Morphology and mechanical properties of high density polyethylene-POSS hybrid nanocomposites obtained by reactive blending

Morphology, Mechanical Properties and Shape Memory Effects of Polyamide12/Polyolefin Elastomer Blends Compatibilized by Glycidylisobutyl POSS

Small amounts of glycidylisobutyl polyhedral oligomericsilsesquioxane (G-POSS) (up to 10 phr) were added into a immiscible polyamide12 (PA12)/polyolefin elastomer (POE) blend (70 wt%/30 wt%) by simple melt mixing. The effects of the G-POSS on phase morphology and mechanical properties were investigated by FE-SEM, tensile testing, Izod impact test and dynamic mechanical analysis. FE-SEM analysis revealed that domain size of the dispersed POE phase in matrix PA12 is decreased significantly by adding the G-POSS, indicating a compatibilization effect of the G-POSS for the immiscible PA12/POE blend. The PA12/POE blend compatibilized with POSS showed simultaneous enhancement in mechanical properties including tensile modulus, strength and toughness. Further, thermally triggered shape memory effect was observed in this compatibilized blend.

Silsesquioxane Derivatives as Functional Additives for Preparation of Polyethylene-Based Composites: A Case of Trisilanol Melt-Condensation

In this work, polyethylene (PE) composites were prepared with a series of completely condensed silsesquioxanes (SSQ), as well as with open-cage hepta(isobutyl)trisilanol silsesquioxane. The effect of the additives on the thermal, mechanical, rheological, and crystalline properties of the composites obtained was determined. The dispersion of trisilanol derivative within polymer matrix was slightly better than that of the other isobutyl compounds, suggesting condensation of the additive to less polar products of different structure, which was confirmed by thermogravimetry (TG) and matrix-assisted laser desorption-ionization time-of-flight (MALDI-TOF) mass spectrometry analysis. The additives improved the thermal stability of polyethylene and formed composites of higher rigidity than the neat polyolefin. The results were compared to the literature data, with aminopropylhepta(isobutyl)silsesquioxane and vinylhepta(isobutyl)silsesquioxane being used partially as references, as PE composites thereof were reported earlier, but lacked some analytical results and required further investigation. It was proven that the practical upper loading limit for such silsesquioxane compounds as processing and functional additives for polyethylene should be fixed at around 1%.

Polyethylene telechelics with POSS termini: synthesis, morphologies and shape memory properties

Organic–inorganic polyethylene (PE) telechelics with polyhedral oligomeric silsesquioxane termini were synthesized via the combination of acyclic diene metathesis, ring-opening metathesis polymerization and hydrogenation reactions.

An insight into the amphiphobicity and thermal degradation behavior of PDMS-based block copolymers bearing POSS and fluorinated units

Methacryloxypropyl-polyhedral oligomeric silsesquioxane (MAPOSS) and dodecafluoroheptyl methacrylate (DFHM) are proposed to separately block-copolymerize with polydimethylsiloxane (PDMS)-based acrylate block copolymer (PDMS-b-PMMA). The syntheses of PDMS-b-PMMA-b-PMAPOSS and PDMS-b-PMMA-b-PDFHM were executed in this manner to examine the effect of PMAPOSS and PDFHM on surface amphiphobic behavior and thermal degradation behavior. PMAPOSS and PDFHM were found to both contribute towards the improvement of static hydrophobicity. However, the PMAPOSS was found to disable the dynamic hexadecane-dewetting properties because of its restriction on molecular wriggling motion and its induced high roughness. In contrast, PDFHM was found to improve the dynamic dewetting properties for oil-based ink. With regard to the thermal stability, the incorporation of either PMAPOSS or PDFHM into PDMS-b-PMMA with PDMS (Mn ∼1000 or 5000 Da) favors the increase in the original thermal-decomposition temperature. However, the presence of PMAPOSS initiates a higher degradation rate and fails to improve the thermal stability in the case of long PDMS (Mn ∼10 000 Da) due to the heterogeneous dispersion of POSS in the matrix.

Preparation and characterization of a PVDF/EG-POSS hybrid ultrafiltration membrane for anti-fouling improvement

The octa vinyl silsesquioxane (OvPOSS) was used to synthesis POSS grafted ethylene glycol (EG) (EG-POSS). The hydrophilicity and anitifouling property of pure PVDF membrane was improved by incorporating EG-POSS in PVDF membrane.