Multivalent photo-crosslinkable coumarin-containing polybenzoxazines exhibiting enhanced thermal and hydrophobic surface properties

Abstract

Mono-, bi-, and trivalent coumarin-containing benzoxazine monomers were synthesized by facile Mannich reactions of 4-methyl-7-hydroxycoumarin and paraformaldehyde with aniline, bisphenol A–NH2, and 1,3,5-tri(4-aminobenzene).

Well-defined benzoxazine/triphenylamine-based hyperbranched polymers with controlled degree of branching

“…3,29 Benzoxazine (BZ) monomers possess the ability to undergo thermal ring-opening polymerization, without the need for any catalysts and without the formation of byproducts, forming polymers with several unique features (e.g., high chemical resistance, low surface free energy, high ame retardancy) that have drawn the attention of both academia and industry. [30][31][32][33][34][35][36][37] Triphenylamine (TPA) possesses a unique two-photon absorption ability and has been studied and applied in many elds, including optoelectronic devices and electron transition devices. [38][39][40] Hence, we have been interested in combining the properties of BZ and TPA units in polymeric systems.…”

Light-switchable nanoparticles based on amphiphilic diblock, triblock and heterograft polyoxazoline

“…7,8 In comparison to other strategies, photo-crosslinking is an attractive way because rapid, effective and well-controlled process without by-product formation. [9][10][11][12][13] Among various photo-crosslinkable molecules, coumarin and its derivatives have attracted considerable attention. [14][15][16] They photo-dimerize according to a [2p + 2p] cyclo-addition under UV-irradiation at l > 310 nm.…”

Photo-sensitive benzoxazine II: chalcone-containing benzoxazine and its photo and thermal-cured thermoset

“…Polybenzoxazines exhibit special characteristics such as moderate-to-high thermal properties, [1][2][3][4][5][6][7][8][9][10][11][12][13][14] superior membrance properties at elevated temperatures, 15 low shrinkage, 16 and low surface energy. 17 To further enhance their properties, studies on the curing mechanism, 5,7,[18][19][20][21] incorporation of a multifunctional linkage [22][23][24][25] or photo-sensitive moieties such as methacryloyl 26,27 and coumarins [28][29][30] have been applied. It is known that the coumarin moiety undergoes dimerization through [2p + 2p] cycloaddition to afford a crosslinked network upon irradiation at wavelengths greater than 310 nm.…”

“…Kuo et al prepared a coumarin-containing benzoxazine (coumarin-Py Bz). 29,30 They dimerized the coumarin-Py Bz to a dimer, the di-coumarin-Py Bz, through photodimerization of the coumarin moiety. DSC thermograms revealed that the glass transition temperature of poly(dicoumarin-Py BZ) is 227 C, which is higher than that (200 C) of poly(coumarin-Py BZ), a thermoset of coumarin-Py Bz without photodimerization.…”

“…To the best of our knowledge, no chalcone-containing benzoxazine has been reported in literature. Continuing other's and our effort in developing photo-sensitive benzoxazines, [28][29][30][31][32] we prepared a chalcone-containing benzoxazine, the 1,3-bis(4hydroxyphenyl) propanone/aniline/formaldehyde-based benzoxazine (BHP-a, n ¼ 0 in Scheme 1) and evaluated the properties of its thermosets. Solubility test shows that the double bond of chalcone is thermally reactive.…”