Design and Synthesis of Bio-Based Benzoxazines

Abstract

Polybenzoxazine (PBz) resins are a new type of high-performance synthetic resins that are attractive alternatives to traditional resins. Their properties include near-zero shrinkage upon polymerization, fast evolution of mechanical properties with the conversion, glass transition temperatures much higher than curing temperatures, low water absorption, and excellent dielectrical and mechanical properties. The development of polybenzoxazines has always been linked to petro-based feedstocks, but for the last 5 years, the number of studies related to bio-based benzoxazines is exploding as a consequence of the versatility of the design of the chemical structure of their monomers. Benzoxazine (Bz) monomers are subjected to cationic ring-opening polymerization (ROP), activated by a thermal treatment in the range of 160-250°C. In addition, Bz synthesis promotes the use of naturally occurring phenolic compounds instead of petroleum-based ones to develop high-performance materials from renewable resources and to fit to REACH restrictions. For this purpose, vanillin, eugenol, and cardanol are examples of bio-phenols bridged with several kinds of aromatic and aliphatic diamines. In this chapter, the synthesis and the properties of di-functional benzoxazine monomers prepared from naturally occurring phenolic compounds are reviewed. Symmetric and asymmetric monomers will be detailed. The last part of the chapter is dedicated to the use of bio-phenols to functionalize polymers and to provide benzoxazine functional groups.

High‐Performance Vitrimeric Benzoxazines for Sustainable Advanced Materials: Design, Synthesis, and Applications

“…Many benzoxazines based on vanillin have been synthesized and characterized. [4,132,[147][148][149][150][151][152][153][154] Other widely used biobased benzoxazine precursors include eugenol, [149,150,[153][154][155][156][157] obtained from clove oil, nutmeg, cinnamon, basil and bay leaf, [157] cardanol, [10,11,123,129,149,156,[158][159][160][161] which can be obtained from cashew nut shell, [10,123,158,159] and guaiacol [153,154,162,163] obtained from pyrolysis of biomass. [162,163] Apart from benzoxazines synthesized from the most widely used biobased phenols, other sustainable benzoxazines are reported, including those derived from rosin, obtained from the exudation of pines and conifers, [164] resveratrol (a triphenol compound extracted from grapes, pines, legumes, and other plants), [165] and chavicol [166] (derived from bay oil, sweet basil, or betel oil).…”

Polybenzoxazine‐hazelnut shell composites: Curing behavior, thermal stability, mechanical properties, and material stress analysis

“…Meanwhile, the brittleness of composites, which is always a major weakness for BA-a, is reduced, broadening the usage of BA-a in the industry where high ductility is required. [34,35] A high percentage of lignin group with OH present in the HS particles formed the hydrogen bonding with matrix, the mechanical properties of the HS filled composites are increased by helping the chain reaction with matrix. [36]…”

High Temperature Composites From Renewable Resources: A Perspective on Current Technological Challenges for the Manufacturing of Non-Oil Based High Char Yield Matrices and Carbon Fibers

“…They are produced by the combination of derivative phenols, primary amines and formaldehyde (Zhang et al, 2019). The ring-opening polymerization of benzoxazines, that take place at high temperature, is able to produce polymers having both phenolic hydroxyl and tertiary amine functionalities (Trejo-Machin et al, 2018). It is reported in the literature that biobased benzoxazines can be prepared from guaiacol (from lignin source), paraformaldehyde (from oxidized biomethanol), and furfurylamine (from furfural).…”