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291.
292.
Fernando Rull Jorge Rodriguez Jose María Alia Fernando Arroyo Howell Edwards 《Macromolecular Symposia》1995,94(1):189-200
FT-Raman spectroscopic studies of photodegraded polyethylene films have enabled the evolution of the crystallinity process to be measured. Commercial polyethylene films of Mw=90 000 were exposed in a weathering UV-chamber under known conditions of exposure time and radiant energy. The spectral profiles were modelled using Fourier methods. The relative amounts of the orthorrombic crystalline phase, αc, the amorphous phase, αa and the interphase, αb, were calculated using Raman bands at 1416 cm−1 characteristic of the crystalline phase and the bands at 1080, 1305 cm−1, characteristic of the amorphous phase. The interphase content can be calculated from the relationship αb= 1-(αc+αa). It was found that the weathering process affects only the relative intensities of the bands attributed to crystalline and amorphous fractions; the crystalline content increases at the expenses of the amorphous fraction. These results are discussed in terms of the changes in the intermolecular forces caused by radiation exposure. 相似文献
293.
294.
Bernab L. Rivas S. Amalia Pooley Maribel Luna 《Macromolecular rapid communications》2001,22(6):418-421
The synthesis and characterization of the water‐soluble poly(N‐acetyl‐α‐acrylic acid) by radical polymerization were carried out. The polymer was characterized by Fourier Transform Infrared (FT‐IR), 1H NMR and 13C NMR spectroscopies, and thermogravimetric analysis (TGA). The metal ion binding properties for the metals Cu(II), Co(II), Ni(II), Cd(II), Zn(II), Pb(II), Hg(II), Cr(III) in the aqueous phase were studied using the liquid‐phase polymer‐based retention technique. The metal ion interactions with the hydrophilic polymer were determined as a function of pH and of the filtration factor. The polychelatogen showed a high affinity for metal ions and higher selectivity for Cr(III) at pH = 3. 相似文献
295.
Bernab L. Rivas S. Amalia Pooley Maribel Luna 《Macromolecular rapid communications》2000,21(13):905-908
The synthesis of poly(N‐acryloylpiperazine) was carried out by radical polymerization giving a yield of 90%. The polymer was soluble in water and was characterized by FTIR, 1H NMR, 13C NMR spectroscopy, and TGA. The metal ability binding properties for the Ag(I), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Pb(II), and Cr(III) metal ions in the aqueous phase were investigated using the liquid‐phase polymer‐based retention (LPR) method. The metal ion interactions with the hydrophilic polymers were determined as a function of pH and filtration factor. 相似文献