This paper reports the development of the first vitrimer based on polybenzoxazines containing disulfide bonds and cardanol.

Phloretic acid: a sustainable building block to promote the solvent-free elaboration of benzoxazine and its polymerization into fully bio-based thermosets.

This work explores a new strategy, aiming for the synthesis of catalyst-free vitrimers by taking advantage of the abundant number of tertiary amines covalently bound into a polybenzoxazine network.

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This work reports the synthesis and successful use of novel benzoxazines as reinforcing resins in polyisoprene rubber compounds. For this purpose, three new dibenzoxazines containing one (4DTP-fa) or two heteroatoms of sulfur (3DPDS-fa and 4DPDS-fa) were synthesized following a Mannich condensation reaction. The structural features of each benzoxazine precursor were characterized by 1H and 13C nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) and Raman. The new precursors showed well suited reactivity as characterized by differential scanning calorimetry (DSC) and rheology and were incorporated in rubber compounds. After the mixing, the curing profiles, morphologies and mechanical properties of the materials were tested. These results show that the structural feature of each isomer was significantly affecting its behavior during the curing of the rubber compounds. Among the tested benzoxazines, 3DPDS-fa exhibited the best ability to reinforce the rubber compound even compared to common phenolic resin. These results prove the feasibility to reinforce rubber compounds with benzoxazine resins as a possible alternative to replace conventional phenolic resins. This paper provides the first guide to use benzoxazines as reinforcing resins for rubber applications, based on their curing kinetics.

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.