Telechelic diene prepolymers. II. Carboxyl‐terminated polydienes

Reed, Samuel F.

doi:10.1002/pol.1971.150090804

Cited by 35 publications

(11 citation statements)

References 7 publications

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“…In 1971, Reed reported the synthesis of carboxy-telechelic poly(butadiene) and poly(isoprene) using 4,4′-azobis(4-cyanovaleric acid) as radical initiator; however, this method had poor control over the functionality and materials with a range of functionalities ( F = 1–3.4) were obtained. In 2000, Morita et al reported the synthesis of carboxy-telechelic poly(butadiene) ( F ∼ 2) from ROMP of cis , cis -1,5-cyclooctadiene using cis -1,4-bis(2- tert -butoxycarbonyl)-2-butene as a CTA, followed by acidic deprotection which yielded the carboxy-telechelic polymer .…”

Section: Introductionmentioning

confidence: 99%

Carboxy-Telechelic Polyolefins in Cross-Linked Elastomers

Martínez

Hillmyer

2014

Macromolecules

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We demonstrate that ring-opening metathesis copolymerization of 3-hexyl-cis-cyclooctene and cis-cyclooctene in the presence of maleic acid as a chain transfer agent leads to precise control over the molar mass, branching and crystallinity of the resulting carboxy-telechelic polyalkenamers. Subsequent hydrogenation using a silica-supported platinum catalyst had a negligible effect on the carboxy functionality and led to telechelic polyolefins with high thermal resistance, low glass transition temperatures (<−57 °C), little to no crystallinity, and viscosities similar to those of liquid silicon rubber prior to cross-linking. These properties are ideal for easily processable reactive polyolefin prepolymers that can be readily cured to form elastomers. We demonstrate that a fast and controlled curing process can be achieved in the presence of polyfunctional aziridines. The properties of the thermoset elastomer products were evaluated by tensile, differential scanning calorimetry, and dynamic mechanical analyses.

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Section: Introductionmentioning

confidence: 99%

Carboxy-Telechelic Polyolefins in Cross-Linked Elastomers

Martínez

Hillmyer

2014

Macromolecules

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“…very important. Although N,N-dimethylformamide (DMF), acetonitrile and Dox have been proposed [53]; however, Dox was used as the solvent in the present work.…”

Section: Resultsmentioning

confidence: 99%

“…1-4. In the conventional FRP of Bu (reaction B1), conversion reached 54.8% after 2900 min while conversion was only 21.4% after 3300 min in the iodidemediated radical homopolymerization of Bu (reaction B2) where monomer concentration was higher than but initiator concentration was lower (approximately halved) than those in the reaction B1 (Table 1 Due to a limited solubility and low efficiency of ACVA in the pure Bu liquid, solvent should present in the reaction medium to perform a successful reaction [53,54]. For Bu polymerization initiated with ACVA in the bulk state, reaction did not show any conversion after 3930 min in the presence of molecular I 2 (Fig.…”

Section: Conversion Versus Time Datamentioning

confidence: 99%

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Radical polymerization of butadiene mediated by molecular iodine: a kinetic study of solution homopolymerization

Abdollahi

Hajiataloo

2021

J Polym Res

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Homopolymerization of butadiene (Bu) in 1,4-dioxane (Dox) was performed at 70 °C using molecular iodine (I 2 ) in the presence of 4,4'-azobis(4-cyanovaleric acid) (ACVA), resulting in α-carboxyl ω-iodine heterotelechelic polybutadiene. Effect of Dox concentration, molar ratio of ACVA to I 2 and initiator type on the Bu conversion was studied. Inhibition of the reaction by molecular I 2 was observed until complete consumption of the I 2 (induction period). Then, polymerization initiated by carboxyl-functionalized alkyl iodides in situ generated during induction period. ACVA decomposition rate constant (k d ), induction time t ind and k 2 p ∕k t ratio were calculated using Bu conversion as a function of time data. A good agreement between the theoretical and experimental changes in the conversion versus time was observed, indicating accuracy of the kinetic parameters estimated in this work. Experimental t ind was always less that theoretical one. It was attributed to reaction between Bu and I 2 , resulting in butadiene diiodide (I-Bu-I) compound. Formation of I-Bu-I species was further confirmed by 1 H-NMR analysis of end functional groups (i.e. alkyl iodide and allyl iodide) of polybutadiene chains. Based on the 1 H-NMR analysis, [I-Bu-I]/[I 2 ] 0 ratio was obtained for reaction B4 to be 0.235. It was found that among 1,2 and 1,4 additions, 1,2 addition of I 2 to Bu is the dominant reaction. Exchange constant between the growing and dormant species (C ex ) was estimated using GPC and conversion data to be in the range of 3.20-3.94. Then, M n and D evolution with conversion was investigated theoretically. Fraction of − carboxyl, − iodide heterotelechelic PBu chains f HOOC−PBu−I relative to all chains was estimated from 1 H-NMR data to be 87% for reaction B4.

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“…Over the past several years there has been an increasing interest in the synthesis of polymers with low glass transition temperatures and reactive functional groups at each end of a given polymeric chain. They have found use as agents capable of modifying the thermal and mechanical properties of condensation polymers, in the formation of polymeric networks, and as components in the synthesis of block copolymers. − Telechelic hydroxyl, − amino, − and carboxyl , poly(butadiene)s 1 (PBD)s are excellent examples of such polymers that have been employed in the above applications. While these telechelic polymers can be synthesized through the radical or anionic polymerization of 1,3-butadiene using the appropriate initiating or terminating agents, there are several drawbacks.…”

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confidence: 99%