**9. Summary and conclusion**

In the present chapter, we have reviewed the synthesis of bio-based benzoxazine monomers with varying molecular design including mono, di, tri, tetra, hexa, and octa functional oxazine using renewable bio based raw materials such as cardanol, eugenol, guaiacol, vanillin, phloroglucinol, naringenin, apigenin, resveratrol, furfurylamine, stearylamine and etc. The present chapter also discusses the preparation of polybenzoxazine bio-composites using bio-silica, silica particle through sol–gel approach and boron complexes and their thermal and flame resistant properties using various characterization techniques including LOI, UL-94 vertical flame test, smoke density, SEM analysis, and MCC. Data obtained from the thermal and flame resistant analysis, the newly developed resveratrol, phloroglucinol, naringenin, apigenin based multi-functional benzoxazine has greatest prospective applications as anti-flammable and fire resistant matrix for advanced composites for several applications. Especially, the HRC and TRC value of poly(RES-ac) is ominously lower than that of the thermosets from ortho-amide and ortho-imide benzoxazines, which exhibited one of the lowest HRC values of all polymers. Thus, this newly developed resveratrol-based tri-benzoxazine monomer containing acetylene group has greatest prospective applications as anti-flammable and fire resistant matrix for advanced composites. Consequently, these developments might be very useful in fabricating new products for the next generation's high-performance and flame retardant uses by exploiting eco-friendly, sustainable and cost competitive bio-based polybenzoxazine matrices and composites for varying range of industrial and engineering applications.

*Flame Retardant and Thermally Insulating Polymers*
