Oligomers


Also found in: Dictionary, Medical.
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 ?
DBC develops UV curable oligomers with 1,000 to 1,500 molecular weight and 1,000 to 3,000 viscosity CPS that meet the need of its global customers.
Non-invasive imaging by MRI of amyloid beta oligomers is a giant step forward towards diagnosis of this debilitating disease in its earliest form," said Dravid, the Abraham Harris Professor of Materials Science and Engineering at the McCormick School of Engineering and Applied Science.
The oligomers labeled as PAEK-CN-I and PAEK-CN-III with different molecular chain length was also obtained by varying the mole ratio of DFBN to DHBP, respectively, according to the similar procedure above.
The conducted study showed that oligomer of benzene, naphthalene and poly nuclear rank with various hydrophilic polar groups possessed plasticizing ability.
At the molecular level, researchers demonstrated two important facts: first, the treatment cleared from the cerebral cortex the Abeta peptide oligomers, the elements causing the disease; and second, this clearence is linked to the recovery of the levels of certain apolipoproteins suspected to be the natural removers of Abeta peptide aggregates.
DAEJEON, South Korea -- Panagene announced it has signed a supply agreement with Dako Denmark A/S to supply PNA oligomer key component for incorporation into Dako's diagnostic or research products.
In addition to neat oligomers, the new business unit offers diluted and partially formulated mixtures of performance oligomers with specialty monomers and other performance additives, toll and custom manufacture of formulated coatings and systems, and proprietary Dymax in-house formulated coating solutions.
Ekin discussed how allophanate-based oligomers compare in common tests with the performance of isocyanurate-based oligomers.
Abstract A series of UV-curable hyperbranched polyurethane acrylate (HBPUA) oligomers were synthesized with isophorone diisocyanatc (IPDI), hyperbranched polyester Boltorn H20 (HBP) and hydroxyethyl acrylate (HEA).
The major halobutyl elastomer extractables that can affect drug quality or compatibility are oligomers, halogenated oligomers and other residue additives/by-products present in the polymer.
Using primary murine microglia cultures, this study continued to define the mechanism by which A[beta] oligomers stimulate microglia to acquire a reactive phenotype.