Crosslinking in metallocene ethylene-co-5,7-dimethylocta-1,6-diene copolymers initiated by electron-beam irradiation

Abstract

The synthesis of ethylene-co-5,7-dimethylocta-1,6-diene copolymers (CEDMO) with different molar DMO contents has been performed to incorporate double bonds in the lateral and make easier the development of crosslinkings in the resulting polymer material after application of electron-beam irradiation. The gel content as well as a comprehensive evaluation of the changes in the crystalline characteristics have been carried out. Both features are strongly dependent on DMO composition and irradiation doses. Variation in the mechanical response of the different specimens has been checked by microhardness measurements.

Metallocene ethylene‐co‐(5,7‐dimethylocta‐1, 6‐diene) copolymers crosslinked using electron beam irradiation: a tunable alternative

“…The gel content estimated in the irradiated samples is strongly dependent on the DMO content and irradiation dose, as depicted in Fig. 1 and as previously reported 11. This gel is related to the network structure developed in the amorphous regions, which is insoluble in the solvent, whereas the sol content corresponds to the linear portion of the polymer in both amorphous and crystalline regions.…”

“…Copolymerizations of ethylene and DMO were performed as described elsewhere11, 16 and several CEDMO copolymers, with various comonomer contents, were obtained. They were labelled as CEDMO followed by two numbers that indicate their molar composition in terms of DMO.…”

“…Some other protocols2 are less frequently used or have only been investigated in the laboratory, and they are, among others, high‐frequency heating, initiation by thermal decomposition of azo‐esters or ethers, UV irradiation, redox initiation and free radical‐initiated grafting of various moieties onto polyalkene chains. A recent investigation was focused on a different strategy based on the preparation of unsaturated polyolefins through the copolymerization of ethylene with non‐conjugated dienes and their further electron beam irradiation 11. This route takes advantage of the use of metallocene catalysts12–15 leading to the synthesis of copolymers with narrow molecular weight distributions and with the side branches randomly distributed along the polymer backbone.…”

“…A previous report on irradiated CEDMO copolymers11 was primarily focused on an evaluation of different crystalline features shown by the distinct as‐processed irradiated copolymers depending on composition and dose. Then, knowledge of crystal lattice constants (from wide‐angle X‐ray scattering (WAXS) measurements) and of crystallite size (from small‐angle X‐ray scattering (SAXS) measurements) was obtained using real‐time variable‐temperature experiments employing synchrotron radiation.…”

Study of the effect of gamma irradiation on a commercial polycyclooctene I. Thermal and mechanical properties

“…Most of the polymers undergo crosslinking reaction upon exposure to radiation, like electron beam (Cerrada et al, 2009; or gamma radiation (Abdel-Aziz and Basfar, 2000;Barkhudaryan, 2000b;Shyichuk et al, 2001). Thus, different authors have studied the involved crosslinking mechanism (Kurtz et al, 1999;Premnath et Radiation Physics and Chemistry 102 (2014) 108-116 al., 1996;Tamboli et al, 2004).…”