Linear chain attachment polymer

Figure 1 Macromolecular architectures linear macromolecular chains (homopolymer, block-copolymer and statistical copolymer [14]), brushed-polymer (= linear chains attached to a polymer-chain brush-polymer, brush-copolymers [14]), star polymer [4], mikto-star-polymer [16], arborescent graft polymer (=repeated grafting of linear chains on a macromolecule [17,18]), dendrimer (= maximally branched, regular polymer [15])...

The amount of branching introduced into a polymer is an additional variable that must be specified for the molecule to be fully characterized. When only a slight degree of branching is present, the concentration of junction points is sufficiently low that these may be simply related to the number of chain ends. For example, two separate linear molecules have a total of four ends. If the end of one of these linear molecules attaches itself to the middle of the other to form a T, the resulting molecule has three ends. It is easy to generalize this result. If a molecule has v branches, it has v 2 chain ends if the branching is relatively low. Branched molecules are sometimes described as either combs or... 

Polyethylene glycol (PEG) consists of repeating units of ethylene glycol forming linear or branched polymers with different molecular masses. Pegylation is the process by which PEG chains are covalently attached to lEN molecules. Pegylation confers a number of properties on lEN-a molecules, such as sustained blood levels that enhance antiviral effectiveness and reduce adverse reactions, as well as a longer half-life and improved patient compliance (Kozlowski et al. 2001). 

Star shaped macromolecules are polymers, where the one end of f > 2 (f functionality of the star) linear chains is chemically attached by covalent bonds to a small central linker unit, are the simplest form of branched polymers. Modern anionic polymerization techniques allow us to synthesize star systems with a large number of nearly monodisperse arms [133, 134],... 

Poly(macromonomers) with moderately long side chains attached to every few (second) atom along the backbone are very densely branched polymers. When the degree of polymerization of the backbone is low then the poly(macromon-mers) tend to resemble star polymers [39, 40]. When the degree of polymerization is very high the poly(macromonomer) acquires a cylindrical conformation (bottlebrush), due to the stretching and linearization of the backbone [40]. 

In molecular structure of polymers (as opposed to Linear), refers to side chains attached to the main chain. Side chains may be long or short. 

The authors studied the interaction of CDs with alkyl side chains attached to the poly(acrylamide) backbone with NMR spectroscopy and found that CDs bind alkyl side chains efficiently and selectively [156]. n-Butyl side chains interacted only with a-CD. On the other hand, t-butyl side chains interacted with j6-CD and y-CD, but did not interact with a-CD. The association constant for the complex formation of fi-CD with a t-butyl side chain was larger than that for the complex formation of y-CD, indicating that the t-butyl side chain fits well in the /3-CD cavity. The association constant for the complex formation of a-CD with linear alkyl side chains increased with an increase in the carbon number of the alkyl side chain from butyl to dodecyl. Noteworthy is that CDs recognize alkyl chains on the polymer main chain more specifically than low molecular weight ones. This may be because CDs include polymer-carrying alkyl chains only from one direction. 

Han, M., Morino, S., and Ichimura, K. Factors affecting in-plane and out-of-plane photoorientation of azobenzene side chains attached to liquid crystalline polymers induced by irradiation with linearly polarized light. Macromolecules 33, 6360 (2000). 

In systems where termination is quantitative and there are no significant side reactions it is clear that the measurements will involve all polymer molecules containing reactive metal—carbon bonds, including non-propagating chains attached to aluminium after transfer. No entirely satisfactory correction procedure has been found, but the usual method is to extrapolate the linear region of the increase in metal—carbon bond concentration with time to zero time. Provided the transfer reactions are constant in rate the concentration of metal bonds [N] is given by... 

The MI method utilizes initiator-functionalized linear chains, which initiate the polymerization and crosslinking of a difunctional monomer (e.g., divinylbenzene). The active chain ends also attack the neighboring linear chains ends, and a core with crosslinked microgel is formed. In the meanwhile, certain numbers of linear chains are attached to the core. However, it is always difficult to obtain star polymers with narrow distribution of arm numbers. Quite often, many linear polymers are not attached to the core, which leads to problems in the course of the purification and for finally applications. By using multifunctional coupling agents, it is possible to get stars with uniform arm numbers. But the purification process is always unavoidable and difficult. 

Gels having dangling chains Attachment of linear polymer chains on the gel particles is another approach to increase the response rate of hydrogels (Yoshida et al. 1995). DangUng chains in a gel easily collapse or expand upon an external stimulus because one side of the dangling chain is free. 

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