High‐Performance Polybenzoxazine Nanocomposites Containing Multifunctional POSS Cores Presenting Vinyl‐Terminated Benzoxazine Groups

Abstract

We have prepared a new class of polybenzoxazine/POSS nanocomposites through the reactions of a multifunctional vinyl‐terminated VBa‐POSS with a VBa monomer at various compositional ratios. The incorporation of the silsesquioxane core units into the polybenzoxazine matrix significantly hindered the mobility of the polymer chains and enhanced the thermal stability of these hybrid materials. Increasing the POSS content in these hybrids improved their thermal and mechanical properties, relative to those of the neat polybenzoxazine, because of hydrogen bonding between the siloxane groups of the POSS core units and the OH groups of the polybenzoxazine moieties, as adjudged using FTIR spectroscopy.

Strong Screening Effect of Polyhedral Oligomeric Silsesquioxanes (POSS) Nanoparticles on Hydrogen Bonded Polymer Blends

“…This value of T g for PMA-POSS was close to that reported previously after living anionic polymerization [39]. The value of T g of poly(n-propyl methacrylate) (PPMA) has been reported to be approximately 35 °C; therefore, the increase in the glass transition temperature for PMA-POSS (to 59 °C) was presumably due to the nano-reinforcement effect of the rigid cubic silsesquioxane core of the POSS units on the PPMA segments, effectively restricting their molecular chain motion [40][41][42]. Figure 2a presents the second heating runs in our DSC analyses of PVPh/PMMA blends at various compositions; all blend compositions exhibited a single glass transition temperature over the entire range of compositions, indicating that they were fully miscible and featured a homogeneous amorphous phase.…”

Thermally curable main-chain benzoxazine prepolymers via polycondensation route

“…Similar improvement in the thermal stability was also reported polyhedral oligomeric silsesquioxane (POSS) and polybenzoxazine composites [63][64][65][66]. In a following study, we have described the chain extension of main chain benzoxazine-siloxane oligomers by cyclic siloxanes in the presence of tetrabutylammonium hydroxide (TBAH) as catalyst through the anionic polymerization route.…”

Mechanical and electret properties of polypropylene unwoven fabrics reinforced with POSS for electret filter materials

“…The cage can be thought of as the smallest spherical silica. POSS offer a unique opportunity for preparing organic-inorganic hybrid materials with the inorganic phase truly molecularly dispersed in the nanocomposites owing to their organic or inorganic substituent [17][18][19][20]. The chemical composition (RSiO 1.5 ) of POSS is similar to silica (SiO 2 ) and silicone (R 2 SiO) [21].…”