Tailor-made and chemically designed synthesis of coumarin-containing benzoxazines and their reactivity study toward their thermosets

Abstract

Coumarins are used as a natural renewable resource to synthesize coumarin-containing benzoxazine resins. The coumarin-containing benzoxazines are fully characterized in terms of their chemical structure by Fourier-transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy. The influence of electronic effects caused by the substituents on the polymerization temperature is also evaluated. Thermal properties of the resulting thermosets are characterized by differential scanning calorimetry and thermogravimetric analysis, showing good stability and char yields higher than 50%.The coumarin-containing polybenzoxazine thermosets show T g values in the range between 160 and 190 8C. Thus, the herein presented coumarin-containing benzoxazine resins are proven to be competitive monomers when compared with other petroleum-based benzoxazine resins toward the generation of high-performance thermoset.

Influence of Poly(ε‐caprolactone) Molecular Weight and Coumarin Amount on Photo‐Responsive Polyurethane Properties

“…The neat PUs showed typical glass transition temperature, T g , values of PCL in the range –55 °C to –45 °C and the T m at around 40–50 °C . The T g values increased with CD amount for all PU formulations, due to CD increasing the steric restriction toward molecular rearrangements and thus impairing polymer chain mobility, which leads to a higher value of T g . PU530s exhibited their melting transitions at lower temperatures than their PU2000s counterparts due to their shorter chains and smaller PCL crystal sizes…”

“…[40] The T g values increased with CD amount for all PU formulations, due to CD increasing the steric restriction toward molecular rearrangements and thus impairing polymer chain mobility, which leads to a higher value of T g . [7] PU530s exhibited their melting transitions at lower temperatures than their PU2000s counterparts due to their shorter chains and smaller PCL crystal sizes. [41] The introduction of CD did not significantly modify T m values of PU530s but it considerably reduced the crystallinity, shown by a decrease in the melting enthalpy (Table 2).…”

“…Photo‐reversible polymers have attracted much attention in the last few years due to their photo‐responsiveness, which gives the ability to build up reversible crosslinked networks under UV light, that is, under the natural illumination of the low concentration UV component of sunlight or under artificial successive UV light irradiations . They can be processed in several forms, i.e., as films, coatings, hydrogels, or aerogels, and have attracted interest in many industrial sectors for applications including biosensors, adhesives, chemical storage, coatings for the automotive industry, drug delivery, and for self‐healing purposes . Since crosslinked materials are difficult to recycle, photo‐reversible materials also have importance in facilitating recycling or reusability .…”

Biobased Benzoxazine Derived from Daidzein and Furfurylamine: Microwave‐Assisted Synthesis and Thermal Properties Investigation

“…[15] Up to now,alarge quantity of biobased benzoxazines have already been prepared from the renewable cardanol, [16,17] diphenolic acid, [18,19] phloretic acid, [20] furfurylamine, [21,22] stearylamine, [23] coumarin, [24,25] umbelliferone, [26] and more recently the lignin derivatives (guaiacol, [27][28][29][30] vanillin, [31][32][33] and eugenol [34][35][36][37][38] ). [15] Up to now,alarge quantity of biobased benzoxazines have already been prepared from the renewable cardanol, [16,17] diphenolic acid, [18,19] phloretic acid, [20] furfurylamine, [21,22] stearylamine, [23] coumarin, [24,25] umbelliferone, [26] and more recently the lignin derivatives (guaiacol, [27][28][29][30] vanillin, [31][32][33] and eugenol [34][35][36]…”

Bio‐based benzoxazines based on sesamol: Synthesis and properties

“…For instance, arbutin, furfurylamine, and paraformaldehyde were used to synthesize a water‐soluble benzoxazine by Dubois . Coumarin was used to synthesize a series of bio‐based benzoxazines by Ishida, who found that monomers based on coumarin are photopolymerizable and that the surfaces of corresponding polymers have good hydrophobicity . Cádiz synthesized a series of tough benzoxazine resins using castor oil, and eugenol was used to synthesize a series of bio‐based benzoxazines and composite materials by Thirukumaran et al .…”