Ring-opening metathesis polymerization of 8-membered cyclic olefins

Abstract

Ring-opening metathesis polymerization (ROMP) involving 8-membered cyclic olefins, such as the parent molecules cis-cyclooctene (COE) and cis,cis-1,5-cyclooctadiene (COD), leads to various polyalkenamers that have broad potential in a variety of fields. The use of different catalysts and diverse functionalized monomers allows for control over molar mass and architecture in the resultant polymers. We review the ROMP of unsubstituted and substituted COE and COD to tune the properties of the resultant homopolymers and copolymers. Starting with a survey of homopolymers, we report the strengths and limitations of the ROMP of functionalized 8-membered ring olefins. Then we show how these monomers are used to control crystallinity, hydrophobicity and morphology, in various types of copolymers.

Effects of Grafting Density on Block Polymer Self-Assembly: From Linear to Bottlebrush

“…Ring-opening metathesis polymerization (ROMP) is a powerful strategy to 6 synthesize well-defined bottlebrush polymers in a controlled and living manner. [49][50][51][52] We targeted poly(D,L-lactide)-b-polystyrene (PLA-b-PS) graft diblock polymers to permit comparisons with brush PLA-b-PS systems previously investigated in the context of self-assembly. [21][22][23][24][25] All polymerizations were carried out in CH2Cl2 at room temperature under an inert atmosphere.…”

Olefin metathesis meets rubber chemistry and technology

“…It is also worth mentioning that ROMP of 1,5-cyclooctadiene also yields BR (see also Fig. 5), as shown in many different works [16,21,30,36], and BR with 99 % cis double bonds has been synthesized with this approach [58]. However, alternative synthetic routes via butadiene are more economical, so that both ROMP routes-via cyclobutene and 1,5-cyclooctadiene-are not applied for the industrial production of BR.…”

“…However, many other strong catalyst systems were implemented in the last decades for the synthesis of polyoctenamer [17,21,[31][32][33][34][35]. The cis/trans ratio as well as the formation of cyclic polymers strongly depends on the initiator system; polymers with high cis content exhibit a lower melting temperature as well as a lower crystallinity [36]. Consequently, Vestenamer 6213 Ò with a content of 56 % trans double bonds shows a reduced melting and crystallization temperature [37].…”

“…In this field, olefin metathesis, especially ROMP, and also ADMET, has been impressively shown to be powerful tools to synthesize such functional (co)polymers. Regarding ROMP, a large variety of substituted monomers are accessible, such as substituted cyclobutenes [74,75], cyclooctenes [36], and norbornenes [3]. However, many of these approaches are devoted to special applications and not related to rubber chemistry.…”

Recent developments in the synthesis of sequence controlled polymers

“…The regio-and stereo-selectivity were discussed by Hillmyer and coworkers [63] in great detail in a review. They found that substitution at 3-position was critical to obtain high regio-and stereo-selectivity in the resultant polymers.…”