Smart and sustainable design of latent catalyst-containing benzoxazine-bio-resins and application studies

Abstract

A fully bio-based benzoxazine containing latent catalytic system is designed and successfully synthesized and it can be used as both an initiator and a beneficial property modifier of other thermosetting systems, especially for fire related properties.

Review on the Accelerated and Low-Temperature Polymerization of Benzoxazine Resins: Addition Polymerizable Sustainable Polymers

“…To reduce the carbon foot print, exploration of non-petrochemical feedstocks that are obtained naturally or in bio-wastes is actively sought both as solvent or solvent-free reactions [ 84 ]. These include cardanol (C) [ 85 , 86 , 87 , 88 , 89 , 90 ]; guaiacol (G) [ 89 , 91 , 92 ]; eugenol [ 93 , 94 ]; isoeugenol [ 95 ]; vanillin (V) [ 96 , 97 , 98 ]; umbelliferone (U) [ 99 ]; catechol [ 100 ]; cinnamic, ferulic, coumaric [ 101 , 102 ] and phloretic acid [ 101 , 103 , 104 ]; magnolol [ 105 ]; resveratrol [ 106 ]; humic acid (coal origin) [ 107 ]; daidzein [ 108 ]; naringenin [ 109 ]; arbutin-linked phenol [ 110 ]; levulinic acid based diphenolic acid [ 111 , 112 ]; sesamol [ 113 ]; apigenin [ 84 ] and amines such as stearylamine [ 93 ], dopamine [ 114 ], furfuryl amine (fa) [ 95 , 115 ], aminolysed poly(ethylene terephthalate) [ 116 ] and isomannide diamine (ima) [ 89 ], as shown in Figure 3 .…”

“…The presence of phenolic-OH sandwiched between the two oxazine rings in PG-fa monomer [ 343 ] and amide derivative of gallic acid-based main-chain benzoxazines revealed a latent effect [ 344 ]. Similarly, hydrogen-bonding between phenolic-OH and carbonyl motif in naturally occurring phenol, naringenin-based benzoxazine monomer, NA-fa, is accounted to have a latent effect and leads to a lower polymerization temperature, 166°C [ 109 ].…”

A naringenin-based benzoxazine with an intramolecular hydrogen bond as both a thermal latent polymerization additive and property modifier for epoxy resins

“…Recently, a few benzoxazines containing built-in latent catalytic functionality have been developed, 17,24,25 in which the intramolecular hydrogen bonding supports the latent form, which can still be broken upon heating to form a very reactive phenolic -OH that can activate the curing process at much lower temperatures than usual. Since these benzoxazines bear unreacted phenolic -OH groups, they are expected to react with epoxy resins in advance of the ring-opening polymerization of oxazine rings.…”

Innovative Hyperbranched Polybenzoxazine-Based Graphene Oxide—Poly(amidoamines) Nanomaterials

“…PBZ resins are produced via further thermal ring-opening polymerization (ROP) forming numerous –OH groups that are inter- and intramolecularly hydrogen bonded [ 6 , 7 ]. Although PBZs exhibit high glass temperature (Tg 170–340 °C), high char yield and better flammability resistance compared to conventional thermoset resins [ 1 ], the curing process takes place at relatively high temperatures (160–220 °C) restraining the usage of these polymers at industrial scale [ 8 ]. Thus, several strategies were developed in order to reduce the polymerization temperature by designing monomers with self-catalytic effect on the ROP as the –COOH and –OH groups showed effective contribution to accelerate the process [ 5 , 9 , 10 , 11 , 12 ].…”