Chapter 39 - Polybenzoxazine-Based Organic-Inorganic Nanohybrid Materials for High Performance Engineering Applications

Abstract

In the present chapter, synthesis and spectral analysis of new benzoxazine monomers namely BHC-al, BHC-acol and (PH-aea2-8) were discussed. In addition to the monomers preparation, POSS derivatives namely OMPS and OGPOSS synthesis were also discussed. Development and properties of organic inorganic nanohybrids resulted from the combination of Poly(BHC-al)/OMPS, Poly(BHC-acol)/OMMT clay and Poly(BHC-acol)/OGPOSS were studied in detail. Further, the synthesis and properties of aliphatic ether linked polybenzoxazine matrices [poly(PHaea2-8)] were studied with respect to their carbon chain. Properties like thermal were dielectric studied. In the mid of various nanohybrids, composites developed with 7.5 wt % OGPOSS incorporated poly(BHC-acol), was found to exhibit the highest thermal stability with 17.6 % char yield at 800 °C and Tg value as 221°C. In addition, the same composite was also found to have the lowest dielectric constant (2.12). However, on the other hand the 7.5wt% OMMT clay-reinforced poly(BHC-acol) nanocomposites deliver the highest dielectric constant (4.74). Further, micrograph analysis and their morphology were discussed using SEM, TEM and XRD results. Data that resulted from dielectric and thermal studies indicate that the poly(BHC-acol)/OGPOSS nanocomposite could be used as an effective low dielectric material for microelectronic applications with high thermal stability. The synthesis of a series of new Polybenzoxazine poly(PH-aea2-8) matrices using monomers with aliphatic ether link backbones (PH-aea2-8) were discussed. Here, two synthetic protocols were used namely conventional and ultrasonication. It is found that the ultrasonication technique seems to be a more facile method for the synthesis of benzoxazine monomers compared to the conventional method. Futher, it is also noted that a significant improvement in toughness was obtained with an increase in the aliphatic ether linkage chain length. Thus, these newly developed series of poly(PH-aea2-8) matrices can be used as advanced materials for a wide range of high performance engineering applications in the form of sealants, coatings, matrices, and composites.