Synthesis and characterization of new polybenzoxazines from renewable resources for bio‐composite applications

Abstract

Renewable natural resources such as eugenol, furfurylamine, stearylamine, and jute fiber were used to prepare polybenzoxazine composites. The purity of eugenol which is extracted from clove was confirmed by gas chromatography. FTIR, 1H, and 13C NMR spectroscopic analysis were used to determine the structure of eugenol and the benzoxazine monomers namely 6‐allyl‐3‐furfuryl‐8‐methoxy‐3,4‐dihydro‐2H‐1,3‐benzoxazine (EF‐Bz) and 6‐allyl‐3‐octadecyl‐8‐methoxy‐3,4 dihydro‐2H‐1,3‐benzoxazine (ES‐Bz) synthesized from it. The curing analysis from differential scanning calorimetric analysis shows that the onset of curing is shifted to lower temperature (161°C) for EF‐Bz, when compared with ES‐Bz (174°C). The thermal stability analyzed from thermogravimetric analysis shows that the polybenzoxazine EF‐Pbz has higher thermal stability (T5% = 361°C) with that of ES‐Pbz (T5% = 313°C). The storage modulus, tensile, and flexural strength of the EF‐Bz/Jute fiber composite show high value when compared with ES‐Bz/Jute fiber composites. POLYM. COMPOS., 37:1821–1829, 2016. © 2014 Society of Plastics Engineers

Synthesis of Eugenol-Based Silicon-Containing Benzoxazines and Their Applications as Bio-Based Organic Coatings

“…Their Tg ranged from 89 to 123 °C, which was lower than the conventional polybenzoxazine resins' Tg. However, when compared with the main-chain type polybenzoxazines reported in the literature [56,57], the Tg of 123 °C were higher than or comparable with them. For example, Zhang et al prepared a bio-based main-chain type polybenzoxazine whose Tg was 113 °C.…”

“…Figure 6b showed the DSC curves for poly (SIE-e), poly (SIE-b), and poly (SIE-d) after the curing reaction and no more exothermic peaks were observed in the range of 200-250 • C, which confirmed the full polymerization of oxazine rings. However, a deviation of the base line was observed for all the systems when the temperature was increased to higher than 270 • C, which might be caused by the post-curing or the thermal degradation of cured resins at higher temperature [32,56].…”

Cardanol and Eugenol Sourced Sustainable Non-halogen Flame Retardants for Enhanced Stability of Renewable Polybenzoxazines

“…The synthesis of cardanol and eugenol derived benzoxazines have been reported extensively in the literature. Depending on the functionality of the amine used, the resultant benzoxazine monomer showed mono- (Attanasi et al, 2012;Thirukumaran et al, 2014aThirukumaran et al, , 2016a bis- (Attanasi et al, 2012;Lligadas et al, 2014;Thirukumaran et al, 2014b;Dumas et al, 2015;Amarnath et al, 2019), tris- (Shukla et al, 2015), tetra- (Shukla et al, 2015), hexa- (Amarnath et al, 2018a), and octa-oxazine (Periyasamy et al, 2015) functionality. Similarly, for phenols, petroleum based amines are also being substituted by bio-based amines, such as furfurylamine, stearylamine, aminolysed poly(ethylene terephthalate), and isomannide diamine (ima) toward the synthesis of fully-sustainable benzoxazine monomers (Wang et al, 2012;Froidevaux et al, 2016;Sharma et al, 2016;Thirukumaran et al, 2016b;Amarnath et al, 2019).…”

Preparation and flame retardancy of flax fabric/polybenzoxazine laminates

“…12 By combining PBz resin with natural fibres, low environmental impact composites with advantageous performances are consequently expected to be obtained. Different studies have evaluated the effect of different loading of hemp, [13][14][15] jute, 16,17 sisal, 18 kenaf, 19 or bamboo 20 fibres (short fibers were conisdered in those studies) on the curing behaviour of the Bz resin and on the mechanical performances of the composites before and after accelerated weathering and their thermal properties. Benefits are generally observed in terms of mechanical performances but the composites present lower thermal stability than the PBz alone because of the low temperature of decomposition of the fibres.…”