FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W599716170> ?p ?o ?g. }

• W599716170 abstract "The radiation degradation of poly(amino acid)s, amino acid copolymers, N-acetylamino acids, ethylene-a-olefin copolymers, polyethylenes and reduced poly(vinyl chloride)s has been investigated.Homopolymers of amino acids with a variety of side-chains have been used as models to investigate the effect of molecular structure on the radiation sensitivity of polypeptides. In this study, (1) the volatile radiolysis products and their yields have been identified and measured by gas chromatography (GC) and gas chromatography/ mass spectrometry (GC/MS), (2) free radical intermediates and their yields at 25dC, at -196dC, and on subsequent warming, have been investigated by electron spin resonance (ESR) spectral analysis and (3) yields of main-chain scission and crosslinking have been measured by studying the molecular weight changes on irradiation using gel permeation chromatography (GPC).For poly[amino acid)s with aliphatic hydrocarbon side-chains, the main reactions were: (i) scission of the entire side-chain, and (ii) main-chain scission and fragmentation leading to elimination of a segment of the chain. When a carboxyl group was present in the side-chain, the main reaction was decarboxylation instead of main-chain scission. Aromatic protection was observed in polyphenylalanine and more effectively with the phenol group in polytyrosine. It has been proposed that g-irradiation of polypeptides causes ionization to give the polymeric radical cation, which undergoes chain scission to produce an amino cation and an alkyl radical, and that fragmentation occurs via the cation.The yields of volatile products, free radicals, main-chain scission and crosslinking from two random copolymers of glutamic acid and tyrosine after irradiation have been measured. The G values were substantially lower than the values corresponding to linear relationships between the homopolymers, attributable to protection by the aromatic groups. The number of glutamic acid units protected by a tyrosine unit has been calculated for decarboxylation, CO production and main-chain scission. The results suggest that a number of protection mechanisms may be involved.N-acetylamino acids have been considered by previous workers to be useful model compounds for the study of the effects of ionizing radiation on polypeptides. In this study, yields of (1) volatile products and (2) free radicals from g-radiolysis of a number of N-acetylamino acids in the polycrystalline state have been determined at 25dC. Carbon dioxide was found to be the major product. There was evidence for some scission of the N-Ca bond but deamination was found to be of much lesser importance than decarboxylation.The radicals formed on g-radiolysis of N-acetylvaline at -196dC, at 25dC and on subsequent warming over the range -196 to 167dC have been determined by ESR spectral analysis. A general mechanism for the radiation degradation of N-acetylamino acids has been suggested.The yields of alkanes and alkenes from g-irradiation of a series of copolymers of ethylene with propene, 1-butene and 1-hexene, and low- and high-density polyethylenes at temperatures from 25 to 175dC, have been measured to investigate (1) the nature and frequency of short-chain branching in polyolefins and (2) the mechanism of the radiation degradation." @default.
• W599716170 created "2016-06-24" @default.
• W599716170 creator A5014395430 @default.
• W599716170 date "2014-12-15" @default.
• W599716170 modified "2023-09-27" @default.
• W599716170 title "The radiation degradation of polymers and model compounds" @default.
• W599716170 doi "https://doi.org/10.14264/uql.2014.592" @default.
• W599716170 hasPublicationYear "2014" @default.
• W599716170 type Work @default.
• W599716170 sameAs 599716170 @default.
• W599716170 citedByCount "0" @default.
• W599716170 crossrefType "dissertation" @default.
• W599716170 hasAuthorship W599716170A5014395430 @default.
• W599716170 hasConcept C123460561 @default.
• W599716170 hasConcept C139066938 @default.
• W599716170 hasConcept C161790260 @default.
• W599716170 hasConcept C178790620 @default.
• W599716170 hasConcept C185592680 @default.
• W599716170 hasConcept C188027245 @default.
• W599716170 hasConcept C204921945 @default.
• W599716170 hasConcept C2778597550 @default.
• W599716170 hasConcept C2780595602 @default.
• W599716170 hasConcept C3044715 @default.
• W599716170 hasConcept C43617362 @default.
• W599716170 hasConcept C521977710 @default.
• W599716170 hasConcept C63179538 @default.
• W599716170 hasConcept C66887884 @default.
• W599716170 hasConcept C75473681 @default.
• W599716170 hasConceptScore W599716170C123460561 @default.
• W599716170 hasConceptScore W599716170C139066938 @default.
• W599716170 hasConceptScore W599716170C161790260 @default.
• W599716170 hasConceptScore W599716170C178790620 @default.
• W599716170 hasConceptScore W599716170C185592680 @default.
• W599716170 hasConceptScore W599716170C188027245 @default.
• W599716170 hasConceptScore W599716170C204921945 @default.
• W599716170 hasConceptScore W599716170C2778597550 @default.
• W599716170 hasConceptScore W599716170C2780595602 @default.
• W599716170 hasConceptScore W599716170C3044715 @default.
• W599716170 hasConceptScore W599716170C43617362 @default.
• W599716170 hasConceptScore W599716170C521977710 @default.
• W599716170 hasConceptScore W599716170C63179538 @default.
• W599716170 hasConceptScore W599716170C66887884 @default.
• W599716170 hasConceptScore W599716170C75473681 @default.
• W599716170 hasLocation W5997161701 @default.
• W599716170 hasOpenAccess W599716170 @default.
• W599716170 hasPrimaryLocation W5997161701 @default.
• W599716170 hasRelatedWork W1963981555 @default.
• W599716170 hasRelatedWork W1973802597 @default.
• W599716170 hasRelatedWork W1984124977 @default.
• W599716170 hasRelatedWork W2013062582 @default.
• W599716170 hasRelatedWork W2014873315 @default.
• W599716170 hasRelatedWork W2015256890 @default.
• W599716170 hasRelatedWork W2021144730 @default.
• W599716170 hasRelatedWork W2078270374 @default.
• W599716170 hasRelatedWork W2079298837 @default.
• W599716170 hasRelatedWork W2083563159 @default.
• W599716170 hasRelatedWork W2085395206 @default.
• W599716170 hasRelatedWork W2088203396 @default.
• W599716170 hasRelatedWork W2165775218 @default.
• W599716170 hasRelatedWork W2269590477 @default.
• W599716170 hasRelatedWork W232743214 @default.
• W599716170 hasRelatedWork W2905266751 @default.
• W599716170 hasRelatedWork W2956445089 @default.
• W599716170 hasRelatedWork W2969653947 @default.
• W599716170 hasRelatedWork W56215580 @default.
• W599716170 hasRelatedWork W2072497820 @default.
• W599716170 isParatext "false" @default.
• W599716170 isRetracted "false" @default.
• W599716170 magId "599716170" @default.
• W599716170 workType "dissertation" @default.