Molecular weight types

Neoprene WHV-A. It is a non-peptizable and mercaptan-modified polychloro-prene elastomer. It is a slow-crystallizing, high molecular weight type and contains only 85% trans-, 4 structure. It is generally used in blends with low molecular weight crystallizing polychloroprene types to increase solution viscosity. 

FIGURE 20.6 DRI chromatograms of partially hydrolyzed PVA (low molecular weight type) using TSK-PW columns. 

In the gas phase species are isolated, far from each other. It follows that their behaviour is not influenced by solvation, as occurs in solution, or by reticular forces, as in the crystalline state. Thus, the gas phase allows the study of the intrinsic properties of a given species, that are only dependent on its chemico-physical properties, i.e. its molecular weight, type of atoms (C, N, O,...) involved, connections between them, etc. 

In particular, EVA waxes refer generally to oligomeric polymer compounds. They are prepared by the copolymerization of ethylene monomers and vinyl acetate monomers in the same way as the high molecular weight types. 

Surfactant Classification Average Molecular Weight Type... 

PAHs can be further categorized as low and high molecular weight types (LMW and HMW) since the distribution and transport patterns of the two groups are distinct due to vapor pressure differences. 

A5. Agnello, V., Koffler, D., Eisenberg, J. W., Winchester, R. J., and Kunkel, H. G., Clq precipitins in the sera of patients with systemic lupus erythematosus and other hypo-complementemic states Characterization of high and low molecular weight types. J. Exp. Med. 134, 228s-241s (1971). 

Varies in molecular weight from n = 2 to 7. Higher-molecular-weight types provide greater flexibility. 

Instruction E. Product 17. The following substances are used in the process of Instruction B 35 kg. Levapren 450 115 kg. vinyl chloride 150 kg. water plus 1.5 kg. methyl cellulose 50 grams azodiisobutyronitrile. Polymerization is carried out for 13 hours at 61 °C. The bead polymer obtained has a PVC content of 73%. Product 16 was made according to Instruction E, using a low molecular weight type of Levapren (molecular weight ca. 3 X 104, 43.5% vinyl acetate). The bead polymer obtained has a PVC content of 75%. 

Separating a whole sample of a coal liquid or shale oil into classes poses special problems since these materials contain high concentrations of heteroatomic species compared with natural petroleums. Many of these compounds are quite polar and can cause emulsification, precipitation, and may even react to produce artifactual compounds at some stage during a separation procedure. Many liquid chromatographic techniques have been useful in class separations and analyses of petroleums. More often, these have been applied to particular analytical scale operations with fossil-derived liquids. The most common applications are for aromatic-aliphatic and molecular weight types of separations. 

Two types of soluble NADH dehydrogenase preparations are also currently studied. The high molecular weight (Type I) NADH dehydrogenase [282] is in many respects similar to Complex I, but lacks phospholipid and ubiquinone and does not catalyse rotenone-sensitive reduction of added ubiquinone-1. In addition, it has a somewhat different content of non-haem Fe and acid-labile S per FMN. 

The low molecular weight (Type II) NADH dehydrogenase is a subcomplex of the former [283,284], and may be prepared from Complex I by treatment with chao-tropic agents [285]. Type II dehydrogenase catalyses oxidation of NADH by several acceptors such as cytochrome c, ubiquinone-1 and menadione. It contains approx, four non-haem Fe and four acid-labile S/FMN, and has a molecular weight between 70 and 80000. 

By combining epoxies of different molecular weight, type and reactivity with a variety of different curing agents one has the possibility to formulate two-component systems for nearly any application in civil engineering or the building industry. Table 3.1 outlines the properties, products and application areas of epoxy systems. 

Asphaltenes clearly consist of a distribution of molecular weights, types, and polarity, which can be conveniently subdivided according to their solubility behavior in mixtiues of a good solvent (e.g., toluene or methylene chloride) and a poor or nonsolvent (e.g., heptane). The most polar or least soluble fraction of asphaltenes (as gaged by this solvent—non-solvent fractionation method) appears to form the strongest interfacial films, all other thermodynamic parameters being equal. 

The chelalion mixlure is kept for some time at elevated temperature and afterwards the mixture is separated into the aqueous phase and the organic phase. Eventually, Ihe PPE is isolated from the separated organic phase [23], In this way, a high-molecular-weight type PPE can be produced with a weight average molecular weight of 150-400 kDa. 

Natural and synthetic rubber and synthetic resins are soluble in organic solvents resulting in cements, resin solutions, or lacquers. In addition, there are many cellulose derivatives, such as nitrocellulose, ethyl cellulose, and cellulose acetate butyrate, used in preparing solvent-based adhesives. Solvent-hased adhesives are also prepared from cyclized rubber, polyamide, and polyisobutylene. Low-molecular-weight polyurethane and epoxy compounds can be used with or without solvent. On the other hand, high-molecular-weight types or prepolymers require solvent to make application possible. 

Some HALS act co-operatively with conventional flame retardants and there are high molecular weight types that are said to act as heat stabilisers. 

The identified factors include environmental parameters (ie, temperature, humidity, and velocity of the air in the chamber where the spin process is carried out), parameters related with the set-up of the process (ie, flow rate, distance between the nozzle and the counter electrode, applied voltage), and the solution properties (ie, polymer molecular weight, type of solvent used, solution concentration and conductivity, surface tension,... 

The effect of thermoplastic molecular weight and curing rate on gelation behavior has also been studied [70]. By using modified DGEBA-anhydride systems with three different molecular weight-types of PES (20 wt%) and different amounts of... 

Figure 9.16 Comparative abrasion resistance of various resins polyethylene is of ultra-high molecular weight type (Stein).

High molecular weight additives are migrating slower than low molecular weight types. For this reason the former retain their efficiency for a longer time (3, p. 53). 

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