Phthalide cardo chain extended imine skeletal linked maleimido end capped nanotitania reinforced novel polybenzoxazine (nTiO2/PBZ) hybrid nanocomposites

A new class of nanotitania reinforced polybenzoxazine (nTiO2/PBZ) hybrid nanocomposites was synthesized using newly designed phthalide cardo chain extended imine skeletal linked maleimido end capped polybenzoxazine (PHM-PBZ) and nTiO2 through in-situ sol-gel method. The formation of hybrid nanocomposites was confirmed by NMR and FT-IR spectra. The structurally stable nTiO2 present in the nTiO2/PBZ hybrids accounted their exceptional thermal stability and good char yield. The restricted motion of flexible polymeric chain resulted from the inclusion of nTiO2 in the PBZ system increased the glass transition temperature ( T g) to a higher percentage than that of neat PBZ system. With the successive enhancement in the incorporation of nTiO2, the synthesized nanocomposites exhibited better thermal stability, higher flame retardancy and lesser water absorption behaviour than the of neat PBZ. The sequential increments in the loading level of nTiO2 onto the PBZ matrices caused the lower value of dielectric constant than that of neat PBZ. The homogeneity and successful dispersion of the nTiO2 fillers in the PBZ matrix were ascertained from the strong fluorescent emissions observed in the wavelength range of 300–550 nm through optical studies. Scanning electron microscope and transmission electron microscopic micrographs evidenced the successful incorporation of nTiO2 as can be seen from the different morphology at the nanoscale level in the PBZ matrix. This kind of structurally designed nTiO2/PBZ nanocomposites may find multifaceted applications in the form of adhesives, encapsulants, matrices and sealants and in the fields of automobile and microelectronics applications for better performance and longevity.

Beads on a Chain Fluorescent Oligomeric Materials: Interactions of Conjugated Organic Cross-Linkers with Silsesquioxane Cages

Organic electronic materials have advantages over inorganics in terms of versatility, cost, and processability. Recent advancements in organic materials for light-emitting diodes (OLED), field effect transistors (OFET), and photovoltaics have engendered extensive innovation potential on this field. In this research, we focus on synthesizing SQ (silsesquioxane) based oligomers cross-linked by dibromo-aromatic linkers and explore how the cross-linker influences their photophysical properties. Bis-trialkoxy silyl (linker) model compounds were synthesized to compare noncage photophysical properties with the oligomers. Several techniques such as UV/vis, fluorescence, FTIR, and thermal gravimetric analysis (TGA) have been used to characterize the systems. Time-resolved fluorescence and femtosecond transient absorption spectroscopy were used to understand the excited state dynamics of these materials. Studies were carried out to understand the differences between monomers and oligomers and potential energy transfer and charge transfer between the cages and cross-linking chromophores. Transient absorption showed lower energy absorption from the excited states, suggesting short-range communication between moieties. Single photon counting studies have shown distinct lifetime differences between most linkers and cages display possible excitation energy transfer through these materials. Transient absorption anisotropy measurements have shown signatures for excitation energy transfer between linker chromophores for oligomeric compounds. The silsesquioxane (SQ) backbone of the oligomers gives substantial thermal stability as well as solution processability, giving better flexibility for achieving energy transfer between linking chromophores.

Recent advances in the polymerization of elemental sulphur, inverse vulcanization and methods to obtain functional Chalcogenide Hybrid Inorganic/Organic Polymers (CHIPs)

Recent developments in the polymerization of elemental sulfur, inverse vulcanization and functional Chalcogenide Hybrid Inorganic/Organic Polymers (CHIPs) are reviewed.

The controllable construction and properties characterization of organic–inorganic hybrid materials based on benzoxazine-bridged polysilsesquioxanes

Some controllable morphology organic–inorganic hybrid materials have been prepared via the homopolymerization of benzoxazine-bridged polysilsesquioxanes precursors with different degrees of the triethoxysilane hydrolysis condensation.

Polynaphthoxazine-based 1D carbon nano-materials: electrospun fabrication, characterization and electrochemical properties

Polynaphthoxazine-based 1D carbon nano-materials were fabricated by a single-nozzle electrospinning process in a mixed polymer solution followed by curing and carbonization.