Three-dimensional macromolecules

Unsaturated polyester resins prepared by condensation polymerization constitute the largest industrial use for maleic anhydride. Typically, maleic anhydride is esterified with ethylene glycol [107-21-1] and a vinyl monomer or styrene is added along with an initiator such as a peroxide to produce a three-dimensional macromolecule with rigidity, insolubiUty, and mechanical strength. 

Dendrimers and dendrons are almost perfectly monodispersed, three-dimensional macromolecules, with a well-defined tree-like globular structure and a high density of functional groups 144-461. Their size, shape, and reactivity are determined by generations [=GJ and chemical composition of the core, their degree of branching, and their surface functionalities (end groups) (Fig. 3) [44]. 

Modern nanotechnology and nanofabrication processes are advancing towards manipulation of structure and functions on the molecular scale [19-23]. Many innovations and strategic areas of research which have appeared during the last 5-10 years corroborate the famous opinion of R. Feynman there is a plenty of space on the bottom [471]. Some prominent examples include self-assembly of small molecules and their ordering at interfaces [8,220,472,473 ], three-dimensional macromolecules with a defined shape, interior and surface structure [34-38], and templating of biomolecules [39-41,474]. Most of these concepts follow a biomimetic approach, where synthetic structures mimic organisation princi-... 

Divinylbenzene (DVB) also behaves as a non-conjugated diene it can remain difunctional only upon the interruption of conjugation in the aromatic ring. This, of course, does not occur. Non-conjugated dienes are used in crosslinking copolymerizations for the preparation of insoluble three- dimensional macromolecules (especially DVB for ion-exchanger backbones) and for scientific purposes. 

These facts are discussed in detail in Secs. 2.7 and 4.5. Many other crystals, e.g., ionic crystals, semiconductors, or metals, are three-dimensional macromolecules consisting of molecules or atoms which have essentially lost their individuality. These are discus,sed in Sec. 4.8. 

Hydrophobic interactions. The base ring n cloud of electrons between stacked purine and pyrimidine bases is relatively nonpolar. The clustering of the base components of nucleotides within the double helix is a stabilizing factor in the three-dimensional macromolecule because it minimizes their interactions with water, thereby increasing entropy. 

For some time, we have been interested in designing selective chemical modification reactions for coal with a particular emphasis upon characterizing the carbon skeleton of coal (2). The strategy for the approach starts with the working hypothesis that coal can be viewed as a three-dimensional macromolecule in which aromatic and hydroaromatic clusters are cross-linked to one another by various functional groups such as methylene units and polymethylene chains. In addition, the aromatic and hydroaromatic clusters, at least in bituminous coals, are assumed to be derived from polynuclear aromatic compounds (3, 4). 

STRUCnjRE Dendrimers are three-dimensional macromolecules consisting of three major architectural components a core, branch cells, and terminal groups. These products are constructed from repeat units called branch cells [e.g.,... 

STRUCTURE Dendrimers are three-dimensional macromolecules consisting of three major architectural components a core, branch cells, and terminal groups. These products are constructed from repeat units called branch cells [e.g., —CH2—CH2—CH2—N(CH2—CH2—012)2] iri concentric generations (G) surrounding various cores according to dendritic rules and principles, where = multiplicity of core N, = multiplicity of branch cell and Z = terminal groups (i.e., -CN or —CH2-NH2). 

Dendrimers are highly ordered, hyperbranched, three-dimensional macromolecules with three distinguished architectural regions (1) the core, (2) layers of branched repeat units emanating from this core, and (3) end groups on the outer layer of repeat units [1],... 

The dendritic architectures, as highly branched and three-dimensional macromolecules that have unique chemical and physical properties, offer potential as the next great technological revolutioa This review gives a brief introduction to some of the stmctural properties and application of dendritic polymer in various fields. The focus of the paper is a survey of multi-scale modehng and simulation techniques in hyper-branched polymer and dendrimers. Results of modehng and simulation calculations on dendritic architecture are reviewed. 

Hyperbranched polymers are compact, highly branched, three-dimensional macromolecules with a high density of end-groups [84]. Their compact structure results in inherently low viscosity, as evidenced by the value of the Mark-Houwink constant a being less than 0.5. Hyperbranched aliphatic polyesters have been applied as toughners for epoxy thermosets without a significant increase in viscosity... 

The first condition to obtain an infinite three-dimensional macromolecule and consequently a network is to introduce in the polymerizing system a branching agent whose valence is at least equal to three. Its role is to allow a nonlinear growth of the chains. However, this condition is not sufficient to generate an infinite macromolecule. 

Dendrimers are highly branched, three-dimensional macromolecules with a branch point at each monomer unit they have structural features that are... 

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