Molecular mass number fraction

In POLYM the output data of KINREL are used with compositional information to calculate the number and mass average molecular masses (Rn and Rm, respectively) and number and end-group average functionalities (fp and fg> respectively) in the pre-gel region in all stages. In addition, the network characteristics such as sol fraction, mj, and the number of elastically active network chains per monomer (5), Ng, are calculated in the post-gel regime of stage 3. 

Figure 3 Size fractionation of EDTA-soluble polyuronides from Rutgers and transgenic fruit juice processed by cold- and hot-break methods. Pectin from processed juice was extracted as ethanol-insoluble solids and size fractionated on a Sepharose CL4B column. Under the same chromatographic conditions, elution of the branched dextrans with average molecular mass 2000, 500, 252, 151, 40 and 17.7 kD-peaked in fraction number 46, 50, 54, 62, 67 and 72, respectively. Modified from Thakur et al. [23].

Now the function displays the number fraction of molecules with a certain molecular mass. Its integral is 1 by definition. Nevertheless, we still call it the number molecular weight distribution because the factor /N (A/) dM is nothing but a constant. 

Mark-Houwink-Sakurada constant Mass transfer coefficient around gel Fractional reduction in diffusivity within gel pores resulting from frictional effects Solute distribution coefficient Solvent viscosity nth central moment Peak skewness nth leading moment Viscosity average molecular weight Number of theoretical plates Dimensionless number... 

They studied the effect of the mass detectors drift tube temperature on the low-molecular-mass TGs. Solutions of 10 mg/ml of tributyrin, tricaproin, tricaprylin, tricaprin, and trilaurin were injected twice at each of the following drift tube temperatures 20,25, 30,45, and 60°C. Five replications of the HPLC analysis were performed for one sample of ewe s milk fat to determine the reproducibility of the HPLC method. The TG composition was estimated in accordance with the method based on the calculation of the equivalent carbon numbers (ECNs) of the HPLC chromatographic peaks and in the molar composition in fatty acids, analyzed by GLC, collected at the HPLC chromatograph outlet. The HPLC fractions were collected every 40 s at the outlet of the column after 14 min there were no peaks before that time. 

In chemistry we have traditionally expressed the amount of a substance i in a system of substances in terms of the number of moles nt - mi/Mi instead of its mass mt, where M denotes the gram molecular mass of the substance i. The composition of the system of substances is expressed accordingly by the molar fraction xt as defined in Eq. 1.1 ... 

Low Voltage Mass Spectrometry. The nominal parent mass numbers of the various components in the low molecular weight extractable fractions obtained from polyoctenamer and poly-1,5-octadienamer are listed in Table I. Quantitative estimation of the relative amounts of individual components were not carried out owing to experimental difficulties. The large variation in the volatilities of the various oligomers limits this procedure to the determination of molecular weights of the oligomers. 

Several authors [3-9] studied the solubility of polymers in supercritical fluids due to research on fractionation of polymers. For solubility of SCF in polymers only limited number of experimental data are available till now [e.g. 4,5,10-12], Few data (for PEG S with molar mass up to 1000 g/mol) are available on the vapour-liquid phase equilibrium PEG -CO2 [13]. No data can be found on phase equilibrium solid-liquid for the binary PEG S -CO2. Experimental equipment and procedure for determination of phase equilibrium (vapour -liquid and solid -liquid) in the binary system PEG s -C02 are presented in [14]. It was found that the solubility of C02 in PEG is practically independent from the molecular mass of PEG and is influenced only by pressure and temperature of the system. 

This result was obtained by Maxwell in 1860 and is called the Maxwell s distribution of molecular velocities. It is customary to writep(c)dcas dNIN, where /Vis the total number of gas molecules. The quantity dN/Nor p(c)dc gives the fraction of molecules with speeds between c and c + dc. The molecular mass m = Mn/NA where Mm is the molar mass and NA is the Avogadro number. Accordingly, Eq. 3.7 may also be written as... 

This generic name is commonly, but improperly, used to designate a family of copolymers obtained from unsaturated hydrocarbons of petroleum refinery C4 fractions, and the products obviously must not be confused with the crystalline isotactic 1-polybutene obtained through Ziegler-Natta catalysis. The commercial polybutenes are clear, water-white, odorless, oily to highly viscous liquids, with number-average molecular masses ranging from about 300 to 2500. 

The origin of mass-dependent fractionation (MDF) in isotope systems lies in the mass dependence of the molecular properties (e.g., zero-point energy) and physical processes (e.g., evaporation) affecting the compound. If a compound comprised of atoms with 3 or more stable isotopes, such as oxygen or sulfur, deviates from a mass-dependent relationship, the compound is said to exhibit mass-independent fractionation (MIF). MIF signatures are not affected by mass-dependent processes, and so are excellent tracers of the small number of mass-independent processes that exist in nature. 

Here, AH is in kJ - kg , MW is the molecular mass of the monomer xmit, m is the numbOT of moles of products formed in the stoichiometrically complete combustion of the polymer, and m is the number of nitrogen moles in the Oj/Nj atmosphere, per 1 mol of monomer unit. LOI is given as molar oxygen fraction in the atmosphere. 

The fact that a viscosity increase after phase segregation (for t > tp) is connected with such mechanism is evidenced by the results of gel chromatographic (GPC) analysis of solfi action in the network formation process of low-molecular siloxane rubbers (Fig. 15). As the reaction proceeds the molecular mass of the sol fraction decreases and so does its viscosity. However, network formation of a number of epoxy resins cured with amines or other curing agents conform the homogeneous model without microgel formation [88 a]. 

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