Hydrogen bonding interactions and miscibility between phenolic resin and octa(acetoxystyryl) polyhedral oligomeric silsesquioxane (AS‐POSS) nanocomposites

Abstract

We have synthesized a polyhedral oligomeric silisesquioxane (POSS) derivative containing eight acetoxystyryl functional groups [octa(acetoxystyryl)octasilsesquioxane (AS‐POSS)] and then blended it with phenolic resin to form nanocomposites stabilized through hydrogen bonding interactions between the phenolic resin's hydroxyl group and the AS‐POSS derivative's carbonyl and siloxane groups. One‐ and two‐dimensional infrared spectroscopy analyses provided positive evidence for these types of hydrogen bonding interactions. In addition, we calculated the interassociation equilibrium constant, based on the Painter–Coleman association model (PCAM), between phenolic resin and POSS indirectly from the fraction of hydrogen‐bonded carbonyl groups; quantitative analyses indicate that the hydroxyl–siloxane interassociation from the PCAM is entirely consistent with the classical Coggesthall and Saier (C and S) methodology. From a thermal analysis, we observed that the miscibility between phenolic and AS‐POSS occurs at a relatively low AS‐POSS content, which characterizes this mixture as a polymer nanocomposite system. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 673–686, 2006

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

“…As a result, the C=O groups of PMA-POSS could not interact through intermolecular hydrogen bonding with the OH groups of the hydrogen bond donor compounds. This behavior presumably arose for two main reasons: (i) the inter-association equilibrium constant between the OH groups and the POSS units (K A = 38.6) [47,48] being greater than that between the OH and C=O groups (K A = 20) [25]; (ii) strong aggregation of the POSS nanoparticles on the PMMA side chains. We also tested the effect of increased temperature on the hydrogen bonding interactions in the phenolic/PMA-POSS blend ( Figure 12).…”

Surface energetics, dispersion, and nanotribomechanical behavior of POSS/PP hybrid nanocomposites

“…In general, hybridization of an organic polymer matrix with inorganic POSS results in improved thermal and mechanical properties along with increase in oxidative and flame resistance. [3][4][5][6][7][8]11 Recently Nanda et al 12 synthesized well dispersed polyurethane/POSS hybrid materials utilizing a solution polymerization process. Ordered morphologies with homogenously distributed POSS domains ($100-150 nm) were observed.…”

“…Over the last decade POSS has been copolymerized with multiple monomer systems to produce a wide range of thermoplastics and thermosets with POSS molecules incorporated as an integral part of the polymer chain. [1][2][3][4][5][6][7][8][9] The majority of these research efforts are focused on improving thermomechanical performance of the polymer matrix through uniform molecular level POSS nanoparticle dispersion achieved by directly incorporating POSS moieties into the polymer chain. 9,10 Thermomechanical properties are reported to be strongly influenced by the structure and concentration of the POSS moieties, POSS-POSS interactions and POSS-polymer interactions.…”

The Self‐Assembled Structure of the Diblock Copolymer PCL‐b‐P4VP Transforms Upon Competitive Interactions with Octaphenol Polyhedral Oligomeric Silsesquioxane

“…[33][34][35] OP-POSS was synthesized through a simple two-step synthesis: hydrosilylation of 4-acetoxystyrene with octasilane POSS (Q 8 M H 8 ) and subsequent hydrolysis of the acetoxy units. [25][26][27][28] Block Copolymer/NP Preparation Blend samples that contained various molar fractions of PCL-b-P4VP and OP-POSS were prepared through solution casting. A N,Ndimethylformamide (DMF) solution that contained 5 wt.-% of the blend was stirred for 8-10 h and then cast on a Teflon dish.…”

“…[21][22][23][24] In previous studies, we developed a simple two-step synthesis of OP-POSS through hydrosilylation of 4-acetoxystyrene with octasilane POSS (Q 8 M H 8 ), and subsequent hydrolysis of the acetoxy units. [25][26][27][28] OP-POSS possesses eight phenolic groups, which form hydrogen bonds with several hydrogen-bonded acceptor groups (e.g., pyridine, C¼O, ether, and ester units). The hydrogen-bonding interactions in phenol/ P4VP blends (K A ¼ 598) [29] are significantly stronger than those in phenol/PCL blends (K A ¼ 90), [30,31] based on the Painter-Coleman association model (PCAM).…”