Precision Polyethylene: Changes in Morphology as a Function of Alkyl Branch Size was written by Rojas, Giovanni;Inci, Bora;Wei, Yuying;Wagener, Kenneth B.. And the article was included in Journal of the American Chemical Society in 2009.Safety of 2-Cyclohexylacetonitrile This article mentions the following:
Metathesis polycondensation chem. has been employed to control the crystalline morphol. of a series of 11 precision-branched polyethylene structures, the branch being placed on each 21st carbon and ranging in size from a Me group to an adamantyl group. The crystalline unit cell is shifted from orthorhombic to triclinic, depending upon the nature of the precision branch. Further, the branch can be positioned either in the crystalline phase or in the amorphous phase of polyethylene, a morphol. change dictated by the size of the precision branch. This level of morphol. control is accomplished using step polymerization chem. to produce polyethylene rather than conventional chain polymerization techniques. Doing so requires the synthesis of a series of unique sym. diene monomers incorporating the branch in question, followed by ADMET polymerization and hydrogenation to yield the precision-branched polyethylene under study. Exhaustive structure characterization of all reaction intermediates as well as the precision polymers themselves is presented. A clear change in morphol. was observed for such polymers, where small branches (Me and ethyl) are included in the unit cell, while branches equal to or greater in mass than Pr are excluded from the crystal. When the branch is excluded from the unit cell, all such polyethylene polymers possess essentially the same melting temperature, regardless of the size of the branch, even for the adamantyl branch. In the experiment, the researchers used many compounds, for example, 2-Cyclohexylacetonitrile (cas: 4435-14-7Safety of 2-Cyclohexylacetonitrile).
2-Cyclohexylacetonitrile (cas: 4435-14-7) belongs to nitriles. Nitrile carbon shifts are in the range of 115–125 ppm whereas in isonitriles the shifts are around 155–165 ppm. Industrially, the main methods for producing nitriles are ammoxidation and hydrocyanation. Both routes are green in the sense that they do not generate stoichiometric amounts of salts.Safety of 2-Cyclohexylacetonitrile
Referemce:
Nitrile – Wikipedia,
Nitriles – Chemistry LibreTexts