Search results
Results from the WOW.Com Content Network
Polystyrene (PS) / ˌ p ɒ l i ˈ s t aɪ r iː n / is a synthetic polymer made from monomers of the aromatic hydrocarbon styrene. [5] Polystyrene can be solid or foamed. General-purpose polystyrene is clear, hard, and brittle. It is an inexpensive resin per unit weight. It is a poor barrier to air and water vapor and has a relatively low ...
Styrene is an organic compound with the chemical formula C 6 H 5 CH=CH 2.Its structure consists of a vinyl group as substituent on benzene.Styrene is a colorless, oily liquid, although aged samples can appear yellowish.
In IUPAC nomenclature of chemistry, a pendant group (sometimes spelled pendent) or side group is a group of atoms attached to a backbone chain of a long molecule, usually a polymer. Pendant groups are different from pendant chains, as they are neither oligomeric nor polymeric. [2] For example, the phenyl groups are the pendant groups on a ...
Chemists tend to consider the repeat unit as -[CH 2-CH 2]- since this polymer is made from the monomer ethylene (CH 2 =CH 2). More complex repeat units can occur in vinyl polymers-[CH 2-CHR] n-, if one hydrogen in the ethylene repeat unit is substituted by a larger fragment R. Polypropylene-[CH 2-CH(CH 3)] n - has the repeat unit -[CH 2-CH(CH 3)].
When this curl breaks, it leaves small chains sprouting from the main carbon backbone. Branched carbon chains cannot line up as close to each other as unbranched chains can. This causes less contact between atoms of different chains, and fewer opportunities for induced or permanent dipoles to occur. A low density results from the chains being ...
Formation of polystyrene, a polymer with an organic backbone. Common synthetic polymers have main chains composed of carbon, i.e. C-C-C-C.... Examples include polyolefins such as polyethylene ((CH 2 CH 2 ) n ) and many substituted derivative ((CH 2 CH(R)) n ) such as polystyrene (R = C 6 H 5 ), polypropylene (R = CH 3 ), and acrylates (R = CO 2 ...
In organic chemistry, a substituent is one or a group of atoms that replaces (one or more) atoms, thereby becoming a moiety in the resultant (new) molecule. [1] ( In organic chemistry and biochemistry, the terms substituent and functional group, as well as side chain and pendant group, are used almost interchangeably to describe those branches from the parent structure, [2] though certain ...
Polyisoprene of latex rubber is an example of a natural polymer, and the polystyrene of styrofoam is an example of a synthetic polymer. In biological contexts, essentially all biological macromolecules —i.e., proteins (polyamides), nucleic acids (polynucleotides), and polysaccharides —are purely polymeric, or are composed in large part of ...