Chain oligomer

Radicals generated from water-soluble initiator might not enter a micelle (14) because of differences in surface-charge density. It is postulated that radical entry is preceded by some polymerization of the monomer in the aqueous phase. The very short oligomer chains are less soluble in the aqueous phase and readily enter the micelles. Other theories exist to explain how water-soluble radicals enter micelles (15). The micelles are presumed to be the principal locus of particle nucleation (16) because of the large surface area of micelles relative to the monomer droplets. 

Serelis and Solomon108 found that primary radical termination of oligo(MAN) radicals (16) with 15 also gives predominantly combination. The ratio kllt/klc was found to have little, if any, dependence on the oligomer chain length (n<4). As with PMMA, disproportionation involves preferential abstraction of a methyl... 

In self-nucleation, the extended oligomer chain collapses upon itself to nucleate a particle. 

First, the water soluble initiator decomposes to form free radicals in the aqueous phase. These free radicals then add to comonomers dissolved in the aqueous phase to start a free radical oligomer chain. If the monomers are present to a greater concentration than the saturation concentration, they form a separate comonomer droplet phase. This phase then acts as a reservoir to feed the polymerization which occurs in the polymer (latex) particles. Monomers diffuse into the aqueous phase, diffuse into the polymer particles, and polymerize. 

The length of the oligomer chain plays a role in the stereospecificity, the presence of a few units in the initiating chain leads to an increase in diastereoselectivity, as was also found for growing propene oligomers. Thus, the hindrance between chain and metal catalyst contributes to the orientation of the phenyl substituent of the incoming styrene molecule. 

Energy involved in adding monomer units to an oligomer chain... 

Formation of Cyclic Oligomers. Chain transfer reactions occur by intermolecular attack of oxygen from another polyether chain on the a-methylene carbons of the oxonium ion. In an intramolecular attack a distant oxygen of the growing polymer chain itself attacks the a-methylene position of its oxonium center. 

Irregular polymers in which polymer or oligomer chains are attached to the main chain (as in graft copolymers) are named as follows. The attached polymer or oligomer chains are considered to be substituents to the main chain and named in the same way as regular polymers [1] or irregular polymers (cf Rules 1 and 2) but without the suffix -yl. The atom in the attached chains nearest to the point of attachment to the main chain is given the locant 1. 

It was reported that the oligomer chain was essentially inactive at the later stage of polymerization, owing to the pseudo-... 

This is the direct evidence for the existence of the ketone unit in the polymer and oligomer chains. 

In the second stage a crosslinking agent, e.g., l,4,4a,5,8,8a-hexa-hydro-l,4,5,8-dimethanonaphthalene is added, which forms the crosslinked matrix. A polymer is formed where the linear oligomer chains are fixed at the crosslinked matrix as pendent groups. 

The first important question to be answered concernes the lower limit of molecular weight down to which the concepts obtained for long Gaussian or latticelike chains were applicable. It is clear that a Gaussian chain does not adequately describe the conformational properties of short oligomer chains. Other models e.g. a model of the wormlike chain may be more suitable. The introduction of this model may lead to considerable mathematical complications and the determination of Kd may become difficult. 

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