《Design and Characterization of Model Linear Low-Density Polyethylenes (LLDPEs) by Multidetector Size Exclusion Chromatography》 was written by Orski, Sara V.; Kassekert, Luke A.; Farrell, Wesley S.; Kenlaw, Grace A.; Hillmyer, Marc A.; Beers, Kathryn L.. Safety of Benzylidenebis(tricyclohexylphosphine)dichlororuthenium And the article was included in Macromolecules (Washington, DC, United States) in 2020. The article conveys some information:
Separations of com. polyethylenes, which often involve mixtures and copolymers of linear, short-chain branched, and long-chain branched chains, can be very challenging to optimize as species with similar hydrodynamic sizes or solubility often coelute in various chromatog. methods. To better understand the effects of polymer structure on the dilute solution properties of polyolefins, a family of model linear low-d. polyethylenes (LLDPEs) were synthesized by ring-opening metathesis polymerization (ROMP) of sterically hindered, alkyl-substituted cyclooctenes, followed by hydrogenation. Within this series, the alkyl branch frequency was fixed while systematically varying the short-chain branch length. These model materials were analyzed by ambient- and high-temperature size exclusion chromatog. (HT-SEC) to determine their molar mass, intrinsic viscosity ([η]), and degree of short-chain branching across their resp. molar mass distributions. Short-chain branching is fixed across the molar mass distribution, based on the synthetic strategy used, and measured values agree with theor. values for longer alkyl branches, as evident by HT-SEC. Deviation from theor. values is observed for Et branched LLDPEs when calibrated using either α-olefin copolymers (poly(ethylene-stat-1-octene)) or blends of polyethylene and polypropylene standards A systematic decrease of intrinsic viscosity is observed with increasing branch length across the entire molar mass distribution. This work demonstrates the applicability of these model materials to deconvolute structure-property relationships using chromatog. separation techniques and is a step toward determining if sequence control can minimize compositional heterogeneity and generate improved standards for determining branching content in com. polyolefins. The experimental part of the paper was very detailed, including the reaction process of Benzylidenebis(tricyclohexylphosphine)dichlororuthenium(cas: 172222-30-9Safety of Benzylidenebis(tricyclohexylphosphine)dichlororuthenium)
Benzylidenebis(tricyclohexylphosphine)dichlororuthenium(cas: 172222-30-9) is the first metathesis catalyst to be widely used in organic synthesis. It is useful for acyclic diene metathesis polymerization (ADMET), Ring-Opening Metathesis Polymerization (ROMP) of strained cyclic olefins, ring opening metathesis (ROM), and so on.Safety of Benzylidenebis(tricyclohexylphosphine)dichlororuthenium
Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics