In situ polymerization of silicic acid in polyethylene–octene elastomer: Properties and characterization of the hybrid nanocomposites

Abstract

Silicic acid produced from sodium metasilicate hydrate and metallocene polyethylene-octene elastomer (POE) were chosen as the ceramic precursor and the continuous phase, respectively, for preparation of new hybrids by an in situ sol-gel process. To obtain a better hybrid, the acrylic acid-grafted polyethylene-octene elastomer (POE-g-AA) prepared in our laboratory and used as the continuous phase was also investigated. Characterizations of POE/SiO 2 and POE-g-AA/SiO 2 composites were performed by Fourier transform infrared spectroscopy, 29 Si solid-state nuclear magnetic resonance (NMR) spectrometry, X-ray diffractometry, differential scanning calorimetry, thermogravimetry analysis, and an Instron mechanical tester. The POE-g-AA/ SiO 2 hybrid could give the positive effect on the properties of POE/SiO 2 hybrid because the carboxylic acid groups of acrylic acid should act as coordination sites for the silica phase to form chemical bonds. The result of 29 Si solid-state NMR spectra showed that Si atom coordination around SiO 4 units is predominantly Q 3 and Q 4 . Also, the POE-g-AA/SiO 2 hybrid with 15 wt % SiO 2 gave the maximum values of tensile strength and glass-transition temperature because excess particles might cause the separation between the organic and inorganic phases when the silica content was beyond this point.

In situ polymerization of titanium isopropoxide in polycaprolactone: Properties and characterization of the hybrid nanocomposites

“…The glass transition temperature (T g ) of the hybrid composites is associated with a cooperative motion of long-chain segments, which may be hindered by the titania network. 7 Therefore, as expected, both PCL/ TiO 2 and PCL-g-AA/TiO 2 recorded higher glass tran- sition temperatures than pure PCL (Table III). It was also found that the enhancement in T g for PCL-g-AA/ TiO 2 hybrids was more significant than that for PCL/ TiO 2 hybrids.…”

“…This result may be due to the formation of ester groups through the reaction between carboxylic acid groups of PCL-g-AA and titanium-bonded isopropyl groups of the titania network. 7,32 Furthermore, a comparison of the PCL and PCL/ TiO 2 (10 wt %) spectra shows new peaks between 3000 and 3800 cm Ϫ1 (Fig. 1) and at 821 and 1622 cm Ϫ1 (Fig.…”

“…16,17 Titania is seldom used. Our previous studies 7 and the reports of Fitzgerald 18 have indicated that factors such as particle size of inorganic phase, uniform distribution of inorganic phase within the organic phase, and interfacial forces between the two phases significantly affect the microstructures and the properties of hybrid materials. Interfacial forces lead to the formation of either hydrogen bonds or covalent bonds between the two phases.…”

“…[1][2][3][4][5][6][7][8][9][10][11][12] The promise of these new hybrid materials is a controllable combination of the properties of the polymer (flexibility, toughness, and easy processing) and the ceramic/ glass (hardness, durability, and thermal stability). In synthesizing the organic-inorganic composite, the organic polymer is generally the dominant phase, modified by the inorganic phase.…”

Characterizing composite of multiwalled carbon nanotubes and POE‐g‐AA prepared via melting method

“…The peak at 2y ¼ 18.08 may be due to the formation of an ester carbonyl functional group, as described in the discussion of FTIR analysis, and is similar to that reported by Wu and Liao. 36 Condensation between POE-g-AA and MWNTs-COCl also caused the reappearance of a peak at 2y ¼ 19.88, which is due to recovery of POE characteristics with the consumption of AA in the POE-g-AA. Because the peaks at 2y ¼ 26.18 and 43.18 in the spectrum of MWNTs-COOH [ Fig.…”