Post-radiation grafting of styrene to polyethylene film and distribution of grafted polystyrene

Shevlyakova, N. V.; D’yakova, M. G.; Luzina, N.N.; Semenov, V. I.; Shifrina, R.R.; Тверской, В. А.; Праведников, А.Н.

doi:10.1016/0032-3950(87)90345-5

Cited by 2 publications

(3 citation statements)

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“…The content of each of these types of active polymerization centers in the polymer depends on the irradiation dose and dose rate, temperature and oxygen concentration during the irradiation and storage of the polymer, its degree of crystallinity, thickness, and other factors. Studies [ 6 ] of the EPR spectra of 20 µm-thick PE films irradiated by an electron beam to a dose of 50 kGy showed that peroxide radicals are mainly present in such thin samples, and the appearance and shape of these spectra [ 7 ] are virtually the same for all irradiation doses. One hour after irradiation, the concentration of trapped peroxyradicals in the film is 0.4 × 10 19 spin/g and changes little thereafter.…”

Section: Resultsmentioning

confidence: 99%

“…Radiation graft polymerization allows the introduction of functional groups into polymers of various kinds by the direct graft polymerization of monomers, such as acrylic acid [ 1 , 5 ], vinylpyridines [ 6 , 7 ], acrylonitrile and others [ 8 ], or by the subsequent chemical modification of graft polymers [ 5 , 9 , 10 ]. The latter include PS, the chemical modification of which allows the introduction of a wide range of functional groups into its structure.…”

Section: Introductionmentioning

confidence: 99%

“…However, currently, the studies on influence of graft polymerization parameters on the distribution of graft PS over the cross section of the polymer matrix on PE films of different thicknesses irradiated in air are almost absent. Previously, such studies were carried out only for thin (up to 20 μm) PE films [ 6 , 17 ]. This information is of fundamental importance in the development of technology for the manufacture of asymmetric hybrid membranes for gas separation, namely, when choosing a mathematical model of hybrid membranes.…”

Section: Introductionmentioning

confidence: 99%

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Mechanism of Post-Radiation-Chemical Graft Polymerization of Styrene in Polyethylene

et al. 2021

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Structural and morphological features of graft polystyrene (PS) and polyethylene (PE) copolymers produced by post-radiation chemical polymerization have been investigated by methods of X-ray microanalysis, electron microscopy, DSC and wetting angles measurement. The studied samples differed in the degree of graft, iron(II) sulphate content, sizes of PE films and distribution of graft polymer over the polyolefin cross section. It is shown that in all cases sample surfaces are enriched with PS. As the content of graft PS increases, its concentration increases both in the volume and on the surface of the samples. The distinctive feature of the post-radiation graft polymerization is the stepped curves of graft polymer distribution along the matrix cross section. A probable reason for such evolution of the distribution profiles is related to both the distribution of peroxide groups throughout the sample thickness and to the change in the monomer and iron(II) salt diffusion coefficients in the graft polyolefin layer. According to the results of electron microscope investigations and copolymer wettability during graft polymerization, a heterogeneous system is formed both in the sample volume and in the surface layer. It is shown that the melting point, glass transition temperature and degree of crystallinity of the copolymer decreases with the increasing proportion of graft PS. It is suggested that during graft polymerization a process of PE crystallite decomposition (melting) and enrichment of the amorphous phase of graft polymer by fragments of PE macromolecules occurs spontaneously. The driving force of this process is the osmotic pressure exerted by the phase network of crystallites on the growing phase of the graft PS.

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Section: Resultsmentioning

confidence: 99%