High-Energy Radiation-Induced Changes in the Crystal Morphology of Cellulose

2004 ◽  
Vol 37 (7) ◽  
pp. 2668-2670 ◽  
Author(s):  
Frederick G. Morin ◽  
Byron D. Jordan ◽  
Robert H. Marchessault
Keyword(s):  
Crystal Morphology ◽  
High Energy ◽  
High Energy Radiation ◽  
Energy Radiation ◽  
Radiation Induced ◽  
Induced Changes

High energy radiation induced degradation of reactive yellow 145 dye: A mechanistic study

2020 ◽  
Vol 177 ◽  
pp. 109115
Author(s):  
Majid Muneer ◽  
Muhammad Imran Kanjal ◽  
Muhammad Saeed ◽  
Tariq Javed ◽  
Atta Ul Haq ◽  
...  
Keyword(s):  
High Energy ◽  
Mechanistic Study ◽  
High Energy Radiation ◽  
Energy Radiation ◽  
Radiation Induced

Radiation-induced changes in the structure of polypropylene

1959 ◽  
Vol 253 (1274) ◽  
pp. 322-330 ◽  
Keyword(s):  
Main Chain ◽  
High Energy ◽  
Theoretical Expression ◽  
Cross Linking ◽  
Gel Point ◽  
High Energy Radiation ◽  
Infra Red ◽  
Radiation Induced ◽  
Induced Changes ◽  
Good Agreement

Polypropylene undergoes both cross-linking and random main-chain fracture when exposed to high-energy radiation, the ratio of cross-linking to chain fracture varying with the dose received up to the gel point. An examination of the infra-red absorption spectrum of the irradiated polymer has shown that, in addition, vinylidine unsaturation ( R . R' /C=CH 2 ) is formed in the ratio of one vinylidene double bond to each chain fracture. The rate of main-chain fracture deduced from intrinsic viscosity measurements has been found to be initially (up to a dose of 35 Mrad) a function of the number of chain fractures produced, rather than proportional to the intensity of the radiation, as might have been expected from the behaviour of other polymers. After a dose of 50 to 60 Mrad an insoluble cross-linked gel can be separated from the polymer by solvent extraction, and the sol fraction decreases on further irradiation in accordance with the theoretical expression derived by Charlesby (1953), assuming that for every cross-link formed, one bond between two monomer units is broken. A mechanism for the radiation-induced changes is proposed, based upon the application of classical chemical kinetics, which is in good agreement with the observed phenomena.

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