Branching functionality

Comb polymers consist of a backbone and several branches [9]. Backbone and branches are usually recognized from the synthetic procedure. The branching functionality is usually limited to 3 or 4. The backbone and/or the branches can be monodisperse. In a regular comb polymer the number of branch points per backbone is constant and the branches are equidistantly spaced along the... 

A geometric growth in branching functionality and overall molecular weight is... 

The observations and questions raised by these workers helped stimulate the experiments which are presented here. In this work, size exclusion chromatography with low angle laser light scattering detection (SEC/LALLS) was used to probe the distribution of branching functionality in multiarm macromolecules of styrene/isoprene and styrene/buta-... 

Weight average branching functionality, using values in column 2. 

Figure 2c. Plots of log M and concentration (c) vs. retention voltame (v) for sample (SI-3) DVB. Values of the viscosity ratio g (v) and branching functionality f(v) are given for several retention volumes.

The weight-average branching functionality (fw) for the major MA peak (Table 11) falls between 16 and 18 for all the samples. This probably reflects the constancy of experimental preparation conditions temperature, concentration, solvent, and the ratio [DVB]/[RLi]. 

Triple-branching functionalization of complex 7 yielded nona-allyl derivative 8 which was demetallated by visible light photolysis in the presence of triphenyl-... 

From the data in Tables I and II, one observes an increase in the DVB/RLi ratio does not necessarily result in more highly branched star-shaped polydienes. In other words, an increase in the DVB/RLi ratio results in more quantitative star formation but not always increased branch functionality. 

A method for preparing branched functionalized polymers containing polyol cores, (1 ), useful in the preparation of hydrogels, is described by McManus et al. (5). 

Dendrimers are molecules with regularly placed branched repeat units. They are also known as Starburst, Cascade or Arborols. These names describe aspects of their molecular architecture. Dendrimers consist of different parts (see Fig. 1). Each dendrimer has a core or focal point. The core is the central unit of the den-drimer and can formally be regarded as the center of symmetry for the entire molecule. The core has its characteristic branching functionality, i.e. the number of chemical bond by which it is connected to the rest of the molecule (Fig. la). The focal point plays the same role as the core. Moreover,it has a chemical functional group not found elsewhere in the dendrimer. 

Stockmayer 25 subsequently developed equations relating to branched-chain polymer size distributions and gel formation, whereby branch connectors were of unspecified length and branch functionality was undefined. An equation was derived for the determination of the extent of reaction where a three-dimensional, network ( gel ) forms this relation was similar to Flory s, although it was derived using another procedure. Stockmayer likened gel formation to that of a phase transition and noted the need to consider (a) intramolecular reactions, and (b) unequal reactivity of differing functional groups. This work substantially corroborated Flory s earlier studies. 

Michalska ZM, Rogalski L, Rozga-Wijas K, Chojnowski J, Fortuniak W, Scibiorek M (2004) Synthesis and catalytic activity of the transition metal complex catalysts supported on the branched functionalized polysiloxanes grafted on sUica J Mol Catal A Chem, 208 187-194... 

A branch, functional group (Section 20.3), or multiple bond involving a carbon atom in such a chain (see next subsection) is given an address, or position on the carbon chain, which is the number of that carbon atom counting from the nearer end of the chain. 

J. = Mfy], from the universal calibration curve. We have assumed that the intrinsic viscosity of a branched polymer is equal to a branching function g expressed in terms of a parameter A equal to the (number) average number of branch points per unit molecular weight (see Equation 12-68). 

Synthesis of Star-Branched and Dendritic-Branched Functionalized Polysiloxanes... 

Branched Functionalized PolysUoxane-Silica Hybrids for Immobilization of Catalyst... 

Grafting of Branched Functionalized Polysiloxanes onto the Silica Surface... 

Within this extremely important group of monosaccharides [9,107] the typical representative bears a branched functional group at any position except the anomeric carbon, but most commonly at the C-2 and C-3, as in natural L-streptose, D-hamamelose, or L-apiose. 

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