T able 8.7 Molecular Weights of PET Samples . Select one: a. (a) 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. (b) Compute the number-average molecular weight for a polystyrene for which the degree of polymerization is 25,000. You are right. (b) Compute the number-average molecular weight for a polypropylene for which the degree of polymerization is 15,000. In this study, synchrotron X-ray scattering and quantitative data analysis were performed on a series of 33-armed polystyrenes with four different arm… 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. Solution (a) The repeat unit molecular weight of polystyrene is called for in this portion of the problem. 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. 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. 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. 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. Problem 4.4 (a) Compute the repeat unit molecular weight of polypropylene. Expert Answer 100% … Solution 4.4 (a) The repeat unit molecular weight of polypropylene is called for in this portion of the problem. 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. It is an inexpensive resin per unit weight. (b) Compute the number-average molecular weight for a polystyrene for which the degree of polymerization is 25,000. Similarly one may ask, how do you find the number of repeat units? (b) Compute the number-average molecu- lar weight for a polypropylene for which the degree of polymerization is 15,000. 14.5 Below, molecular weight data for a poly- tetrafluoroethylene material are tabulated. • … 100 repeat units per polymeric chain with an average . 14.4 (a) Compute the repeat unit molecular weight of polypropylene. This can be accounted for by the molecular weight dependence of the density of repeat units of a polymer coil in solution. 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. 14. Calculate its degree of polymerization. (Use Table 4.3 in text book for mer structure.) The repeat unit for polystyrene (table 14. Polystyrene MW is shown to have no significant impact on the film thickness dependence of Tg − Tg,bulk. For M.W. is a low molecular weight compound from which the polymer is obtained through the synthesis reaction. We are asked to compute the degree of polymerization for polystyrene, given that the number- average molecular weight is 500,000 g/mol. You need to know the number of repeat units in the chain and multiply the monomer molecular weight by that number. 5.4 (a) Compute the repeat unit molecular weight of polystyrene. The molecular weight is the sum of the weights of all the repeat units plus the weight of the end groups. Ionization Techniques • MALDI – Typically ... – Ag and Cu with polystyrene polyisoprene etc. Polystyrene 19K (5 mg/mL in THF) MALDI micro MX spec-trum. A . m n= M = 350, 000 g/mol 4425 = 79.10 g/mol Thus, the molecular weight of the butadiene repeat unit is : … 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. is a molecular structure, defined by the monomer, constituting part of the repeating unit. 104.4 g/mol Compute the degree of polymerization for a polystyrene (PS) polymer with a number-average molecular weight … 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. Compute the repeat unit molecular weight of polystyrene. It is defined also as monomer or monomeric unit, but not always in the correct way. 3 the number-average molecular weight of a polystyrene is 500,000 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 General-purpose polystyrene is clear, hard, and rather brittle. For a polystyrene solution with a bimodal molecular weight distribution, the coefficient A is smaller than for either of the monodisperse polystyrene solutions. 3) has eight carbon atoms and eight hydrogen atoms. (See Sec. For polystyrene, from Table 14.3, each repeat unit … Solution (a) The repeat unit molecular weight of polystyrene is called for in this portion of the problem. Solid polystyrene is transparent, owing to these large, ring-shaped molecular groups, which prevent the polymer chains from packing into close, crystalline arrangements. (b) Compute the number-average molecular weight for a polystyrene for which the degree of polymerization is 26,000. ... energy extracted from the temperature shift in the relaxation spectra corresponded to the motion of a statistical unit (Kuhn's segment) in polystyrene. 104. b. Polystyrene can be solid or foamed. (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. 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). The repeat unit molecular weight of polypropylene is just. Compute the repeat unit molecular weight of polystyrene and the number-average molecular weight of the material if the degree of polymerisation is 25000. Formula to Calculate Number Average Molecular Weight. MW = 1,000 units x 104.15 Da/unit + 2 Da = 104,152 Da. (a) Compute the repeat unit molecular weight of polystyrene. Compute the molecular weight of a singe (1), polystyrene (PS) repeat unit. 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. The molecular weight of a particular polymer molecule is a product of the degree of polymerization and the molecular weight of the repeating unit. m = 3(AC) + 6(AH) = (3)(12.01 g/mol) + (6)(1.008 g/mol) = 42.08 g/mol. 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. monomeric unit. However, a detailed understanding of the cause of this effect is lacking. monomer. 260. c. 401. d. 2600. e. 13. (a) Compute the repeat unit molecular weight of polystyrene. Polyvinylidine fluoride is usually made using emulsion polymerization. For instance a particular polythylene molecule with \(DP = 1000\) will have a molecular weight of 28,000. (b) Compute the number-average molecular weight for a… Get the answers you need, now! CHE 253 Homework #5--solution Due Date: February 26, 2014 4.4 (a) Compute the repeat unit molecular weight of polystyrene. • 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. Its molecular weight can be as high as 5 × 10 6. 7.7 for the mer structure of polycarbonate.) 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). 14.3 The number-average molecular weight of a polystyrene is 500,000 g/mol. Students also viewed these Thermodynamics questions molecular weight of ... a function of polystyrene molecular weight (P w) [28]. Compute the repeat unit molecular weight of polystyrene. (b) Compute the number-average molecular weight for a polystyrene for which the degree of polymerization is 25,000. 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. Solution (a) The repeat unit molecular weight of polystyrene is called for in this portion of the problem. (b) Compute the number-average molecular weight for a polystyrene for which the degree of polymerization is 25,000. 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