Cyclo‐ and cyclized diene polymers. XX. Cyclopolymerization of isoprene by friedel‐crafts halides in nitrobenzene in the absence of cocatalyst

Gaylord, Norman G.; Švestka, M.

doi:10.1002/pol.1969.110070112

Cited by 16 publications

(5 citation statements)

References 7 publications

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“…In both cases, loss of double bonds to the benefit of cyclized and branched structures was also observed, depending on the polymerization conditions. In the few earlier studies related to cationic polymerization of IP, similar structures were also observed with initiating systems such as BF 3 ,42, 43 SnCl 4 ,42, 43 AlCl 3 ,42, 43 AlEtCl 2 44 and SnCl 4 /CCl 3 COOH 45. Recent systems making use of TiCl 4 /CCl 3 COOH or CF 3 COOH46–49 and 1‐(4‐methoxyphenyl)ethanol/B(C 6 F 5 ) 3 50 confirmed such complex chemistry.…”

Section: Introductionsupporting

confidence: 65%

Bio‐inspired cationic polymerization of isoprene and analogues: state‐of‐the‐art

Ouardad

Bakleh

Kostjuk

et al. 2011

Polymer International

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Natural rubber (NR), which is polyisoprene about 100% 1,4-cis of high molar mass, >10 6 g mol −1 , is mainly produced in southeast Asia and represents around 40%-45% of total worldwide elastomer consumption. Whereas more than 2500 plant species are able to produce polyisoprenoids, the only established commercial source of NR is Hevea braziliensis. NR presents high performance properties that are so far not matched by synthetic rubbers. As a consequence, NR is irreplaceable in many applications (aircraft tires, surgery gloves etc.). Nature and synthetic polymer chemists start from different substrates to synthesize polyisoprenes, i.e. isopentenyl pyrophosphate (IPP), which is a universal building brick utilized by plants and animals, and isoprene monomer, respectively. Nevertheless, we proposed that the elementary processes involved in the biosynthesis of NR are very similar to those of cationic polymerization. In the course of a study on bio-inspired cationic polymerization of isoprene and IPP analogues, it appeared that cationic polymerization of isoprene proceeds readily and leads mainly to its 1,4-trans addition; such a process nevertheless remains difficult to control due to the occurrence of many side reactions (transfer, protic initiation, branching, cyclization). The present paper describes our understanding of the cationic polymerization of isoprene and its analogues catalyzed by different Lewis acids, in solution and aqueous dispersions.

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Section: Introductionsupporting

confidence: 65%

Bio‐inspired cationic polymerization of isoprene and analogues: state‐of‐the‐art

Ouardad

Bakleh

Kostjuk

et al. 2011

Polymer International

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“…There is a general tendency toward 1,4-polymerization with trans 1,4 favored over cis 1,4. Cyclization occurs during propagation with the extent of unsaturation in the product varying from about 80% to almost zero depending on initiator, monomer, and reaction conditions [Delfour et al, 2003;Gaylord and Svestka, 1969;Gaylord et al, 1968;Hasegawa and Asami, 1978;Hasegawa et al, 1977].…”

Section: -10c Cationic Polymerizationmentioning

confidence: 99%

Stereochemistry of Polymerization

Odian

2004

Principles of Polymerization

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Constitutional (formerly: structural) isomerism is encountered when polymers have the same overall chemical composition (i.e., same molecular formula) but differ in connectivitythe order in which the atoms are connected to each other. Polyacetaldehyde, poly(ethylene oxide), and poly(vinyl alcohol) are constitutional isomers. The first two polymers are CH CH 3 O C H 2 CH OH CH 2 CH 2 O n n Polyacetaldehyde Poly(ethylene oxide) Poly(vinyl alcohol) n obtained from isomeric monomers, acetaldehyde and ethylene oxide. The third is obtained by hydrolysis of poly(vinyl acetate) since vinyl alcohol does not exist (it is the enol form of acetaldehyde). Poly(methyl methacrylate) and poly(ethyl acrylate) are isomeric polymers CH 2 C CH 3 CO 2 CH 3 CH 2 CH CO 2 C 2 H 5 n n Poly (methyl methacrylate) Poly (ethyl acrylate) formed from isomeric monomers. Poly(E-caprolactam) and poly(hexamethylene adipamide) are isomeric even though the monomers are not isomeric. Similarly, the 1 : 1 copolymer of Principles of Polymerization, Fourth Edition.

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“…Loss of unsaturation has been frequently observed and it was mainly attributed to cyclization (133). For example, trans-1,4 enchainment of butadiene or isoprene can readily undergo carbocationic cyclization (134,135), as shown in Figure 8. Not surprisingly, no reports were found on the controlled carbocationic polymerization of dienes.…”

Section: Kinetics and Mechanisms Of Carbocationic Polymerizationsmentioning

confidence: 99%

Carbocationic Polymerization

Puskás

Kaszás

2003

Encyclopedia of Polymer Science and Technology

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This article summarizes fundamental and general aspects of carbocationic polymerizations, with a historical overview and up‐to‐date references. Following general considerations, the basic elements of carbocationic polymerization, such as monomers, initiating systems, solvents, and temperature, are discussed. Special attention is given to carbocation stability and monomer nucleophilicity, and dynamic interactions. The section on the kinetics of carbocationic polymerization presents current understanding of the elementary reactions—initiation, propagation, termination, and transfer reactions, and copolymerization. Controlled (living) carbocationic polymerization is discussed in a separate section. Finally, industrial carbocationic polymerizations are reviewed.

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Cyclo‐ and cyclized diene polymers. XX. Cyclopolymerization of isoprene by friedel‐crafts halides in nitrobenzene in the absence of cocatalyst

Cited by 16 publications

References 7 publications

Bio‐inspired cationic polymerization of isoprene and analogues: state‐of‐the‐art

Bio‐inspired cationic polymerization of isoprene and analogues: state‐of‐the‐art

Stereochemistry of Polymerization

Carbocationic Polymerization

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