Synthesis and characterisation of highly branched polyisoprene: exploiting the “Strathclyde route” in anionic polymerisation

Habibu, Shehu; Mainal, Azizah

doi:10.1039/c8ra00884a

Cited by 11 publications

(11 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Segmental mobility of polymer chains is believed to influence the glass transition of polymers. Branched polymers possess a lower glass transition temperature ( T g ) due to the presence of more free volume as a result of numerous end groups [1,49]. The differential scanning calorimetry (DSC) data presented in table 2 show that the linear samples (LPI-01 and LPI-02) exhibited higher values of T g (−15.6°C) than the branched polymers, (HBPI-01, −19.5) and (HBPI-02, −23.3°C), due to the higher chain mobility of the branched polymers over the linear polymer [60].…”

Section: Resultsmentioning

confidence: 99%

“…All the syntheses were carried out using a special reactor (‘Christmas tree’ reaction vessel), which was purified according to the similar procedure reported by Habibu et al . [1] and Hutchings et al . [31].…”

Section: Methodsmentioning

confidence: 99%

“…The solvents (99.9% benzene and HPLC grade toluene) and the monomers were purified through over CaH 2 (Aldrich) via several freeze-pump-thaw cycles on a vacuum line. All the syntheses were carried out using a special reactor ('Christmas tree' reaction vessel), which was purified according to the similar procedure reported by Habibu et al [1] and Hutchings et al [31].…”

Section: Methodsmentioning

confidence: 99%

“…The reaction was terminated with dried methanol, and the polymer was precipitated in excess methanol. 1…”

Section: Synthesismentioning

confidence: 99%

“…Strathclyde methodology is one of the ways in which the hyperbranched polymer synthesis could be achieved. It involves the copolymerization of vinyl monomers with the help of chain transfer agent that can prevent the formation of gel [1,2]. Understanding the effect of molecular architecture on the properties of polymers is of interest from both theoretical and practical perspectives [3].…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Rheological and thermal degradation properties of hyperbranched polyisoprene prepared by anionic polymerization

2019

Self Cite

View full text Add to dashboard Cite

Hyperbranched polyisoprene was prepared by anionic copolymerization under high vacuum condition. Size exclusion chromatography was used to characterize the molecular weight and branching nature of these polymers. The characterization by differential scanning calorimetry and melt rheology indicated lower Tg and complex viscosity in the branched polymers as compared with the linear polymer. Degradation kinetics of these polymers was explored using thermogravimetric analysis via non-isothermal techniques. The polymers were heated under nitrogen from ambient temperature to 600°C using heating rates from 2 to 15°C min−1. Three kinetics methods namely Friedman, Flynn–Wall–Ozawa and Kissinger–Akahira–Sunose were used to evaluate the dependence of activation energy (Ea) on conversion (α). The hyperbranched polyisoprene decomposed via multistep mechanism as manifested by the nonlinear relationship between α and Ea while the linear polymer exhibited a decline in Ea at higher conversions. The average Ea values range from 258 to 330 kJ mol−1 for the linear, and from 260 to 320 kJ mol−1 for the branched polymers. The thermal degradation of the polymers studied involved one-dimensional diffusion mechanism as determined by Coats–Redfern method. This study may help in understanding the effect of branching on the rheological and decomposition kinetics of polyisoprene.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

“…The reaction was terminated with dried methanol, and the polymer was precipitated in excess methanol. 1…”

Section: Synthesismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Rheological and thermal degradation properties of hyperbranched polyisoprene prepared by anionic polymerization

2019

Self Cite

View full text Add to dashboard Cite

show abstract

Switch from Anionic Polymerization to Coordinative Chain Transfer Polymerization: A Valuable Strategy to Make Olefin Block Copolymers

et al. 2022

View full text Add to dashboard Cite

Anionic polymerization of butadiene or/and styrene is performed with lithium initiators, functional or not. The polymer chains are subsequently transferred to magnesium. The resulting polymeryl-magnesium compounds were combined with {(Me 2 Si(C 13 H 8 ) 2 )Nd(μ-BH 4 )[(μ-BH 4 )Li(THF)]} 2 metallocene complex to act as macromolecular chain transfer agents (macroCTAs) in coordinative chain transfer polymerization (CCTP) of ethylene (E) or its copolymerization (CCTcoP) with butadiene (B). Block copolymers were produced for the first time by this switch from anionic polymerization to CCTP. Hard and soft blocks such as PB, polystyrene (PS), poly(styrene-co-butadiene) (SBR) obtained by anionic polymerization and PE or poly(ethylene-cobutadiene) (EBR) produced by CCT(co)P were combined and the corresponding structures were characterized.

show abstract

One‐Pot Structure‐Controlled Synthesis of Hyperbranched Polymers by a “Latent” Inimer Strategy Based on Diels–Alder Chemistry

et al. 2022

View full text Add to dashboard Cite

An efficient "one-pot" strategy for the structure-controlled synthesis of hyperbranched polymers (HBPs) based on a "latent" inimer (LI-Br), containing a furan-protected maleimide monomer and a haloalkane initiator, is presented. At high temperatures, the "latent" inimer is converted to a "real" inimer after releasing maleimide (MI) via a retro-Diels-Alder (r-DA) reaction and then copolymerized with methyl methacrylate by self-condensing vinyl copolymerization. Due to the dynamic characteristic of the r-DA reaction, the release of naked MI and the subsequent copolymerization can be regulated by the temperature or stereochemistry of Diels-Alder (DA) adducts. Thus, the "onepot" structure-controlled synthesis of HBPs with various degrees of branching was achieved. By further implementation of a programmable temperature change, some valuable hyperbranched topologies such as star-shaped and long-chain hyperbranched polymers can be constructed avoiding sophisticated synthetic routes.

show abstract

Synthesis and characterisation of highly branched polyisoprene: exploiting the “Strathclyde route” in anionic polymerisation

Abstract: Copolymerisation of isoprene and divinylbenzene was achieved in tolueneviaanionic chain transfer polymerization to yield highly branched polymers with good solution and rheological properties.

Cited by 11 publications

References 56 publications

Rheological and thermal degradation properties of hyperbranched polyisoprene prepared by anionic polymerization

Rheological and thermal degradation properties of hyperbranched polyisoprene prepared by anionic polymerization

Switch from Anionic Polymerization to Coordinative Chain Transfer Polymerization: A Valuable Strategy to Make Olefin Block Copolymers

One‐Pot Structure‐Controlled Synthesis of Hyperbranched Polymers by a “Latent” Inimer Strategy Based on Diels–Alder Chemistry

Contact Info

Product

Resources

About