Now it is possible to compute the degree of polymerization using Equation 14.6 as 14.4 (a) Compute the repeat unit molecular weight of polystyrene. When considering the molecular weight of a polymer for the above calculation, we usually take either the number average molecular weight (M n) or weight average molecular weight (M w). Formula to Calculate Number Average Molecular Weight. For a given molecular weight the relaxation spectra at ... energy represented by this distribution was associated with an activation energy required for the motion of a chemical repeat unit. It is well known that the glass transition temperatures, Tgs, of supported polystyrene (PS) films decrease dramatically with decreasing film thickness below 60-80 nm. (b) Compute the number-average molecular weight for a polystyrene for which the degree of polymerization is 25,000. 7.7 for the mer structure of polycarbonate.) This can be accounted for by the molecular weight dependence of the density of repeat units of a polymer coil in solution. A . (b) Compute the number-average molecular weight for a polypropylene for which the degree of polymerization is 15,000. Expert Answer 100% … Compute the repeat unit molecular weight of polystyrene. Molecular weight is an important parameter for synthetic polymers ... mass of repeat units and end-group mass structure. Students also viewed these Thermodynamics questions (b) Compute the number-average molecular weight for a polystyrene for which the degree of polymerization is 26,000. The molecular weight is the sum of the weights of all the repeat units plus the weight of the end groups. Repeating units Polymer molecules are very large compared with most other molecules , so the idea of a repeat unit is used when drawing a displayed formula. m = 3(AC) + 6(AH) = (3)(12.01 g/mol) + (6)(1.008 g/mol) = 42.08 g/mol. Get the detailed answer: Compute the repeat unit molecular weight of polypropylene, Compute the number-average molecular weight for a polypropylene for whi For MW = 1,000 units x 104.15 Da/unit + 2 Da = 104,152 Da. monomeric unit. Its molecular weight can be as high as 5 × 10 6. T able 8.7 Molecular Weights of PET Samples . Polystyrene MW is shown to have no significant impact on the film thickness dependence of Tg − Tg,bulk. You need to know the number of repeat units in the chain and multiply the monomer molecular weight by that number. 3 the number-average molecular weight of a polystyrene is 500,000 g/mol. For a polystyrene solution with a bimodal molecular weight distribution, the coefficient A is smaller than for either of the monodisperse polystyrene solutions. Compute the molecular weight of a singe (1), polystyrene (PS) repeat unit. ... energy extracted from the temperature shift in the relaxation spectra corresponded to the motion of a statistical unit (Kuhn's segment) in polystyrene. (b) Compute the number-average molecular weight for a polystyrene for which the degree of polymerization is 25,000. In this study, synchrotron X-ray scattering and quantitative data analysis were performed on a series of 33-armed polystyrenes with four different arm… (b) Compute the number-average molecular weight for a polystyrene for which the degree of polymerization is 25,000. Compute the repeat unit molecular weight of polystyrene. Compute the repeat unit molecular weight of polystyrene and the number-average molecular weight of the material if the degree of polymerisation is 25000. Ionization Techniques • MALDI – Typically ... – Ag and Cu with polystyrene polyisoprene etc. (b) Compute the number-average molecular weight for a polystyrene for which the degree of polymerization is 25,000. CHE 253 Homework #5--solution Due Date: February 26, 2014 4.4 (a) Compute the repeat unit molecular weight of polystyrene. You are right. Reinhard Kniewske, Werner‐Michael Kulicke, Study on the molecular weight dependence of dilute solution properties of narrowly distributed polystyrene in toluene and in the unperturbed state, Die Makromolekulare Chemie, 10.1002/macp.1983.021841021, 184, 10, (2173-2186), (2003). (a) From Equation 14.6, the average repeat unit molecular weight of the copolymer, m calculated as:, is DP From Table 14.5, the butadiene repeat unit contains 4 Carbon atoms and 6 Hydrogen atoms. • Molecular Weight Distribution – Mn - Number Average – Mw - Weight Average – Pd - Polydispersity • Repeat Unit Mass – Repeat Unit Molecular Formula • End Group Mass – End Group Molecular Formula. (b) Compute the number-average molecu- lar weight for a polypropylene for which the degree of polymerization is 15,000. The repeat unit for polystyrene (table 14. 14. 