Oligomers


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Related to Oligomers: Fibrils

Oligomers

 

members of homologous series occupying the region between monomers and polymers in terms of molecular size. The upper limit for the molecular weight of oligomers depends on their chemical nature and corresponds to the onset of high-elastic deformations, induced high elasticity, and other properties characteristic of macromolecular substances. Polar oligomers cover a wider range of molecular weights than do nonpolar oligomers (up to ∼ 1.5 × 104, as opposed to ∼ 5 × 103).

Most of the methods used in oligomer synthesis are based on macromolecule growth termination reactions in processes of polymerization and polycondensation. Oligomers are also obtained by degradation of macromolecular polymers and by stepwise synthesis, with the isolation of reaction products at each stage of the process; the latter method yields monodisperse oligomers.

Among the many reactive oligomers, the most important are polyester resins, epoxy resins, phenol-aldehyde resins, and alkyd resins, which have become widely used in the manufacture of laminated plastics, foam plastics, varnishes, adhesives, and sealing compounds. Oligoolefins are used as motor fuels and lubricants, in waterproofing treatment of paper, and in the preparation of polishing pastes (synthetic wax). Fluorine-substituted ethylene oligomers serve as high-boiling oils, heat-transfer agents, and fluids for hydraulic drives. Oligomers derived from an olefin oxide base are widely used as surface-active agents.

Oligomers play a relatively important role in nature. Examples are oxytocin (nonapeptide) and antibiotics (cyclooligopep-tides).

References in periodicals archive ?
Polysulfide Oligomer Sealants: Synthesis, Properties, and Applications
DBC develops UV curable oligomers with higher molecular weight, low visicosity, such as products DM576, 1710, 1720, 1283C for use in coating mobile phones.
In a diseased brain, the mobile amyloid beta oligomers attack the synapses of neurons, destroying memory and ultimately resulting in neuron death.
Synthesis of Poly(aryl ether ketone) Oligomers Containing Phthalonitrile (PAEK-CN)
The analysis of the plasticizing additives showed that practically all of them were oligomer electrolytes on the basis of organic aromatic compounds.
Scientists observed how this antibody fragment protected from cell death in human cell-cultures and described the molecular mechanism by which this antibody fragment removed the Abeta oligomers that cause the disease.
The company expects this approach to help decrease extracellular tau oligomers, including dimers and trimers that have recently been reported to be involved in the spread of tau pathology and to impair memory formation in animal models of Alzheimer's disease.
In unraveling oligomers' molecular structure, Guo and colleagues discovered that A[beta] has a vastly different organization in oligomers than in amyloid plaques.
Acknowledged as high quality PNA oligomer probe provider
It appears interesting to explore specific mechanisms of modifying the action of the various functional components in composite coatings based on fluorine-containing oligomers that have found widespread use in the practice of tribosystems of automotive, railway and special vehicles (Lovshenko et al.
As a result of the new agreement, Bomar Specialties will transition to Dymax Oligomers & Coatings.
com)-- Ongoing research and development by Bayer MaterialScience LLC scientists has refined polyurethane chemistry, subsequently leading to the development of a new generation of products for UV (ultra violet) curable coatings - acrylated allophanate oligomers.