The effects of structure of POSS on the properties of POSS/PMMA hybrid materials

Abstract

Octa‐vinyl polyhedral oligomeric silsesquioxane (V‐POSS) and octa‐(methacryloxy) propyl polyhedral oligomeric silsesquioxane (M‐POSS) were incorporated into PMMA to prepare POSS/PMMA hybrid materials at molecular level via in situ polymerization. The resulting hybrid materials showed only swelling instead of solution in ethyl acetate, while pristine PMMA completely dissolved in ethyl acetate; moreover, the M‐POSS/PMMA hybrid materials exhibited more excellent resistance to solvent stress cracking. An excellent transparency was observed for all hybrid materials. Incorporation of V‐POSS and M‐POSS significantly improved thermal properties of PMMA. The thermal decomposition temperature of hybrid materials was enhanced except a slightly compromised initial decomposition temperature. The hybrid materials prepared with 0.2–0.6 mol% M‐POSS or V‐POSS improved the reinforcing and toughening properties in comparison to pristine PMMA. Also, the incorporation of POSS decreased the dielectric constant and dielectric loss of the hybrid materials with more voids introduced into the composites no matter the structure of POSS. POLYM. ENG. SCI., 55:565–572, 2015. © 2014 Society of Plastics Engineers

Bioactivity and properties of a dental adhesive functionalized with polyhedral oligomeric silsesquioxanes (POSS) and bioactive glass

“…At low concentrations, POSS particles were successfully incorporated into experimental composite decreasing the volumetric shrinkage and improving the mechanical properties, e.g. flexural strength, Young`s modulus or hardness [13][14][15][16]. When applied in a dental adhesive, the fillers acting as a cross-link agent may also enhance the bond to a composite through the increase of the shear strength [17].…”

Development of Cycloaliphatic Epoxy-POSS Nanocomposite Matrices with Enhanced Resistance to Atomic Oxygen

“…Initially, the stiffest of the matrices is the unmodified base epoxy and, at low concentrations of 5%, the addition of the POSS nanofiller results in an increase in the flexural modulus of the specimens followed by a decrease in this property as the POSS concentration is further increased; this is true for both the E 11 and E 22 values. The POSS cages have a higher modulus than the polymer chains and these rigid structures can form bonds with the organic molecular chains of the epoxy resin matrix and restrict their movement, thus improving their flexural properties [35]. It is important, however, to note that the magnitude of the increase in the average tangent modulus of the samples is within the expected error associated with the test.…”

Poly(methyl methacrylate) hybrid syntactic foams with hollow glass microspheres and polyhedral oligomeric silsesquioxanes

“…There have been several studies on PMMA-POSS composites in which thermal and mechanical properties of PMMA were enhanced. [37][38][39][40][41][42] POSS particles can also improve properties such as flame retardancy and thermal stability of polymers depending on the functional groups around the silica cage. 43 The addition of octa(3-chloropropyl) POSS and trisilanolphenyl POSS improved the thermal stability of PMMA.…”