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In polymer science, star-shaped polymers are the simplest class of branched polymers with a general structure consisting of several (at least three) linear chains connected to a central core. [1] The core, or the center, of the polymer can be an atom , molecule , or macromolecule ; the chains, or "arms", consist of variable-length organic chains.
A star-shaped polymer molecule is a branched polymer molecule in which a single branch point gives rise to multiple linear chains or arms. If the arms are identical the star polymer molecule is said to be regular. If adjacent arms are composed of different repeating subunits, the star polymer molecule is said to be variegated.
Branch point in a polymer. Polymer architecture in polymer science relates to the way branching leads to a deviation from a strictly linear polymer chain. [1] Branching may occur randomly or reactions may be designed so that specific architectures are targeted. [1] It is an important microstructural feature.
Star fullerene polymers can be prepared by two major approaches. Reported star fullerene polymers were prepared by anionic copolymerization with polystyrene to form C 60 (CH 2 CH(C 6 H 5 )) x ) n , where n stands for the number of polystyrene star “arms” from 2 to 6.
Crystal structure of a first-generation polyphenylene dendrimer reported by Müllen et al [5] A first-generation "cyanostar" dendrimer and its STM image [6]. The first dendrimers were made by divergent synthesis approaches by Fritz Vögtle in 1978, [7] R.G. Denkewalter at Allied Corporation in 1981, [8] [9] Donald Tomalia at Dow Chemical in 1983 [10] and in 1985, [11] [12] and by George R ...
With the new, expanded 12-team playoff this year, a conference championship has never been more important. Five automatic bids are doled out to the five highest-ranking conference champs, meaning ...
Branched polymers with the same molecular weight usually demonstrate different physical properties due to that branching could generally decrease the van der Waals interactions between each of the polymer chain. Several well-known branched polymers have been synthesized, such as star-shape polymer, comb polymer and dendrimer.
The first ever close-up picture of a star outside of our galaxy has shown that it is wrapped in a strange structure. The image shows a star named WOH G64 that is surrounded by gas and dust.