Temperature-Dependent Enhancement Effects for TBD (1,5,7-Triazabicyclo[4.4.0]dec-5-ene) with 2-Methylimidazole-Intercalated α-Zirconium Phosphate as a Latent Thermal Initiator in the Reaction of Glycidyl Phenyl Ether

Osamu Shimomura,Suguru Sasaki,Kaori Kume,Atsushi Ohtaka,Ryôki Nomura

doi:10.3390/inorganics7070083

Osamu Shimomura, Suguru Sasaki + Show 3 more

Open Access

https://doi.org/10.3390/inorganics7070083

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Journal: Inorganics	Publication Date: Jun 30, 2019
Citations: 2	License type: CC BY 4.0

Affiliation: Osaka Institute of Technology

Abstract

The catalytic effects of 1,1,3,3-Tetramethylguanidine (TMG), 1,5,7-Triazabicyclo[4.4.0]dec-5-ene (TBD), 7-Methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD), 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), and 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) in the reaction with glycidyl phenyl ether (GPE) at 40 °C were investigated. For the reaction, the %conversion of GPE was only 11%, carried out at 40 °C over 14 days in the presence of TBD.Additionally, there was little catalytic activity for the same reaction performed under typical storage conditions at 25 °C. The effect of TBD with 2-methylimidazole-intercalated α-zirconium phosphate (α-ZrP∙2MIm), as a latent thermal initiating system in the reaction with GPE, was then examined. The reaction did not proceed within 1 h at 80 °C. On increasing the temperature to 120 °C, the %conversion reached 75% for reaction at 1 h. Under typical storage conditions (7 days at 25 °C), the %conversion of GPE was only 7%. With addition of TBD to α-ZrP∙2MIm, reagent stability was maintained, and the polymerization reaction proceeded rapidly with the application of heat.

Highlights

There has been considerable interest in the development of latent polymerization catalysts and initiators that are inert in monomer or prepolymer systems under typical storage conditions
We have previously reported that primary alkylamines intercalated with α-zirconium phosphate (α-ZrP) may serve as latent thermal initiators in the reaction of glycidyl phenyl ether (GPE) [11,12], and that the compounds 1,4-diazabicyclo[2,2,2]octane (DABCO), 1,8-diazabicyclo[5,4,0]undec-7-ene (DBU), imidazole (Im), 2-methylimidazole (2MIm), 2-ethyl-4-methylimidazole (2E4MIm), and benzimidazole (Bim) intercalated with α-ZrP show good performance as latent thermal initiators in the reaction of GPE
%conversion value was 28% for α-ZrP∙2MIm-T, whereas a reaction did not occur for the addition of effects of TBD, the reactions were performed for 9 h at 100 °C (Figure 2b)

Summary

Introduction

There has been considerable interest in the development of latent polymerization catalysts and initiators that are inert in monomer or prepolymer systems under typical storage conditions. Latent thermal initiators must remain inactive under storage conditions, but show high activity at specific temperatures [1,2,3,4,5,6,7,8,9,10]. Inorganics 2019, 7, x FOR PEER REVIEW performance as latent thermal initiators in the reaction of GPE with hexahydro-4-methylphthalic anhydride important a highly active latent initiating. It is important to develop a highly active latent initiating compound, we have studied enhancement effects bases with α-ZrP∙2MIm a potential system to avoid the need forthe high-temperature curing.ofTherefore, using. Compound, we have studied the enhancement effects of bases with α-ZrP∙2MIm as a potential highly active latent initiating system to avoid the need for high-temperature curing. As a model and epoxy compound, we have studied the enhancement effects of bases with α-ZrP·2MIm as a

Results

Results and of Discussion

Reaction

Withvalues respect storage and

Measurements the following operating conditions

Typical Polymerization Procedure

Conclusions