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R1 is depending on the bifunctional initiator used for the polymerization. In the current case the Tosyl-function can serve all these purposes.Īs the polymer is terminated at both ends with the Tosylgroup the number of protons that needs to be considered is 2×4 = 8, hence the Mn of the polymer can be calculated as follows.įigure 2: 1D 1H spectra of poly(ε-caprolactone) end functionalized with a tosyl group on each chain end (calculated DP of 36, molecular weight of 4100 g/mol) acquired on a Spinsolve 60 MHz. Functional groups are introduced specifically for the molecular weight determination or for the dedicated synthesis of copolymers and/or post functionalization. This is very important, because it means that one can remove the effects of the context transition by using ALL as a filter argument. 2) polymer, which is functionalized with a Tosyl end group at both ends. CALCULATE evaluates the CALCULATE modifiers used in filter arguments: USERELATIONSHIP, CROSSFILTER, ALL, ALLEXCEPT, ALLSELECTED, and ALLNOBLANKROW. The second example exhibits a poly ε-caprolactone (Fig. The two signals can be integrated and the degree of polymerization as well the molecular weight can be obtained by using the equations described above.įigure 1: 1D 1H spectra of polyethylene glycol (PEG)with a methoxy group acquired on a Spinsolve 80 MHz system. The strong signal at 3.7 ppm originates from the CH 2 groups, while the signal at 3.4 ppm originates from the methoxy end group. This polymer, also known as polyethylene oxide, is commercially available and finds applications in pharmaceutical, medical, cosmetics, and food. The first graph shows a 1H spectrum measured on Spinsolve 80 MHz system of a methoxy terminated polyethylene glycol (PEG) spectrum. Typically, the molecular weight of the end group is not taken into consideration for the calculation as it is usually negligible compared to the total molecular weight of the polymer chains. A - Compound (Blue and red) B - Element (Blue only) Na. Classify each of the samples of matter according to type as indicated. 3) There are many more known compounds than elements. 2) Elements and compounds are both pure substances. The molecular weight of the polymer can then easily be determined by multiplying the DP with the molecular weight of the repeating unit. 1) A compound contains two or more different elements. The degree of polymerization (DP), or number of repeating units, can be determined by comparing in the 1D 1H spectra the integral of the end-group and the integral of the repeating chain unit of interest by using this equation: One of the main parameters determining the properties of a polymer is the degree of polymerization which is directly related to the molecular weight.