Molecular weight calculating

The effect of different end groups on M can be seen by comparing the true molecular weight with an approximate molecular weight, calculated on the basis of a formula (CH2)n + 2- T se M s and the percentage difference between them are listed here for several values of n ... 

Note that the method of end group analysis is inapplicable to copolymers, since the presence of more than one repeat unit adds extra uncertainty as to the nature of chain ends. The above example included the remark that the molecular weights calculated in the example were average values. In the next section we shall examine this point in greater detail. 

The molecular weights calculated in this way agree very closely with the so-called chemical molecular weights, derived from chemical analysis, and the method therefore rivals the latter in accuracy, without the attendant complications attaching to chemical operations with pure substances. 

The molecular weight calculated for gelatin is 333,000g/mol. The value of a given at different temperatures shows that this biopolymer in aqueous solution behaves in a conformation predominantly confined to the rod-like, different as observed by Bohidar 1998. 

Partitioning or cell-based methods provide an absolute measure of the chemical space covered by a collection of compounds. They are based on the definition of a low-dimensional chemistry space, for example, one based on a small number of physicochemical properties such as molecular weight, calculated logP, and number of hydrogen bond donors [45]. Each property defines an axis of the chemistry-space. The range of values for each property is divided into a set of bins, and the combinatorial product of all bins then defines the set of cells or partitions that make up the space. 

A new direct method for using size exclusion chromatography (SEC) to evaluate polymer intrinsic viscosity [n] is discussed. Sample viscosity information is obtained by combining SEC elution curve data and calibration data using direct SEC-[n] calibration procedures without involving polymer molecular weight calculations. The practical utility, convenience and the expected precision of the proposed method are illustrated. 

Table III. Molecular Weight Calculations on NOnionic PAM Standards - Polyethylene Oxide in Mobile Phase. ...

Molecular weight calculated on the basis of one carbonyl and four methoxyl groups per lignin unit. 

Note use 0.1035 m to do the molecular weight calculation, remembering there are only 2 significant figures.)... 

Single crystal x-ray diffraction studies showed that the crystals of halcinonide recrystallized from tz-propyl alcohol-water azeotrope (79 22) are orthorhombic and belong to the gpace group P2 2 2, with unit ell constants of a = 10.007 A, = 11.875 A ana Q = 19.460 A. Density is 1.330 gm/cm2 3, as measured by flotation in a hexane-carbon tetrachloride gradient. The molecular weight calculated from the unit cell volume and density is 461 daltons (theoretical is 455 daltons). 

Hence, is the statistics average Molecular weight calculated from the number Molecular weight distribution function, N(M). Mn is the statistical average Molecular weight calculated from the weight... 

This chapter describes the use of AFM as a methodology for characterizing dendritic macromolecules and their self-assembled films. Systematic AFM studies of the PAMAM dendrimers properties (e.g. their size, shape, rigidity, packing textures and molecular weight calculations) will be fully addressed in this chapter. 

Table 12.1 Comparison of the mean molecular weight calculated by AFM and theoretical molecular weight of PAMAM dendrimers...

Based on the same equation (1), absolute molecular weight of tecto-de-ndrimers could be calculated. The results shown in Table 12.3 clearly demonstrate that the molecular weights calculated from the AFM images of individual molecules are very close to those obtained by the more classical MALDI-TOF MS and PAGE techniques. 

Alfredson, T.V., Perry W.J., and Tallman, L., Automated GPC Data Handling for Molecular Weight Calculations of Polymers, paper presented at 1982 Pittsburgh Conference and Exposition on Analytical Chemistry and Applied Spectroscopy, March 1982, Atlantic City, NJ. 

Selected entries from Methods in Enzymology [vol, page(s)] Association constant determination, 259, 444-445 buoyant mass determination, 259, 432-433, 438, 441, 443, 444 cell handling, 259, 436-437 centerpiece selection, 259, 433-434, 436 centrifuge operation, 259, 437-438 concentration distribution, 259, 431 equilibration time, estimation, 259, 438-439 molecular weight calculation, 259, 431-432, 444 nonlinear least-squares analysis of primary data, 259, 449-451 oligomerization state of proteins [determination, 259, 439-441, 443 heterogeneous association, 259, 447-448 reversibility of association, 259, 445-447] optical systems, 259, 434-435 protein denaturants, 259, 439-440 retroviral protease, analysis, 241, 123-124 sample preparation, 259, 435-436 second virial coefficient [determination, 259, 443, 448-449 nonideality contribution, 259, 448-449] sensitivity, 259, 427 stoichiometry of reaction, determination, 259, 444-445 terms and symbols, 259, 429-431 thermodynamic parameter determination, 259, 427, 443-444, 449-451. 

Molar mass, relative molecular mass, or molecular weight calculated from experimental data without the application of appropriate corrections, such as for finite polymer concentration, association, preferential solvation, compositional heterogeneity, constitutional heterogeneity. 

For characterization, the polymer is dissolved in methylene chloride, precipitated again in methanol and dried at 50 °C in vacuum.The limiting viscosity number is determined in tetrahydrofuran at 20 °C and the molecular weight calculated (see Sect. 2.3.3.3.1). Additional information can be obtained by infrared spectroscopy.There should be no absorption of the OH-group at -3400 cm . 

Table 13.1 Top section The mean value of descriptors. Model PC uses physicochemical molecular weight, calculated LogP and target hit based descriptors. Bottom section Sensitivity and rate for compounds originating from different specificity of promiscuous models applied to the disease areas. Middle section Sensitivity and drugs set. Model FP uses fingerprint based specificity of promiscuous models applied to descriptors. Model PC uses physicochemical the test set. Model FP uses fingerprint based based descriptors.

In a particular sample of a polymer, 100 molecules have molecular weight 10 each, 200 molecules have molecular weight 10 each and 200 molecules have molecular weight 10 each. The number-average and weight average molecular weight, calculated ... 

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