POSS compounds as modifiers and additives for elastomeric composites

Abstract

Zwi¹zki POSS jako modyfikatory i dodatki do kompozytów elastomerowychStreszczenie -Zbadano mo¿liwooeae zastosowania silseskwioksanów (POSS) w charakterze na-pe³niaczy b¹dŸ modyfikuj¹cych dodatków do elastomerów: kauczuku metylowinylosilikonowego (MVQ) oraz uwodornionego butadienowo-akrylonitrylowego (HNBR). Stwierdzono, ¿e odpowiednio sfunkcjonalizowane silseskwioksany mog¹ braae udzia³ w sieciowaniu kauczuków, zwiêkszaae ich wytrzyma³ooeae mechaniczn¹, zw³aszcza w temp. -50 °C, ograniczaae dzia³anie czynników starzeniowych oraz korzystnie poprawiaae hydrofobowooeae powierzchni, wp³ywaj¹c jednoczeoenie na barierowooeae wobec tlenu. Dodatek do wulkanizatów kauczuków zwi¹zków POSS zawieraj¹cych kwasowe lub zasadowe ugrupowania pozwala na otrzymanie materia³ów obdarzonych zdolnooeci¹ do samonaprawy. S³owa kluczowe: kompozyty elastomerowe, silseskwioksany, kauczuk silikonowy, uwodorniony kauczuk butadienowo-akrylonitrylowy. POSS COMPOUNDS AS MODIFIERS AND ADDITIVES FOR ELASTOMERIC COMPOSITESSummary -The possibility of using silsesquioxanes (POSS) as nanofillers or modifying additives to elastomers: methylvinylsilicone (MVQ) and hydrogenated butadiene-acrylonitrile (HNBR) rubber was studied. It was found that suitably functionalized silsesquioxanes can take part in the cross-linking of rubbers and increase their mechanical strength, especially at temperature of -50 °C. They can also reduce the ageing effects and increase the surface hydrophobicity, while at the same time influencing oxygen barrier properties. The addition of POSS compounds containing acidic or basic groups to rubber vulcanizates enables the preparation of materials with self-healing properties.

Dual crosslinking of carboxylated nitrile butadiene rubber latex employing the thiol‐ene photoreaction

“…(1), where V P is the volume fraction of the polymer in the swollen state, V S the molar volume of the solvent, and χ the Flory‐Huggins interaction parameter. The Flory‐Huggins interaction parameter was calculated with the following equation, χ = 0.487 + 0.228 × V P in accordance to literature 25…”

Properties of Carboxylated Nitrile Rubber/Hydrotalcite Composites Containing Imidazolium Ionic Liquids

“…The Flory-Huggins interaction parameter was calculated with the Equation 2 in accordance to literature. [29,30] x ¼ 0:487 þ 0:228 Á V p ð2Þ…”

“…The value of the storage modulus (E') is reported in Table 3. Plots of the loss tangent (tan d), storage modulus (E') and loss modulus (E") versus temperature are illustrated in Figure 1a-c. From Figure 1a, we can observe that the XNBR/HT compounds present two relaxations: one at low temperatures, which corresponds to the glass transition (T g ) of the XNBR matrix, and another from 10 C to 50 C with a maximum at 30 C, corresponding to the ionic transition temperature (T i ), which indicates the existence of ionomeric clusters formed during the crosslinking of XNBR with HT. [31] These clusters melt at higher temperatures resulting in additional tan d peaks during the DMA analysis.…”

“…Where V p is the volume fraction of the polymer in the swollen gel, V S the molar volume of the solvent, and χ the Flory‐Huggins interaction parameter. The Flory‐Huggins interaction parameter was calculated with the Equation in accordance to literature …”

Effect of Polyhedral Oligomeric Silsesquioxanes Nanoparticles on Thermal and Mechanical Properties of Poly(vinyl chloride) Composite Materials

“…Polyhedral oligomeric silsesquioxanes (POSS) are novel hybrid materials that have three-dimensional inorganicorganic, structurally well-defined cage-like molecules and the sizes range from 1 to 3 nm, with the empirical formula RSiO 1.5 (where R may be a hydrogen atom or an organic functional group, for example, alkyl, alkylene, acrylate, hydroxyl, or epoxide unit). As a result of advantageous properties created by the possibility of incorporation of variety of reactive functional groups into their molecule, POSS have a wide range of applications, including modification of both thermoplastic and thermoset polymeric materials by chemical cross-linking or physical blending methods [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15].…”