Degradation by Electron Beam Irradiation of Some Elastomeric Composites Sulphur Vulcanized

Elena Manaila; Gabriela Craciun; Ion Bogdan Lungu; Marius Daniel Dumitru Grivei; Maria Daniela Stelescu

doi:10.3390/ma16062152

Degradation by Electron Beam Irradiation of Some Elastomeric Composites Sulphur Vulcanized

Materials (Basel). 2023 Mar 7;16(6):2152. doi: 10.3390/ma16062152.

Authors

Elena Manaila¹, Gabriela Craciun¹, Ion Bogdan Lungu², Marius Daniel Dumitru Grivei¹, Maria Daniela Stelescu³

Affiliations

¹ Electron Accelerators Laboratory, National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor St., 077125 Magurele, Romania.
² Multipurpose Irradiation Facility Center-IRASM, Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering, 30 Reactorului St., 077125 Magurele, Romania.
³ National R&D Institute for Textile and Leather-Leather and Footwear Research Institute, 93 Ion Minulescu St., 031215 Bucharest, Romania.

Abstract

Composites based on natural rubber and plasticized starch obtained by the conventional method of sulfur cross-linking using four types of vulcanization accelerators (Diphenyl guanidine, 2-Mercaptobenzothiazole, N-Cyclohexyl-2-benzothiazole sulfenamide, and Tetramethylthiuram disulfide) were irradiated with an electron beam in the dose range of 150 and 450 kGy for the purpose of degradation. The vulcanization accelerators were used in different percentages and combinations, resulting in four mixtures with different potential during the cross-linking process (synergistic, activator, or additive). The resulting composites were investigated before and after irradiation in order to establish a connection between the type of accelerator mixture, irradiation dose, and composite properties (gel fraction, cross-linking degree, water absorption, mass loss in water and toluene, mechanical properties, and structural and morphological properties). The results showed that the mixtures became sensitive at the irradiation dose of 300 kGy and at the irradiation dose of 450 kGy, and the consequences of the degradation processes were discussed.

Keywords: composites; degradation; electron beam; irradiation; natural rubber; plasticized starch; vulcanization accelerators.

Grants and funding

This research was supported by the Romanian Ministry of Research, Innovation and Digitalization under the Romanian National Core Program LAPLAS VII (NUCLEU)—contract no. 30N/2023.