Radiation and industrial polymers

Bhattacharya, Amit

doi:10.1016/s0079-6700(00)00009-5

Cited by 316 publications

(186 citation statements)

References 117 publications

Supporting

Mentioning

161

Contrasting

Unclassified

Order By: Relevance

“…[50] Random chain scission (in the main chain) leads to a reduction of molecular weight and hence the deterioration of mechanical stability, including the formation of cracks on the surface and finally the embrittlement of the surface. [51] The latter may be increased by UV-induced crosslinking on the surface, also as the resulting increased density on the surface leads to mechanical tension with unaffected lower-density material deeper below the surface.…”

Section: Colour Measurementsmentioning

confidence: 99%

Contaminant release from aged microplastic

et al. 2017

View full text Add to dashboard Cite

Environmental context. Increasing global plastic production adds plastic debris to the environment. We show that potentially harmful additives present in plastic particles are released to water at an increased rate when material properties change by aging due to exposure to high temperature and especially to UV radiation. For risk assessment of such plastic additives, more information on their degradation products and their toxicity is needed.Abstract. Recycled plastic granules of high-density polyethylene, polyvinyl chloride and polystyrene the size of microplastics were exposed to artificial aging conditions (2000 h; photooxidative and thermo-oxidative) to simulate their fate outdoors. Their potential to leach into water during the aging process was investigated using column percolation tests. Aging-related changes on the surface of the material were characterised by IR measurements indicating oxidation reactions with the formation of new adsorption bands (C=O, C-O and OH), especially in the case of photooxidative aging. These findings were confirmed by the identification of leachable organic compounds. Leaching of total organic carbon, Cl, Ca, Cu and Zn is clearly affected by changes due to aging, and their release is increased after photooxidative aging. In general, exposure to photooxidative conditions shows a greater influence on aging and thus on leaching and seems to be the more important mechanism for the aging of microplastic in the environment. Comparison with the total content of inorganic species revealed that, for most elements, less than 3% of the total content is released after 2000 h of photooxidative aging.

show abstract

Section: Colour Measurementsmentioning

confidence: 99%

Contaminant release from aged microplastic

et al. 2017

View full text Add to dashboard Cite

show abstract

“…The free radicals or molecular ions can react by connecting the polymer chains directly or by initiating grafting reactions [16]. The chemistry of the process is based on macroradical formation from elastomer chains, which recombine causing structuring [17,18].…”

Section: Resultsmentioning

confidence: 99%

“…Radicalii liberi sau ionii moleculari pot reacþiona prin legarea directã de lanþul polimeric sau prin iniþierea reacþiilor de grefare [16]. Chimia procesului se bazeazã pe formarea de macroradicali pe lanþul elastomeric, care se recombinã determinând structura finalã [17,18].…”

Section: Resultsunclassified

The Crosslink Density of Ethylene-Vinyl-Acetate Copolymer/Triallylcyanurate Mixture Cross-linked by Electron Processing

Stelescu¹,

Mănăilă²,

Crăciun³

et al. 2014

LFJ

View full text Add to dashboard Cite

ABSTRACT. Vulcanization by electron beam (EB) irradiation involves the interaction of electron energy and an elastomer. The interaction results in formation of free radicals by dissociation of molecules in the excited state or by interaction of molecular ions. The free radicals or molecular ions can react by connecting directly to the polymer chains or by initiating grafting reactions. The chemistry of the process is based on macroradical formation from elastomer chains, which recombine causing structuring. This paper presents the effect of ionizing radiation on mixtures based on ethylene-vinyl acetate copolymer (EVA) and triallylcyanurate (TAC). Samples were subjected to electron beam treatment with doses ranging between 50 kGy and 500 kGy. The induced crosslinking of EVA/TAC samples was evaluated with gel fraction (crosslinked polymer content) and crosslink density determination. The cross-linking density of the samples was determined on the basis of equilibrium solvent-swelling measurements (in toluene at 23-25°C) by applying the well-known modified Flory-Rehner equation for tetra functional networks, where values of the solubility parameter were calculated according to Small, Hoy and Krevelen. Sol-gel analyses and crosslink density have shown that samples tend to cross-link as a result of electron beam irradiation. As EB dose increases, there is an increase of gel fraction, of volume fractions of polymer in the samples at equilibrium swelling (í2m) and of cross-link density (í), and a decrease of swelling ratio G (toluene soluble polymer quantity). The highest value of crosslinking rate was obtained for the sample irradiated with a dose of 350 kGy. KEY WORDS: ethylene-vinyl-acetate-copolymer, triallylcyanurate, cross-linking, electron beam DENSITATEA DE RETICULARE A UNOR AMESTECURI COPOLIMER ETILEN-VINIL-ACETAT/TRIALILCIANURAT RETICULATE PRIN PROCESAREA CU ELECTRONIACCELERAÞI REZUMAT. Vulcanizarea prin iradiere cu electroni acceleraþi (EA) se bazeazã pe interacþiunea dintre energia electronilor ºi elastomerul supus acestui tratament. În urma acestei interacþiuni se obþin radicali liberi formaþi prin disocierea moleculelor aflate în stare excitatã sau prin interacþiunea ionilor moleculari. Radicalii liberi sau ionii moleculari pot reacþiona prin legarea directã de lanþul polimeric sau prin iniþierea reacþiilor de grefare. Chimia procesului se bazeazã pe formarea de macroradicali pe lanþul elastomeric, care se recombinã determinând structura finalã. În aceastã lucrare este prezentat efectul radiaþiei ionizante asupra unor amestecuri pe bazã de copolimer etilen-vinil-acetat (EVA) ºi trialilcianurat (TAC). Probele au fost supuse tratamentului cu electroni acceleraþi cu doze cuprinse între 50 kGy ºi 500 kGy. Reticularea prin iradiere a probelor EVA/TAC a fost evaluatã prin determinarea fracþiei de gel ºi a densitãþii de reticulare. Densitatea de reticulare a probelor a fost determinatã pe baza mãsurãtorilor gradului de gonflare în solvent (toluen) la 23-25°C, prin aplicarea bine cunoscutei ecuaþii modificate Flor...

show abstract

“…Along chain courses of polymers CR-39, act particularly as opposed to other comprehended materials and claim wonderful properties in view of that are comprehensively used as a piece of various sensible and mechanical applications [1][2][3][4][5][6][7]. It is striking that molecule society adjusts the polymer frame work by chain scission, crossinterfacing, free radical alternative, protruding holding pair [6,7].…”

Section: Introductionmentioning

confidence: 99%