Synthesis and characterization of benzoxazine‐based phenolic resins: Crosslinking study

Abstract

Modified novolac resins with benzoxazine rings were prepared. The synthetic method involved the preparation of 1,3,5-triphenylhexahydro-1,3,5-triazine as an intermediate that further reacts with the novolac resin. The catalytic effects of phenols, carboxylic acids, and Lewis acids on the benzoxazine ring-opening polymerization were shown. The curing behavior of the benzoxazine compounds and the thermal properties of the cured resin were studied, and the results indicated improved degradation behavior for flammability. V-0 materials were obtained when the materials were tested for ignition resistance using the UL-94 test.

Novel phosphorilated flame retardant thermosets: epoxy–benzoxazine–novolac systems

“…In previous studies, we modified novolac resins with benzoxazine rings and investigated the curing behaviour and properties of the cured resins [9]. We showed that the presence of phenolic groups decreases the curing temperature of the benzoxazine-novolac resins.…”

“…The results of the burn tests are shown in Table 3. Our previous results [9] showed that high modification degree on novolac-benzoxazine systems causes a decrease in flame retardance and NB2 with 80% of benzoxazine moieties exhibit a V-1 grade. The same occurs in the present phosphorous-free resins such as NBH systems while all phosphorous-containing resins produce a V-0 material (NBI and NBIH systems).…”

“…In a previous study, we synthesized modified novolac resins with benzoxazine rings and studied the catalytic effect of phenolic free groups on the benzoxazine ring opening polymerization [9]. The copolymerization of these benzoxazine-novolac systems with epoxy resins requires high amounts of epoxy resins if the mechanical and thermal properties are to be good.…”

Integrating plant oils into thermally curable main-chain benzoxazine polymers via ADMET polymerization

“…The 1,3,5-triphenylhexahydro-1,3,5-triazine and methyl 10-undecenoate (UDM) were synthesized according to a reported procedures [31,32,33]. All solvents were purified by standard procedures.…”

Fatty acid-derived α,ω-bis-benzoxazines through hydrosilylation; curing and thermoset properties

“…1,3,5-triphenylhexahydro-1,3,5-triazine [21,22] was synthesized according to reported procedures. All solvents were purified and dried by standard methods.…”