14.5 Below, molecular weight data for a poly- tetrafluoroethylene material are tabulated. (b) Compute the number-average molecular weight for a… Get the answers you need, now! 14.4 (a) Compute the repeat unit molecular weight of polypropylene. (b) Compute the number-average molecular weight for a polystyrene for which the degree of polymerization is 25,000. 3) has eight carbon atoms and eight hydrogen atoms. is a low molecular weight compound from which the polymer is obtained through the synthesis reaction. 104.4 g/mol Compute the degree of polymerization for a polystyrene (PS) polymer with a number-average molecular weight … General-purpose polystyrene is clear, hard, and rather brittle. Solution 4.4 (a) The repeat unit molecular weight of polypropylene is called for in this portion of the problem. Answer b: MW = 200 units x 72.06 Da/unit + 2 Da = 14,412 Da (based on 200 simple repeating units, but this is a complicated case. 104. b. (a) Compute the repeat unit molecular weight of polystyrene. molecular weight of polymer (g/mol) 12,000 g/mol DP molecular weight of mer (g/mol/mer) 226 g/mol/mer ===53 mers 7.4 An injectionŒmolding polycarbonate material has an average molecular weight of 25,000 g/mol. Polyvinylidine fluoride is usually made using emulsion polymerization. (a) Compute the repeat unit molecular weight of polystyrene. We are asked to compute the degree of polymerization for polystyrene, given that the number- average molecular weight is 500,000 g/mol. About Polystyrene; 1 cubic meter of Polystyrene weighs 1 060 kilograms [kg] 1 cubic foot of Polystyrene weighs 66.17364 pounds [lbs] Polystyrene weighs 1.06 gram per cubic centimeter or 1 060 kilogram per cubic meter, i.e. However, a detailed understanding of the cause of this effect is lacking. Polystyrene can be solid or foamed. Select one: a. A . m n= M = 350, 000 g/mol 4425 = 79.10 g/mol Thus, the molecular weight of the butadiene repeat unit is : … For polystyrene, from Table 14.3, each repeat unit … is a molecular structure, defined by the monomer, constituting part of the repeating unit. 100 repeat units per polymeric chain with an average . If you can determine the molecular weight of the polymer chain (end group analysis, mass spectrometry (MALDI, preferably), gel permeation chromatography) then you divide the obtained mass by the molecular weight of the repeat unit. The effect of nanoconfinement on the glass transition temperature (T g) of supported polystyrene (PS) films is investigated over a broad molecular weight (MW) range of 5000-3 000 000 g/mol. monomer. (a) Compute the repeat unit molecular weight of polystyrene. Solution (a) The repeat unit molecular weight of polystyrene is called for in this portion of the problem. Solution (a) The repeat unit molecular weight of polystyrene is called for in this portion of the problem. When drawing one, you need to: Polystyrene (PS) / ˌ p ɒ l i ˈ s t aɪ r iː n / is a synthetic aromatic hydrocarbon polymer made from the monomer known as styrene. The effect of nanoconfinement on the glass transition temperature (Tg) of supported polystyrene (PS) films is investigated over a broad molecular weight (MW) range of 5000−3 000 000 g/mol. Solid polystyrene is transparent, owing to these large, ring-shaped molecular groups, which prevent the polymer chains from packing into close, crystalline arrangements. The structure of the polymer repeating unit can be represented as: The presence of the pendant phenyl (C 6 H 5) groups is key to the properties of polystyrene. Solution (a) The repeat unit molecular weight of polystyrene is called for in this portion of the problem. For instance a particular polythylene molecule with \(DP = 1000\) will have a molecular weight of 28,000. It is defined also as monomer or monomeric unit, but not always in the correct way. It is an inexpensive resin per unit weight. Polystyrene 19K (5 mg/mL in THF) MALDI micro MX spec-trum. molecular weight of ... a function of polystyrene molecular weight (P w) . Polystyrene average Mw 35,000; CAS Number: 9003-53-6; Synonym: PS; Linear Formula: [CH2CH(C6H5)]n; find Sigma-Aldrich-331651 MSDS, related peer-reviewed papers, technical documents, similar products & more at Sigma-Aldrich. 260. c. 401. d. 2600. e. 13. (Use Table 4.3 in text book for mer structure.) Compute the degree of polymerization. (See Sec. The repeat unit molecular weight of polypropylene is just. 14.3 The number-average molecular weight of a polystyrene is 500,000 g/mol. The particular molecule contains 5.35 x 10 3 of repeat units. M.W. The molecular weight of a particular polymer molecule is a product of the degree of polymerization and the molecular weight of the repeating unit. Calculate its degree of polymerization. Similarly one may ask, how do you find the number of repeat units? 5.4 (a) Compute the repeat unit molecular weight of polystyrene. 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