Fast cyclotrimerization of a wide range of isocyanates to isocyanurates over acid/base conjugates under bulk conditions

Wu, Li; Liu, Wei; Ye, Jinxing; Cheng, Ruihua

doi:10.1016/j.catcom.2020.106097

Cited by 8 publications

(6 citation statements)

References 32 publications

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“…N , N ′, N ′′-tris(3-dimethylaminopropyl)hexahydro-1,3,5-triazine (TDMAPHT) 7,42,43 provided more allophanate and less isocyanurate than TDMAMP (Fig. S2 and S3†), and [HTBD][OAc] 30 (a conjugate between 1,5,7-triazabicyclo [4.4.0] dec-5-ene and acetic acid), which catalyzes cyclotrimerization of isocyanates via synergistic hydrogen bonding functional catalytic mechanism, was deactivated most probably due to the presence of urethane groups in the mixture.…”

Section: Resultsmentioning

confidence: 99%

“…[HTBD][OAc] was synthesized following a literature procedure. 30 1,4-Butanediol was dried over mol-sieves, all other reagents were used directly without treatment. 4,4′-Methylene diphenyl diisocyanate (4,4′-MDI), polymeric MDI Lupranate® M20 (M20), N , N ′, N ′′-tris(3-dimethylaminopropyl)hexahydro-1,3,5-triazine (TDMAPHT), diethylene glycol bis-chloroformate (DGBCF), 1,4-diazabicyclo[2.2.2]octane (DABCO)-based urethane gel catalyst Lupragen® N202, PolyTHF® 2000 with molecular weight of 2000 g mol −1 (OH v = 56 mg KOH per g), and Lupraphen® 6601/2 with molecular weight of 2000 g mol −1 (polyester polyol synthesized from adipic acid, 1,4-butanediol and mono ethylene glycol, OH v = 56 mg KOH per g) were kindly provided by BASF Polyurethanes GmbH.…”

Section: Methodsmentioning

confidence: 99%

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Synthesis of polyisocyanurate prepolymer and the resulting flexible elastomers with tunable mechanical properties

Guo

Kleemann²,

Bokern³

et al. 2023

Polym. Chem.

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Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Synthesis of polyisocyanurate prepolymer and the resulting flexible elastomers with tunable mechanical properties

Guo

Kleemann²,

Bokern³

et al. 2023

Polym. Chem.

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show abstract

“…Another interesting acetate catalyst in which the cation plays an important role in cyclotrimerization of isocyanates was reported by Wu et al [50] In their work, various acid/base conjugates based on organocatalysis bases and the Brønsted acids were developed for cyclotrimerization of isocyanates. It was found that 1,5,7-triazabicyclo[4.4.0]non-5-ene-based (TBDbased) conjugates are efficient catalysts that complete the cyclotrimerization of p-tolyl isocyanate within seconds to minutes in yields that exceed 85 %.…”

Section: Chemcatchemmentioning

confidence: 99%

“…In dipolar aprotic solvents, tertiary amines are nucleophilic enough to catalyze cyclotrimerization of neat isocyanates. Wallis et al reported that during the reaction of phenyl isocyanate in polar solvents (DMF or DMSO) with tertiary amine such as 1,4diazabicyclo[2.2.2]octane (49) or 4-(dimethylamino)pyridine (50) as catalyst, triphenyl isocyanurate was obtained in more than 80 % yield. [71]…”

Section: Lewis Basic Catalystsmentioning

confidence: 99%

“…Another interesting acetate catalyst in which the cation plays an important role in cyclotrimerization of isocyanates was reported by Wu et al [50] . In their work, various acid/base conjugates based on organocatalysis bases and the Brønsted acids were developed for cyclotrimerization of isocyanates.…”

Section: Catalysts Operating Via Lewis Basic Cyclotrimerization Mecha...mentioning

confidence: 99%

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Catalysts for Isocyanate Cyclotrimerization

et al. 2023

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The formation of isocyanurate via cyclotrimerization of isocyanates is widely reported to provide a variety of polyurethane materials with improved chemical and physical properties such as weatherability, mechanical properties, thermal stability and flame retardancy. The demand for development of effective and selective catalysts for cyclotrimerization of isocyanates has been increasing. This review comprehensively summarizes catalysts for the cyclotrimerization of isocyanates that have been reported in peer‐reviewed publications and provides a valuable guideline for choosing suitable catalysts to match specific requirements. The catalysts are categorized into two main classes: catalysts operating via a Lewis basic cyclotrimerization mechanism and metal‐containing catalysts. Catalyst structures, reaction conditions, reaction time, catalytic effectivity as well as types of isocyanates whose trimerization is catalyzed are described in detail. In addition, featuring the findings and viewpoints from mechanistic studies, this review aims to stimulate the design and development of new, more efficient catalysts, and to guide further study of the trimerization mechanism with different classes of catalysts.

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Crystallization improvement of PLA by the talc with “grafting from” method of polymerization of lactide

Zhu,

Sun,

Meng

et al. 2024

J Polym Res

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The slow crystallization rate of polylactic acid (PLA) hampers its applications. By the "grafting from" method, a modi ed talcum powder (Talc-g-pla) was synthesized by the ring-opening polymerization (ROP) of lactide in bulk. The polymer chains grew in situ and chemically grafted on the talc surface, which was tightly connected even after washing with dichloromethane for 24 h. The Fourier transform infrared spectroscopy (FTIR), atomic force microscope (AFM), and the thermogravimetric analysis (TGA) of Talc-g-pla con rmed the successful modi cation of talc with PLA, which was about 2 wt%. Due to the good compatibility by the grafted PLA as a bridge between PLA and talc, the Talc-g-pla was well dispersed and served as an e cient nucleating agent of commercial PLA at low loadings. For the PLA/Talc-g-pla composite by the blend of Talc-g-pla with PLA in the proportions between 0.5-3.0 wt%, the differential scanning calorimeter (DSC) and polarized optical microscope (POM) showed that the improvement of thermodynamic properties and crystallization of PLA/Talc-g-pla composites were more obvious than those of the PLA/Talc physical composites. The DSC results suggested that the 1 wt% Talc-g-pla increased the crystallinity of PLA by over 3% than talc.

show abstract

Fast cyclotrimerization of a wide range of isocyanates to isocyanurates over acid/base conjugates under bulk conditions

Cited by 8 publications

References 32 publications

Synthesis of polyisocyanurate prepolymer and the resulting flexible elastomers with tunable mechanical properties

Synthesis of polyisocyanurate prepolymer and the resulting flexible elastomers with tunable mechanical properties

Catalysts for Isocyanate Cyclotrimerization

Crystallization improvement of PLA by the talc with “grafting from” method of polymerization of lactide

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