Molecular weight volume

Molecular weight Volume percent of solids Fire hazard only... 

A fourth approach is to seek reported experimental data for substances similar in chemical class or structure to the substance of interest exploiting the data base listed earlier and develop a simple structure property relationship for this specific class, using molecular weight volume as a descriptor. This approach is likely to be fairly accurate, provided the original data are accurate. 

The reversion of gelatins to collagen has also been discussed with refer ence to cross-links. The denaturation of collagen results in marked changes of viscosity, optical rotation, molecular weight, volume, kinetics of proteolysis, and other properties. Under certain conditions a partial reversal of these changes can be achieved (Flory and Garrett, 1958 von Hippel... 

The steiic attributes of a molecule include its size and shape. Molecular size or bulk is easily assessed from properties such as molecular weight, volume, or surface area. A summary of parameters for molecular bulk is provided by Livingstone (2000). Molecular shape is much more difficult to parameterize, and there is no single descriptor capable of doing so (Patel and Cronin, 2001b). Different aspects of molecular shape, such as chirality, linearity, and branching, are often addressed individually (Livingstone, 2003). 

Compound Molecular weight Volume of stock solution evaporated (pL) Vehicle ... 

If the polymer chains are linear, there is a direct relationship between molecular weight, volume in solution and elution time for a given polymer type. This relation is used to create a calibration curve relating elution time to molecular weight. In addition, the universal calibration curve can be used to extend this relation to linear polymers of aU types, provided that the relation between intrinsic viscosity and molecular weight of the polymer is known (using, for instance, the Mark-Houwink equation) or measured using an on-line viscometer (GPC/RI-VISC). 

Amphiphilic block copolymers self-assemble in selective solvents such as water. Depending on parameters like overall average molecular weight, volume fraction of each block, or effective interaction energy between monomers in the blocks, vesicles with a bilayer shell and a solvent interior volume similar to liposomes are formed. They are often called polymersomes [241]. Such polymersomes in aqueous media have attracted increasing interest due to their enhanced stability compared to classical liposomes and due to the potential to control vesicle properties like bilayer thickness, permeability, or surface functionalities by appropriate chemical copolymer adjustment [242]. 

This chapter serves as an introduction to the origin of nonuniform latex particles. First, a brief discussion of the seeded emulsion polymerization technique that has been widely used to prepare composite polymer particles with a variety of morphological structures is given. This is followed by the illustration of the effects of important factors such as initiators, monomer addition methods, polymer molecular weight, volume ratio of the second-stage monomer to the seed polymer, and polymerization temperature that affect the morphological structures of latex particles. The development of morphological structures of nonuniform latex particles will then be covered at the end of this chapter. 

Viscosity additives are aliphatic polymers of high molecular weight whose main chain is flexible. It is known that in a poor solvent, interactions between the elements making up the polymer chain are stronger than interactions between the solvent and the chain (Quivoron, 1978), to the point that the polymer chain adopts a ball of yarn configuration. The macromolecules in this configuration occupy a small volume. The viscosity of a solution being related to the volume occupied by the solute, the effect of polymers on the viscosity in a poor solvent will be small. 

The volume fraction would typically be used to represent the make up of a gas at a particular stage in a process line and describes gas composition e.g. 70% methane and 30% Ethane (also known as mol fractions) at a particular temperature and pressure. Gas composition may also be expressed in mass terms by multiplying the fractions by the corresponding molecular weight. 

Volume (or mol) fraction Molecular Weight (g/mol) Weight Composition... 

This observation that the length of the hydrocarbon chain could be varied from 16 to 26 carbon atoms without affecting the limiting area could only mean that at this point the molecules were oriented vertically. From the molecular weight and density of palmitic acid, one computes a molecular volume of 495 A a molecule occupying only 21 A on the surface could then be about 4.5 A on the side but must be about 23 A long. In this way one begins to obtain information about the shape and orientation as well as the size of molecules. 

Fig. XI-7. Volume fraction profile of 280,000-molecular-weight poly(ethylene oxide) adsorbed onto deuterated polystyrene latex at a surface density of 1.21 mg/m and suspended in D2O, from Ref. 70.

Tlie molecular volume Vm can in turn be obtained by dividing the molecular weight by density or from refractivity measurements is Avogadro s number. The cavity radius (... 

The excess of unchanged acetic anhydride is then hydrolysed by the addition of water, and the total free acetic acid estimated by titration with standard NaOH solution. Simultaneously a control experiment is performed identical with the above except that the alcohol is omitted. The difference in the volumes of NaOH solution required in the two experiments is equivalent to the difference in the amount of acetic add formed, i.e., to the acetic acid used in the actual acetylation. If the molecular weight of the alcohol is known, the number of hydroxyl groups can then be calculated. 

A number of properties can be computed from various chemical descriptors. These include physical properties, such as surface area, volume, molecular weight, ovality, and moments of inertia. Chemical properties available include boiling point, melting point, critical variables, Henry s law constant, heat capacity, log P, refractivity, and solubility. 

Dimerization in concentrated sulfuric acid occurs mainly with those alkenes that form tertiary carbocations In some cases reaction conditions can be developed that favor the formation of higher molecular weight polymers Because these reactions proceed by way of carbocation intermediates the process is referred to as cationic polymerization We made special mention m Section 5 1 of the enormous volume of ethylene and propene production in the petrochemical industry The accompanying box summarizes the principal uses of these alkenes Most of the ethylene is converted to polyethylene, a high molecular weight polymer of ethylene Polyethylene cannot be prepared by cationic polymerization but is the simplest example of a polymer that is produced on a large scale by free radical polymerization... 

Example Sulfuric acid has the molecular weight 98.08. If the concentrated acid assays 95.5% and has the specific gravity 1.84, the volume required for 1 liter of a 0.1 molar solution is... 

Accordingly, the product 6A is about the same as Vj, the volume of the hole. For liquids of low molecular weight, is on the order of 0.5% the volume of the liquid at room temperature, increasing to 2-3% at the boiling point, and larger yet at still higher temperatures. This identification makes 6 A easier to visualize, but it still leaves us with four parameters kj, 6, X, and. ... 

Comparing this result with Eq. (3.1) shows that the quantity in brackets equals Young s modulus for an ideal elastomer in a perfect network. Since the number of subchains per unit volume, i /V, is also equal to pN /Mj, where M, is the molecular weight of the subchain, the modulus may be written as... 

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