, and increasing degree of crystallinity Decreasing degree of crosslinking, increasing molecular weight, and increasing degree of crystallinity