Olefin metathesis in multiblock copolymer synthesis

• Maria L. Gringolts,
• Yulia I. Denisova,
• Eugene Sh. Finkelshtein and
• Yaroslav V. Kudryavtsev

Beilstein J. Org. Chem. 2019, 15, 218–235, doi:10.3762/bjoc.15.21

• 1,4-polybutadiene or natural polyisoprene and olefin-containing polyester or polyurethane prepared via step-growth polymerization (Figure 4B and C) [83][84][85]. The multiblock copolymers from polybutadiene and olefin-containing polyurethane demonstrated improved mechanical properties [85]. Head-to

• -tail regioregular and E-stereoregular multiblock copolymers and heterotelechelic polymers were successfully synthesized by the cross metathesis between different ROMP-derived poly(3-substituted cyclooctenes), (Figure 4D) [86]. The MCM between immiscible commercial polybutadiene and polyisoprene led to

• sufficient to carry out the process effectively [86][87]. In the PBD–polyisoprene (PI) cross metathesis, Gr1 can be replaced by Gr–H1 but longer reaction times are needed [87]. A control over the reaction kinetics can be sometimes complicated because the overall composition of a polymer mixture does not

Superstructures with cyclodextrins: Chemistry and applications IV

• Gerhard Wenz

Beilstein J. Org. Chem. 2017, 13, 2157–2159, doi:10.3762/bjoc.13.215

• -dienes and bulky stoppers in the presence of CDs (so-called rotaxa-polymerization) was further applied for the syntheses of water-soluble polyisoprene polyrotaxanes [25]. Furthermore, ABA-type block-copolyrotaxanes could be synthesized using this polymerization technique controlled by RAFT chain transfer

One-pot synthesis of block-copolyrotaxanes through controlled rotaxa-polymerization

• Jessica Hilschmann,
• Gerhard Wenz and
• Gergely Kali

Beilstein J. Org. Chem. 2017, 13, 1310–1315, doi:10.3762/bjoc.13.127

• act as stoppers for the cyclodextrin rings threaded onto the inner polyisoprene block. Statistical copolyrotaxanes were synthesized by RAFT polymerization as well. RAFT polymerization conditions allow control of the composition as well as the sequence of the constituents of the polymer backbone which

• further effects the CD content and the aqueous solubility of the polyrotaxane. Keywords: block copolymer; cyclodextrin; polyisoprene; polyrotaxane; RAFT polymerization; Introduction Polymer necklaces, i.e., polyrotaxanes and pseudopolyrotaxanes, are supramolecular assemblies comprising polymeric axes

• already started from a PEG α-CD pseudopolyrotaxane, but unthreading of α-CD was found to be a severe problem during polymerization, which could only be overcome by elaborate attachment of “molecular hooks” to both chain ends [30]. Furthermore, polyisoprene is advantageous for biomedical applications

Organotellurium-mediated living radical polymerization under photoirradiation by a low-intensity light-emitting diode

• Yasuyuki Nakamura and
• Shigeru Yamago

Beilstein J. Org. Chem. 2013, 9, 1607–1612, doi:10.3762/bjoc.9.183

• filter. However, control of the light intensity was difficult under such conditions. For example, when light of a relatively high intensity was used to prepare a polyisoprene using TERP, a radical coupling reaction occurred because of the efficient formation of the polymer-end radical [38]. In addition

Miniemulsion polymerization as a versatile tool for the synthesis of functionalized polymers

• Daniel Crespy and
• Katharina Landfester

Beilstein J. Org. Chem. 2010, 6, 1132–1148, doi:10.3762/bjoc.6.130

• , and butyl methacrylate was also copolymerized with 2-aminoethyl methacrylate by the same authors [42]. Cell–particle investigations were performed with polyisoprene and copolymers of styrene and isoprene fluorescent particles. Their uptake was found to be faster in comparison to polystyrene particles

• from polyisoprene and that these can be further crosslinked. Latexes with double functionality were also prepared by the free-radical polymerization of divinylbenzene in miniemulsion [46][47]. The remaining vinyl group after polymerization could be, for instance, reacted with thiol-functionalized PEG

Functionalized polymers: synthesis and properties

• Helmut Ritter

Beilstein J. Org. Chem. 2010, 6, No. 55, doi:10.3762/bjoc.6.55

• , naturally occurring polymers as cellulose or polyisoprene were simply modified, for example by esterification or cross-linking to obtain the desired properties. Hermann Staudinger, for instance, chemically modified starch to prove the existence of high molecular weight substances. Nowadays, the development