Molecular Weight Nuclear magnetic resonance,

The water slurry of SP-300 was acidified to pH 2 with 10% HCL to obtain two forms of precipitates one was lumpy and the other was powder-like. After separation from the solution, each form of precipitate was dried. The former was designated as fraction I and the latter, fraction J. The solid product from SP-300 was acidified, separated from the solution and dried. Then the product was extracted with pyridine at room temperature with a solvent/sample ratio of 10. The soluble portion was called fraction K. Thus SP-300 was divided into four fractions fractions I, J, K, and Pyridine-Insoluble. Likewise, SP-320 was divided into four fractions fractions I Jf, K, and Pyridine-Insoluble. Figure 1 summarizes the procedures used in the preparation of all CDL products. Elemental compositions, molecular weight, nuclear magnetic resonance and infrared spectra were obtained for each major fraction. Details of the preparation of specific fractions of HVL-P and solubilization products and analyses can be found elsewhere (13,14). 

Most hydrocarbon resins are composed of a mixture of monomers and are rather difficult to hiUy characterize on a molecular level. The characteristics of resins are typically defined by physical properties such as softening point, color, molecular weight, melt viscosity, and solubiHty parameter. These properties predict performance characteristics and are essential in designing resins for specific appHcations. Actual characterization techniques used to define the broad molecular properties of hydrocarbon resins are Fourier transform infrared spectroscopy (ftir), nuclear magnetic resonance spectroscopy (nmr), and differential scanning calorimetry (dsc). 

An unusual method for the preparation of syndiotactic polybutadiene was reported by The Goodyear Tire Rubber Co. (43) a preformed cobalt-type catalyst prepared under anhydrous conditions was found to polymerize 1,3-butadiene in an emulsion-type recipe to give syndiotactic polybutadienes of various melting points (120—190°C). These polymers were characterized by infrared spectroscopy and nuclear magnetic resonance (44—46). Both the Ube Industries catalyst mentioned previously and the Goodyear catalyst were further modified to control the molecular weight and melting point of syndio-polybutadiene by the addition of various modifiers such as alcohols, nitriles, aldehydes, ketones, ethers, and cyano compounds. 

N-Morpholino)propanesulfonic acid Relative molecular weight (dimensionless number) Nicotine amide adenine dinucleotide, oxidized form Nicotine amide adenine dinucleotide, reduced form Nuclear magnetic resonance... 

A field of application of MD that is beginning to bear fruit is the refinement of data from nuclear magnetic resonance (NMR) and from diffraction experiments. High-resolution NMR at frequencies around 500 MHz is able to resolve individual proton resonances of biological macromolecules in solution with molecular weights exceeding 10,000... 

Gadolinium-dendrimer conjugates have been used as blood pool contrast agents in vivo for nuclear magnetic resonance imaging (MRI) of tumors [65]. The efficacy of the conjugates in such applications is dependent on their biodistribution properties, and these properties vary as a function of dendrimer molecular weight and chemical composition [50]. Dendrimer architecture and synthesis... 

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