Anionic Polymerization of Chiral Isocyanate and Influence of the Initiator on Changes in the Optical Activity

Shin, Yeong‐Deuk; Ahn, Jun‐Hwan; Lee, Jae‐Suk

doi:10.1002/1521-3927(20010901)22:13<1041::aid-marc1041>3.0.co;2-j

Cited by 26 publications

(25 citation statements)

References 8 publications

(15 reference statements)

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“…MWD of PTEtSPI with nearly quantitative yield was narrowed down (1.09–1.13) as measured by SEC–LS. Although in the case of polymerization of HIC, with 10 times of NaBPh 4 to the initiator, 20 min of time were required to complete the polymerization in which stability of the living, polymeric chain was observed only up to 30 min 16, 17. The reactivity of TEtSPI was comparatively lower than that of HIC because of the presence of the bulky triethylsilyl group.…”

Section: Resultsmentioning

confidence: 99%

“…Initial experiments involved the polymerization of TEtSPI with Na‐Naph as an initiator at −98 °C with different time intervals based on preliminary experiments and previous studies 13–17. Yields of the polymer increased quantitatively by the reaction time of 20 min (Table 1).…”

Section: Resultsmentioning

confidence: 99%

“…When the interchange between the different initiating species cannot occur fast enough relative to propagation, there is a disparity between the propagation and initiation rate. The addition of NaBPh 4 as a common ion salt to suppress the presence of free ions was useful in the polymerization of HIC 16, 17…”

Section: Resultsmentioning

confidence: 99%

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Generation of highly stable amidate anion in anionic polymerization of 3-(triethylsilyl)propyl isocyanate

Ahn

Lee

Shin

et al. 2004

J. Polym. Sci. A Polym. Chem.

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To study living anionic polymerization, 3‐(triethylsilyl)propyl isocyanate (TEtSPI) monomer was synthesized by hydrosilylation of allylamine with triethylsilane and treatment of the resulting amine with triphosgene. The polymerization of TEtSPI was performed with sodium naphthalenide (Na‐Naph) as an initiator and in the absence and presence of sodium tetraphenylborate (NaBPh4) as an additive in tetrahydrofuran (THF) at −78 and at −98 °C. A highly stabilized amidate anion for living polymerization of isocyanates was generated for the first time with the combined effect of the bulky substituent and the shielding action of the additive NaBPh4, extending the living character at least up to 120 min at −98 °C. Even the anion could exist at −78 °C for 10 min. A block copolymer, poly(n‐hexyl isocyanate)‐b‐poly[(3‐triethylsilyl)propyl isocyanate]‐b‐poly(n‐hexyl isocyanate), was synthesized with quantitative yields and controlled molecular weights via living anionic polymerization in THF at −78 °C for TEtSPI and −98 °C for n‐hexyl isocyanate, respectively, with Na‐Naph with three times of NaBPh4 as a common ion salt. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 933–940, 2004

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Generation of highly stable amidate anion in anionic polymerization of 3-(triethylsilyl)propyl isocyanate

Ahn

Lee

Shin

et al. 2004

J. Polym. Sci. A Polym. Chem.

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“…The living polymerization of isocyanate is difficult because trimer formation can cause depolymerization. Numerous strategies to avoid depolymerization during the polymerization of isocyanate have been investigated 4–13…”

Section: Introductionmentioning

confidence: 99%

“…We have reported the successful synthesis of polyisocyanates via living anionic polymerization with sodium naphthalenide (Na‐Naph) as an initiator with several additives, such as 15‐crown‐59 and sodium tetraphenylborate (Na‐Ph 4 B) 10, 11. These additives made metal complex at the growing chain ends and effectively suppressed formation of trimers by steric hindrance effects.…”

Section: Introductionmentioning

confidence: 99%

Enolate anionic initiator, sodium deoxybenzoin, for leading living natures by formation of aggregators at the growth chain ends

Min

Yoo

Shah

et al. 2013

J. Polym. Sci. A Polym. Chem.

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The living anionic polymerization of n-hexyl isocyanate (HIC) using a newly developed initiator forming metal-enolate complex, sodium deoxybenzoin (Na-DB), is reported. For the polymerization of HIC, Na-DB serves the dual functions of providing controlled fast initiation and efficiently protecting the living chain ends. The use of Na-DB has resulted in quantitative polymer yields ($100%), effective control of the polymer's molecular weights, and low polydispersity index. To examine the living nature of poly(n-hexyl isocyanate) (PHIC), block copolymerization of HIC with another isocyanate monomer, 3-(triethoxysilyl)propyl isocyanate (TESPI), was carried out. The resulting block copolymer, poly(n-hexyl isocyanate)-b-poly(3-(triethoxysilyl)propyl isocyanate) (PHIC-b-PTESPI) was synthesized successfully via living anionic polymerization using Na-DB with quantitative yield and controlled molecular weight.

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Synthesis of Well‐Defined Rod‐Coil‐Rod Polyhexylisocyanate‐block‐polystyrene‐block‐polyhexylisocyanate via One‐Pot Anionic Polymerization

Ahn

Lee

2003

Macromol. Rapid Commun.

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A rod‐coil‐rod block copolymer, polyhexylisocyanate‐block‐polystyrene‐block‐polyhexylisocyanate, of controlled molecular weight was synthesized quantitatively via living anionic polymerization using potassium naphthalenide in the presence of sodium tetraphenylborate. The use of K+ as the counterion for the polymerization of styrene, and Na+ (NaBPh4) for the polymerization of isocyanate leads to the formation of a well‐controlled novel triblock copolymer. magnified image

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Anionic Polymerization of Chiral Isocyanate and Influence of the Initiator on Changes in the Optical Activity

Cited by 26 publications

References 8 publications

Generation of highly stable amidate anion in anionic polymerization of 3-(triethylsilyl)propyl isocyanate

Generation of highly stable amidate anion in anionic polymerization of 3-(triethylsilyl)propyl isocyanate

Enolate anionic initiator, sodium deoxybenzoin, for leading living natures by formation of aggregators at the growth chain ends

Synthesis of Well‐Defined Rod‐Coil‐Rod Polyhexylisocyanate‐block‐polystyrene‐block‐polyhexylisocyanate via One‐Pot Anionic Polymerization

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