Hansen Solubility Parameters for Octahedral Oligomeric Silsesquioxanes

Abstract

The Hansen Solubility Parameters (HSP) for several polyhedral oligomeric silsesquioxane (POSS) compounds were successfully determined, demonstrating the applicability of the HSP approach for selected types of organic−inorganic compounds. As commonly practiced with organic polymers, a set of simple "pass/fail" tests for complete solubility at a fixed concentration (100 mg/mL) was conducted for an array of five octameric POSS compounds, octa(phenethyl), octa(styrenyl), octa(isobutyl), octakis(hexafluoroisobutyl), and (1-naphthyl)heptaphenyl), and 45 test solvents. Group contributions for the octameric POSS cage were determined using three different approaches, which produced similar results. The best cage contribution estimate for the dispersive, polar, and hydrogen-bonding components δ D , δ P, , and δ H of the total solubility parameter was determined to be δ D = 22 (J/cc) 1/2 , δ P = 19 (J/cc) 1/2 , and δ H = 15 (J/cc) 1/2 , with an estimated uncertainty of approximately 5 (J/cc) 1/2 . The utility of the HSP approach was demonstrated by successfully identifying mixtures of poor solvents that provided significantly enhanced solubility for octa(isobutyl) POSS, and by successfully estimating the HSP of octakis(trifluoropropyl) POSS from group contributions derived solely from aromatic POSS compounds.

Solubility of N,N′-Di(1-naphthyl)-N,N′-diphenyl Benzidine (NPB) in Various Organic Solvents: Measurement and Correlation with the Hansen Solubility Parameter

“…[3][4][5][6][7][8]12,13,[15][16][17][18][19][20][21][22][23][24][25][26][27] The solubility parameter in its original Hildebrand form  (MPa 1/2 ) is defined as the square root of the cohesive energy density:…”

“…[4][5][6][7]12,[18][19][20][21][22][24][25][26][27] This method is based on the principle that good solvents are located within a threshold radius 0 R from the solute ( Figure 1. Solubility of NPB in organic solvent was determined from the UV absorbance of saturated solution prepared in the following procedure.…”

Star-shaped POSS diblock copolymers and their self-assembled films

“…1,2 Normally, POSS contains a silsesquioxane cage with the formula (SiO 1.5 ) n (n ¼ [8][9][10][11][12][13][14] and n organic functional groups originating at each Si atom on a cage vertex. 3,4 Therefore, functionality may vary from one organic group to another, [5][6][7][8] and will lead the reactive combination of POSS into polymers designed as branched, 9,10 starshaped, 11,12 or core-shell 13,14 structures to obtain hydrophobicity or high mechanical and thermal properties. [15][16][17][18] In fact, POSS cube can be incorporated into the polymeric system by blending, 19,20 graing, 21,22 cross-linking 23,24 and copolymerization.…”

Functional Polyimide/Polyhedral Oligomeric Silsesquioxane Nanocomposites

“…Polyhedral oligomeric silsesquioxanes (POSS) moieties have the empirical formula (RSiO 1.5 ) n , where R may be an organic functional group (e.g., alkyl, alkylene, epoxide unit, acrylate, hydroxyl) or a hydrogen atom, controlled porosity and nanometer sized structure; the structures of POSS NPs can be divided into partial cage, ladder, and random structures [5,6,7,8,9]. The properties of POSS-containing polymers can improve (e.g., decreased flammability, viscosity, and heat discharge, and increased rigidity, strength, and modulus) via the degree of dispersion of the POSS NPs into the polymer matrix [10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26]. Two general approaches have been used to incorporate POSS units into polymer matrices: (i) physical blending [27,28,29,30] and (ii) covalent attachment [29,30,31,32,33,34,35].…”