Acyclic diene metathesis modeling

Also, a series of well-defined polyolefins, including perfectly branched polyethylene and ethylene/a-olefin copolymers, have been synthesised via acyclic diene metathesis polycondensation [scheme (28)] [47] these well-defined polyolefins have been designed to model the crystallisation of polyethylene and olefin copolymers. 

Schwendeman JE, Wagener KB (2002) Polym Prepr 43 280 Brzezinska KR, Wagener KB, Burns GT (1999) J Polym Sci Pol Chem 37 849 Schwendeman JE (2002) Amorphous telechelic hydrocarbon diols and ethylene-based model copolymers via acyclic diene metathesis. PhD Dissertation, University of Florida, Gainesville, FL... 

The next approach for obtaining higher molecular weight polymers was to explore acyclic diene metathesis (ADMET) polymerizations.The aim was to achieve higher molecular weight flame-resistant polymers. We modeled the reaction using aliphatic diene monomers such as 1,5-hexadiene and 1,9-deca-diene under test conditions to optimize conditions before making BPC-derived products. At this point, we decided to functionalize the BPC with an olefin. 

In addition to their catalytic evaluation using classical model compounds, ruthenium indenylidene catalysts have been employed in RCM for the synthesis of natural products [15, 83-85], as well as in CM [49, 87, 88], acyclic diene metathesis (ADMET) [89], ROMP [21f, 65], and dienyne metathesis [90]. 

A different approach of modeling ethylene-based copolymers is presented using acyclic diene metathesis (ADMEl) polymerization. Monomer s)mtiiesis dictates final polymer structure due to step-growth chemistry yielding only to olefin metathesis. While copolymerization of ethylene with a-olefins produces random distribution of alkyl branches along the PE backbone, polymerization of one kind of symmetric macromonomer produces PE with a perfectly known primary structure, as seen in Figure 1. 

Acyclic diene metathesis polymerization (ADMET) polymerization leads to polymers with precisely defined microstruetures and, hence, to excellent models to study the crystallization behavior of highly branehed ethylene copolymers. With ADMET, variation in the monomer structure gives access to a broad range of precisely defined polymers, allowing direet correlation of structure-property relationships. This clean polycondensation ehemistry is used here to produce a branched architecture characterized by the preeise branch placement every n fixed mefliylene units according to the following structural repeating unit ... 

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