Non-volatile solvent

It was pointed out in Chapter 5 that plasticisers were essentially non-volatile solvents. Consequently they were required to have solubility parameters close to that of the polymer and a molecular weight of at least 300. If the polymer or the plasticisers had a tendency to crystallise then there would need to be some sort of specific interaction between the polymer and the plasticiser. Tables 5.4 and 5.6 gave some figures for the solubility parameters of polymers and plasticisers. 

As explained in Chapter 5, these materials are essentially non-volatile solvents for PVC. Because of their molecular size they have a very low rate of diffusion into PVC at room temperature but at temperatures of about 150°C molecular mixing can occur in a short period to give products of flexibility varying according to the type and amount of plasticiser added. 

Being slightly crystalline, there are few good solvents, the best known of which are nitrobenzene, cyclohexanone and tetrahydrofuran. When mixed with certain non-volatile solvents such as some phthalates, adipates and phosphates, flexible materials are obtained and which are referred to as plasticised p. v.c. 

If the process requirement is to strip a volatile component from a relatively non-volatile solvent, the rectifying section may be omitted, and the column would then be called a... 

If a non-volatile solvent, such as glacial acetic acid, xylene, high-boiling petrol ether, or nitrobenzene, has been used for recrystallisation, it is washed out before drying by means of one which is more easily removed, e.g. ether, benzene, petrol. In general a substance which is sparingly soluble in glacial acetic acid or nitrobenzene is so... 

Until recently, the idea of a recyclable, non-volatile solvent seemed like the stuff of science fiction. But in the 1980s, researchers in the United States were trying to create a new electrolyte for batteries. Instead, they created a colourless, odorless liquid that was composed of nothing but ions—an ionic liquid. 

In a related study this group also demonstrated the use of non-volatile solvents in CEC-MS without compromising the quality of spectra that has also been demonstrated using polymer-based monolithic column prepared by in situ copolymerization of butyl methacrylate with sulfonic acid functionalities. 

The formulae of the most important non-volatile solvents are given below. All of them are characterized by the presence of carbonyl groups and with the exception of camphor by the presence of the amido group —CO—N< ... 

Individual non-volatile solvents vary in their capacity for dissolving nitrocellulose. The type of nitrocellulose dissolved is also a factor to be considered. Marqueyrol and Florentin [34] report the following figures which denote the amount of solvent required to obtain a uniform gelatinous film (Table 184). 

Davis [25] found that non-volatile solvents vary in their capacity for gelatinizing nitrocellulose, depending on the liquid in which they are dissolved. The following data show the gelatinizing power of pyrocollodion cotton (Table 185). The figures indicate the parts of non-volatile solvent required for the complete gelatinization of 100 parts of pyrocollodion cotton. 

Ability to completely gelatinize pyrocollodion cotton OF VARIOUS NON-VOLATILE SOLVENTS, ACCORDING TO DAVIS [25]... 

Solventless powder is usually tubular. It was first produced at the Diineberg factory, in 1912, under the name of RPC/12 (Rohrenpulver mit Centralit 1912). Initially the manufacture of this powder was based upon the use of easily soluble nitrocellulose (11 % N), plus guncotton to bring the total nitrogen content up to 11.7%. About 25% nitroglycerine was used plus a large quantity of centralite (4-5%) as a non-volatile solvent. 

In the U.S.S.R. a type of solventless powder was introduced in which organic nitro compounds, e.g. DNT, partly replaced the nitroglycerine. DNT acts as a non-volatile solvent and as a stabilizer. Since it also reduces the heat of explosion these powders are either flashless or partly so. 

BIOS/JAP/PR/1292/Report. Japanese Propellants—Research on Non-volatile Solvent Powders, H.M.S.O., London. 

Non-volatile solvents are usually called gelatinizers (or plasticizers in plastics technology). 

The process of dissolving nitrocellulose fibres in non-volatile solvents, that are commonly used in small quantities to bring about the transition of nitrocellulose fibres in a solubilized state, is often called gelatinization. 

The process for the manufacture of ball-grain powder which Olsen and his co-workers have devised 26 combines nicely with Olsen s process for the quick stabilization of nitrocellulose to form a sequence of operations by which a finished powder may be produced more rapidly and more safely than by the usual process. It supplies a convenient means of making up a powder which contains non-volatile solvents throughout the mass of the grains or deterrent or accelerant coatings upon their surface. 

Non-volatile solvents eliminate the health and environmental risks associated with the use of volatile solvents, but may pose their own risks and separation problems. Several liquid polymers, such as PEG, poly(propylene glycol) (PPG), poly(tetrahydrofuran) (PTHF), Polydimethylsiloxane (PDMS), poly(methylphenyl siloxane) (PMPS), and variations of those with ether or ester end-capping groups, are compared in terms of environmental risk, solvent polarity, and performance as... 

Stinchcomb, A.L., Pirot, F., Touraille, G.D., Bunge, A.L., and Guy, R.H., Chemical uptake into human stratum corneum in vivo from volatile and non-volatile solvents. Pharm. Res. 16, 1999, 1288-1293. 

Fast atom bombardment the sample in solution in a non-volatile solvent such as glycerol is ionized under vacuum by bombardment with accelerated neutrals such as argon. 

Properties White, pulped fibers. 12.6 per cent nitrogen. Soluble in ether-alcohol (2 1) and in acetone. Less corrosive on bore of gun than guncotton. For conversion to smokeless powder it is colloided with volatile solvents with or without addition of some non-volatile solvents. 

However, in 1972, one year before Manassen s and Joo s first publications, Parshall working at Dupont in Delaware reported that the hydrogenation and alkoxycarbonylation of alkenes could be catalysed by PtCL when dissolved in tetraalkylammonium chloride/tin dichloride at temperatures of less than 100°C/5] It was even noted that the product could be separated by decantation or distillation. Parshall recognised the separation problem associated with homogeneous catalysis and in this paper states, An approach that seems under utilised is the use of molten salts as stable, non-volatile solvents from which organic products are readily separated by distillation. .. or decantation . An even earlier report by a group working for the U S. 

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