Preparation and characterization of polyurethane/POSS hybrid aqueous dispersions from mono-amino substituted POSS

Raftopoulos

2017

J Therm Anal Calorim

Organic-inorganic hybrid materials, prepared via chemical synthesis route or physical blending of functionalized nanofillers within polymer matrix, have gained an increased attention in the recent years. Polyhedral oligomeric silsesquioxane (POSS) nanoparticles, due to their nanometer size and functionalization possibilities, are applied as effective modifiersboth chemical and physical, for polymer matrices, including polyurethanes (PU). In this work, we describe the synthesis and processing of polyurethane/POSS hybrid nanocomposites and discuss the influence of POSS moieties on the thermal properties of PU matrices. Glass transition, the crystallinity of the soft phase, as well as the order-disorder transitions are affected by the incorporation of POSS in the polyurethane structure. Direct polymer-POSS interaction, or -indirect-due to the suppression or enhancement of microphase separation by the POSS moieties are discussed in terms of topology of the polymeric structure with the key role of POSS functionalization.

Section: Polyurethane/poss Nanocompositessynthesis and Processingmentioning

confidence: 99%

The influence of POSS nanoparticles on selected thermal properties of polyurethane-based hybrids

Raftopoulos

2017

J Therm Anal Calorim

J of Applied Polymer Sci

“…And its active functional groups can improve the compatibility of the POSS with other matrix. Therefore it can be applied in polymers and improve its flame retardancy and smoke suppression 20,21 . Qu et al 22 modified graphene oxide with octa (propyl glycidyl ether) POSS and introduced it into epoxy resin (EP), and found that octa (propyl glycidyl ether) POSS could improve the dispersion of graphene oxide and enhance the flame retardancy of EP.…”

Section: Introductionmentioning

confidence: 99%

Flame retardancy of carboxylated polyhedral oligosilsesquioxane modified layered double hydroxide in the process of leather fatliquoring

Lyu

Kou

Gao

et al. 2022

Carboxyl polyhedral oligomeric silsesquioxane(P[POSS‐MAA]) modified layered double hydroxides (LDHs) (P[POSS‐MAA]‐LDHs) was prepared by exfoliating and recombination method, which used P(POSS‐MAA) and LDHs attracted each other through electrostatic force and hydrogen bond. The structure and morphology of P(POSS‐MAA)‐LDHs were characterized by X‐ray diffraction and transmission electron microscope, which showed that LDHs was exfoliated and P(POSS‐MAA) was on the surface of LDHs. Then it was introduced into the modified zanthoxylum bungeanum seed oil(MZBMSO) to obtain MZBMSO/P(POSS‐MAA)‐LDHs and applied it in leather fatliquoring process. The effect of the introduction of P(POSS‐MAA)‐LDHs on the flame retardancy, thermal stability, thermal insulation and smoke suppression of leather was investigated. Compared to the MZBMSO treated leather, the after flame time of MZBMSO/P(POSS‐MAA)‐LDHs treated leather decreased from 84 s to 32 s, and the limiting oxygen index increased from 23.1% to 27.5%, which exhibited improvement on flame retardancy of the leather. The temperature at 50% mass loss of MZBMSO/P(POSS‐MAA)‐LDHs treated leather increased from 375.1 to 408.3°C, which showed improvement on thermal stability of the leather. And the leather treated by MZBMSO/P(POSS‐MAA)‐LDHs had reduction of the total heat release and the total smoke production around 26.8% and 65.7%, respectively, which showed that MZBMSO/P(POSS‐MAA)‐LDHs treated leather had heat insulation and smoke suppression. Flame retardant mechanism of MZBMSO/(P(POSS‐MAA)‐LDHs) treated leather involved a combination of the gaseous phase and condensed phase flame retardancy. This work provided a new material for the flame retardant field and expanded the application range of polyhedral oligomeric silsesquioxane(POSS).

“…In spite of the large attention paid to the effects induced by the presence of polyhedral oligomeric silsesquioxanes (POSSs), their stabilization activities were scarcely investigated. The influence of structured polymer materials [ 17 , 18 , 19 ], hybrid composition [ 20 , 21 , 22 ], preparation conditions [ 23 , 24 ] are the main directions that are envisaged by the majority of assays. Unfortunately, the contribution of POSS filler to the delay of oxidation in polymer materials was randomly reported [ 25 , 26 ].…”

Section: Introductionmentioning

confidence: 99%

Stabilization Effects of Natural Compounds and Polyhedral Oligomeric Silsesquioxane Nanoparticles on the Accelerated Degradation of Ethylene-Propylene-Diene Monomer

Zaharescu¹,

Blanco

2021

Molecules

In this work the analysis on the stabilization activities of some natural antioxidants (rosemary extract, capsaicin, quercetin or oleanolic acid) is presented. A similar contribution of an inorganic structure—polyhedral oligomeric silsesquioxane (POSS) nanoparticles—is also evaluated. The stabilization effects on the oxidation protection were investigated for several formulations based on ethylene-propylene-diene-terpolymer (EPDM). The samples were examined in pristine state or after γ-irradiation, when the accelerated degradation scission of polymer macromolecules followed by the mitigation of oxidation. Three evaluation procedures: chemiluminescence, FTIR spectroscopy and thermal analysis were applied for the characterization of stability efficiency. The delaying effect of oxidative aging in EPDM matrix is illustrated by the values of activation energy, which are correlated with the type and concentration of embedded compounds. The durability of studied EPDM formulations is discussed for the assessment of material life. The improved behavior of structured hybrids useful for the optimization application regimes is essentially based on the antioxidant properties of polyphenolic components in the cases of natural antioxidants or on the penetration of free radical intermediates into the free volumes of POSS.