Preparation and properties of transparent PMMA/ZrO2 nanocomposites using 2-hydroxyethyl methacrylate as a coupling agent

P(VDF-TrFE)/ZrO2 Polymer-Composites for X-ray Shielding

“…These overlapped absorption bands are attributed to the sum of the p -p* transitions of PMMA absorption band, which starts around 270nm and attains its maximum at 226 nm, and the ZrO 2 absorption band, which starts around 400 nm and attains its maximum at 270 nm, as one can be inferred from Fig 2(b). These UV absorption bands have also been observed by Hu et al, 16 in a very interesting work about properties of transparent PMMA/ZrO 2 composites, with 0.8, 5 and 7 wt% of ZrO 2 , made by in-situ polymerization of MMA/ZrO 2 dispersion. Actually, as it was not possible to produce pure MMA/ZrO 2 composites in our work, because of the methodology used, we have attributed the absorption band at 270 nm to ZrO 2 based on information provided in that reference.…”

“…However, this intense absorbance band is reported to be present in the PMMA/ZrO 2 nanocomposites made by different methods, for all ZrO 2 concentrations studied. 10,13,16 It is also present in P(VDF-TrFE)/PMMA blends, for all PMMA contents, but downshifted to 1735 cm -1 . 17 Although a conclusive explanation to this phenomenon requires additional investigations and calculation by molecular modeling, we suggest that the absorption band at 1645 cm -1 could be originated by the weakening of the C=O bond, which could also be sharing its electronic charge with the P(VDF-TrFE) copolymer chain, decreasing its intensity at 1745 cm -1 .…”

“…The band at 1450 cm -1 is attributed to sum of the scissors vibration of CH 2 and the antisymetric deformation of CH 3 molecules in MMA. 16 The high absorption seen at 1555 cm -1 is attributed to the stretching of Zr-O bonds whereas the bands at 1645 and 1705 cm -1 may be attributed to the stretch of C=O bonds in MMA.…”

“…14 Also, in this respect, we note that the FTIR data collected at higher temperatures for PMMA/ZrO 2 nanocomposites reported in the literature have clearly demonstrated the absence of these absorption bands above 100°C. 10,16 DSC thermograms were collected in order to detect changes in the P(VDF-TrFE) 50/50 crystalline structure provoked by the addition of ZrO 2 -MMA nanoparticles. This DSC data could be of great help in view of well known ferroelectric behavior of P(VDF-TrFE) that presents a ferroelectric-to-paelectric (f-p) phase transition for trifluorethylene contents ranging from 18 to 63 mol%.…”

Morphology, mechanical properties and thermal degradation kinetics of PMMA-zirconia nanocomposites prepared by melt compounding

“…FTIR, TEM and UV investigations showed that zirconia nanoparticles were generally homogeneously dispersed in the polymer matrix at primary particle size level and that the composites were transparent [6][7][8][9][10][11][12]. TGA analyses of PMMA-ZrO 2 nanocomposites in air and nitrogen atmospheres, where a sol-gel method was used for the preparation of the nanocomposites, showed three degradation steps with the thermal stability increasing in the presence of zirconia [10,11]. However, the onset temperatures of the second step in nitrogen and of the third step in air of the nanocomposites were lower.…”