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

Abstract

Hybrid organic-inorganic polymer nanocomposites incorporating polyhedral oligomeric silsesquioxane (POSS) nanoparticles are of increasing interest for high performance materials applications. Octaisobutyl POSS/polypropylene nanocomposites were prepared at varying POSS concentrations via melt blending. The interplay of POSS molecular geometry, composition, and concentration in relation to the tribological, nanomechanical, surface energy, and bulk properties of the nanocomposites were investigated. Ultra-low friction and enhanced hardness, modulus, and hydrophobicity were observed for the nanocomposite surfaces, with minimal changes in the bulk thermomechanical properties. Parallel AFM, SEM, TEM, and spectroscopic analyses demonstrated significant differences in POSS distribution and aggregation in the surface and the bulk, with preferential segregation of POSS to the surface. Additionally, contact angle studies reveal significant reduction in surface energy and increase in hysteresis with incorporation of POSS nanoparticles. The differences in bulk and surface properties are largely explained by the gradient concentration of POSS in the polymer matrix, driven by POSS/POSS and POSS/polymer interactions.

Fouling release nanostructured coatings based on PDMS-polyurea segmented copolymers

“…Alternatively, large ∆θ values have been attributed to an energy dissipation mechanism associated with thermodynamically irreversible molecular rearrangements on the solid surface that follows wetting [45][46][47]. A12MPOSS has both the highest θ a and ∆θ values (140 and 110 o respectively), a behavior that has been previously reported for other POSS-containing hybrids [39].…”

“…The surface of the neat copolymer A12M is enriched with PDMS, as evidenced by the increased concentration of silicon and the reduced concentration of carbon (the stoichiometric ratio of carbon is higher for the hard segments (Figure 4) reveal extensive migration of the low surface energy POSS nanoparticles to the surface, where they form large aggregates [37][38][39]. Similarly, the SEM image of the A12M surface also shows extensive phase segregation.…”

Thermal Oxidation of Polyolefins by Mild Pro-Oxidant Additives Based on Iron Carboxylates and Lipophilic Amines: Degradability in the Absence of Light and Effect on the Adhesion to Paperboard

“…The organic groups allow POSS compounds to be easily incorporated into organic polymers [23,24]. POSS has recently been used in thermoplastics and improve several properties of the materials [25][26][27][28][29][30][31][32][33]. In our previous work, small amounts of bio-POSS octa-(ethyl octadeca 10,13-dienoamide silsesquioxanes) was added to polyethylene (PE) and laminated with paperboard.…”

Role of interface in dispersion and surface energetics of polymer nanocomposites containing hydrophilic POSS and layered silicates

“…Adding POSS to polymers can bring about significant improvements in the bulk properties of these polymers such as increased thermal stability, hardness, wear resistance, oxidative resistance, mechanical properties and decreased flammability and viscosity during processing [9][10][11][12][13][14][15][16][17][18][19][20]. There are also some limited studies on the surface hydrophobicity of POSS-based polymer nanocomposites [9,10,14,15,[18][19][20][21][22][23].…”