Sorbitol–POSS Interactions on Development of Isotactic Polypropylene Composites

Abstract

This study investigates the nature of interactions between the molecules of polyhedral oligomeric silsesquioxane (POSS) containing silanol functionalities (silanol–POSS) and di(benzylidene)sorbitol (DBS) encountered in the development of nanocomposite fibers from the compounds of POSS, DBS, and isotactic polypropylene (iPP). The interactions were investigated using Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry, and oscillatory shear rheology. Mass and NMR spectrometry revealed that the molecules of silanol–POSS and DBS formed several amorphous noncovalent molecular complexes promoted by hydrogen bonding. More abundant complex formation was observed with silanol–POSS molecules carrying four silanol groups and phenyl substitutions. Such complex formation deterred fibrillation of DBS when the compounds of iPP, DBS, and silanol–POSS were cooled from homogeneous melt states. It was also revealed that POSS–DBS complexes were of much lower viscosity than iPP.

Polyhedral oligomeric silsesquioxane/polyamide bio-nanocomposite membranes: structure-gas transport properties

“…Similar type of dispersions were observed by Ayandele et al 11 and Roy et al 48 This increased the compatibility between the two components, leading to a nanosized dispersion of some POSS molecules. The TEM images showed slight increase in the aggregation pattern on increasing the POSS content from 5% to 20%.…”

Tandem mass spectrometry of electrosprayed polyhedral oligomeric silsesquioxane compounds with different substituents

“…Great progress in the characterization of POSS species has been made with the use of mass spectrometry (MS), which allows the degree of intramolecular condensation to be readily determined from their MS spectra. [6] The production of intact ionized POSS molecules in the gas phase is usually achieved using matrix-assisted laser desorption/ionization (MALDI) [6][7][8][9][10][11][12][13][14][15][16][17][18] or electrospray ionization (ESI), [9,10,14,15,[19][20][21][22] although the use of alternative soft techniques such as fast atom bombardment (FAB) [23,24] or atmospheric pressure chemical ionization (APCI) [19,25] has also been reported. Despite the increasing number of studies involving mass spectrometry as an efficient tool to characterize these compounds, the activation of ionized POSSs to characterize their fragmentation pathways has rarely been documented.…”

Polypropylene‐based composites containing sorbitol‐based nucleating agent and siloxane‐silsesquioxane resin

“…An alternative approach consists of combining commercially used nucleating agents with organic–inorganic materials . Roy et al . reported that the molecules of silanol silsesquioxanes and a sorbitol derivative, namely di(benzylidene)sorbitol, are capable of forming several complex molecular adducts, due to noncovalent interactions, i.e., hydrogen bonding.…”