Pentamethylene


Also found in: Wikipedia.

Pen`ta`meth´yl`ene


n.1.(Chem.) A hypothetical hydrocarbon, C5H10, metameric with the amylenes, and the nucleus of a large number of derivatives; - so named because regarded as composed of five methylene residues. Cf. Trimethylene, and Tetramethylene.
Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.
References in periodicals archive ?
A novel bio-based polyamide, poly(pentamethylene oxamide) (PA52), with high molecular weight has been prepared from dibutyl oxalate and renewable monomer of 1,5-pentanediamine by a two-step polymerization procedure.
have reported the synthesis and characterization of bio-based poly(pentamethylene decanediamide) (PA510) [22].
Covestro, for instance, is developing resins based on pentamethylene diisocyanate (PDI), its new biobased aliphatic isocyanate, and C[O.sub.2]-based polyether polyols.
Synthesis of Dialdehyde (A-1, A-2, A-3, A-4, A-5 and A-Ar) Dimethylene 1,2-bis(4-oxybenzaldehyde) (A-1), Tetramethylene 1,4-bis(4-oxybenzaldehyde) (A-2) , Pentamethylene 1,5-bis(4-oxybenzaldehyde) (A-3), Hexamethylene 1,6-bis(4-oxybenzaldehyde) (A-4), Octamethylene 1,6-bis(4-oxybenzaldehyde) (A-5) and Phenylene 1,4-bis[methylene(4- oxybenzaldehyde) (A-Ar) were synthesized according to the reported method.
Dinitroso pentamethylene tetramine (DNPT) and azodicarbonamide (ADCA) are two of the less toxic blowing agents, but poorer cell structure and less consistent physical properties are likely to result from their use.
Molecular weight [T.sub.g] (a) Chemicals (g [mol.sup.-1]) ([degrees]C) Polyhexamethylene carbonate diol 1015 (c) -74 (PHMC[D.sub.1015)] Polyhexamethylene carbonate diol 1990 (c) -64 (PHMC[D.sub.1990)] n = 5 and m = 7 Polyhexamethylene- 1850 (c) -63 pentamethylene carbonate diol (PHMPMCD) 4,4'-Diphenylmetane diisocyanate 250 -- (MDI) 1,4-Butanediol (BD) 90 -- [T.sub.m] (b) Chemicals ([degrees]C) State Polyhexamethylene carbonate diol 48 Solid (PHMC[D.sub.1015)] Polyhexamethylene carbonate diol 53 Solid (PHMC[D.sub.1990)] n = 5 and m = 7 Polyhexamethylene- -- Liquid pentamethylene carbonate diol (PHMPMCD) 4,4'-Diphenylmetane diisocyanate 38 Solid (MDI) 1,4-Butanediol (BD) 20 Liquid (a) Glass transition temperature.
The big breakthrough in chemical blowing agents for closed cell sponge came in 1946 with the introduction of Vulcacel BN, dinitroso pentamethylene tetramine (refs.
The miscibility of the three binary pairs (PEN/PEI, PPT/PEI, and PPT/PEI) associated with three polymers in poly(ethylene naphthalate)/poly(pentamethylene terephthalate/poly(ether imide) (PEN/PPT/PEI) blends has been discussed in the last few decades [12-23].
N,N'-dinitroso pentamethylene tetramine (H) is another cheap and widely used blowing agent in the plastic industry.
In Gilbert and Hybart's study (4) of aromatic polyester crystallization kinetics, they found poly(pentamethylene terephthalate) with five methylene units crystallized very slowly and concluded that polyesters with an odd number of methylene units are much more difficult to crystallize than polyesters with 2, 4 or 6 methylene units.
Although PTT has an odd number of methylene units in its chemical structure, it did not follow a previous study that an odd-numbered polyester is difficult to crystallize based solely on the crystallization behavior of one odd-numbered poly(pentamethylene terephthalate) and three even-numbered poly(n-methylene terephthalates).