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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.
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 ...
Non-linear polymers and copolymers, and polymer assemblies are named using the italicized qualifiers in Table 2. [5] The qualifier, such as branch, is used as a prefix (P) when naming a (co)polymer, or as a connective (C), e.g., comb, between two polymer names.
Flory–Stockmayer theory is a theory governing the cross-linking and gelation of step-growth polymers. [1] The Flory–Stockmayer theory represents an advancement from the Carothers equation, allowing for the identification of the gel point for polymer synthesis not at stoichiometric balance. [1]
A directorial republic is a government system with power divided among a college of several people who jointly exercise the powers of a head of state and/or a head of government. Merchant republic: In the early Renaissance, a number of small, wealthy, trade-based city-states embraced republican ideals, notably across Italy and the Baltic.
In polymer chemistry, a random coil is a conformation of polymers where the monomer subunits are oriented randomly while still being bonded to adjacent units. It is not one specific shape, but a statistical distribution of shapes for all the chains in a population of macromolecules.