Latent curing of epoxy-thiol thermosets

POLYMER

卷:116

Article

Konuray, Ali Osman¹  Fernandez-Francos, Xavier¹  Ramis, Xavier¹ 

[1] Univ Politecn Cataluna, ETSEIB, Thermodynam Lab, Ave Diagonal 647, E-08028 Barcelona, Spain

关键词: Epoxy-thiol;    Click reaction;    Curing kinetics;    Photobase;    Latency;   

DOI  :  10.1016/j.polymer.2017.03.064

来源: Elsevier

【 摘 要 】

Epoxy-thiol curing is a click reaction which allows quantitative yield of the end products. The basecatalyzed reaction is rapid at low temperatures so it is most often desirable to harness reactivity by using latent catalysts. In this work, we used triazabicyclodecene tetraphenylborate (TBD center dot HBPh4) as a photobase generator (PB). We activated the PB either thermally or by UV light and monitored reaction kinetics by DSC and FTIR methods. Depending on the catalytic system used, the rate of the thiol-epoxy reaction was ordered as follows: Neat base > UV activated PB > thermally activated PB > uncatalyzed system. A series of isothermal and non-isothermal DSC experiments were run on non-irradiated and irradiated samples in order to study the effect of PB content and UV irradiation duration on PB activation efficiency and latency/storage stability. The data from DSC were analyzed using model-free linear iso-conversional methods to estimate kinetic parameters such as activation energies. In addition, the kinetics data for both activation methods were shown to be accurately represented by multi-term Kamal models. The storage stability of the systems were studied at room temperature and was shown to fit well to the predictions of the kinetic model. (C) 2017 Elsevier Ltd. All rights reserved.

【 授权许可】

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