Monomers


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Monomers

 

low-molecular-weight substances composed of molecules that interact with one another (polymerization or polycondensation) or with the molecules of other substances to form a polymer. Most of the monomers that take part in polymerization processes belong to one of two classes: (1) compounds that undergo polymerization because of the scission of multiple bonds—for example, C=C, O≡C, C=O, and C≡N (olefins, diene and acetylene hydrocarbons, aldehydes, and nitriles); and (2) compounds that polymerize because of scission of ring groups (for example, olefinic oxides, lactames, and lactones).

The monomers that take part in polycondensation reactions may be any compounds that contain no fewer than two reactive (functional) groups per molecule—for example, diamines, dicarboxylic acids, amino acids, and glycols. During polycondensation, bifunctional compounds form linear polymers, whereas compounds with more than two functions produce branched and reticular polymers.

References in periodicals archive ?
When choosing among the quite considerable number of components proposed to be used in the chemical removal of residual monomers, some aspects concerning advantages and/or disadvantages of each compound must be taken into account.
Each successive monomer is "intimately dispersed" within the matrix TABULAR DATA OMITTED polymers, Galli writes.
6-9 Mechanical properties of acrylic denture base resins, such as hardness and flexural strength, have also been known to be adversely affected by the extent of un-polymerized monomers within the matrix.
The specialty monomers vinyl neodecanoate and vinyl laurate confer special properties on Wacker's dispersible polymer powders, such as hydrophobicity.
The monomers BA and MMA were purified by reduced pressure distillation (<300 Pa and 100[degrees]C) to remove the inhibitors.
19) established criteria for the stabilization of an emulsion by trapped species for monomer droplets with an initially uniform size.
The chain length for this type of FOS is about 2 monomers to 7 monomers.
Langhals and his colleagues decided to use hydroxyethyl methacrylate--an organic monomer used to make many plastics.
This study focuses on the polymerization of polar and non-polar monomers in Pluronic[R] LLC systems and understanding how the varying degree of LLC order affects the polymerization mechanism as well as the resultant polymer morphology.
Different monomers can be added in the two reactor legs.
The analysis challenge was further complicated by a chemical composition that resulted from the use of two different monomers co-polymerized together.