Oligomer properties

Oligomer properties drastically depend on their ethoxylation degree. For instance, oligomers may be compared from the value of their partition coefficient in a typical water-oil system, which is the ratio of the oligomer concentrations in water and oil at ambient temperature and in absence of micelle (fC = Cw/Co). It is found that for oligomers with EON = 3 and EON = 7 the partition coefficients between water and heptane at 25 °C are respectively 0.003 and 0.17 [11]. 

Features Fast cure speed low initiation energy high gloss good flexibility vs. hardness high solvency with vinyl ether oligomers Properties Gardner < 1 clear low-vise, liq. low odor sp.gr. 1.103 vise. 85 cps (22 C) flash pt. (Pensky) > 300 F ref. index 1.509 surf. tens. 

Trade Names Containing lgepal OD410 Phenol alcohol. See Phenol Phenol, o-(t-butyl)-. See 2-t-Butylphenol Phenol calcium saH. See Calcium phenoxide Phenolcarbind. See Benzyl alcohol Phenol, dimethyl-. See Xylenol Phenol, 3,4-dimethyl-. See 3,4-Xylenol Phenol, dinonyh. See Dinonyl phenol Phenol-fonnaldehyde sulfonate Synonyms Resole sulfonate Classification Oligomer Properties Water-sol. 

These special properties are primarily the fact that oligomers are much more inclined to form more or less anisotropic aggregates than polymers with similar chemical structures. It is these anisotropic aggregates that allow us to declare macroscopic oligomer properties to be unique [11, 13, 15-20]. 

At the beginning of a project, the model system must be determined. Oligomers can be used to model properties that are a function of local regions of the chain only. Simulations of a single polymer strand can be used to determine the tendency to fold in various manners and to hnd mean end-to-end distances and other properties generally considered the properties of a single mol-... 

Ah initio calculations of polymer properties are either simulations of oligomers or band-structure calculations. Properties often computed with ah initio methods are conformational energies, polarizability, hyperpolarizability, optical properties, dielectric properties, and charge distributions. Ah initio calculations are also used as a spot check to verify the accuracy of molecular mechanics methods for the polymer of interest. Such calculations are used to parameterize molecular mechanics force fields when existing methods are insulficient, which does not happen too often. 

Polythiophene can be synthesized by electrochemical polymerization or chemical oxidation of the monomer. A large number of substituted polythiophenes have been prepared, with the properties of the polymer depending on the nature of the substituent group. Oligomers of polythiophene such as (a-sexithienyl thiophene) can be prepared by oxidative linking of smaller thiophene units (33). These oligomers can be sublimed in vacuum to create polymer thin films for use in organic-based transistors. 

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