Allan R. Shultz

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCoumarins in Polymers: From Light Harvesting to Photo-Cross-Linkable Tissue ScaffoldsScott R. Trenor, Allan R. Shultz, Brian J. Love, and Timothy E. LongView Author Information Polymeric Materials and Interfaces Laboratory, Department of Chemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0344 Cite this: Chem. Rev. 2004, 104, 6, 3059–3078Publication Date (Web):May 6, 2004Publication History Received20 October 2003Published online6 May 2004Published inissue 1 June 2004https://pubs.acs.org/doi/10.1021/cr030037chttps://doi.org/10.1021/cr030037cresearch-articleACS PublicationsCopyright © 2004 American Chemical SocietyRequest reuse permissionsArticle Views11453Altmetric-Citations697LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Aromatic compounds,Irradiation,Oligomers,Polymers,Reaction products Get e-Alerts

Abstract The solution viscosity behavior of polymers previously irradiated by high‐energy sources is treated theoretically by a combination of existing random crosslinking and degradation theory and branched‐polymer solution viscosity theory. The derived relations are applied to data on polystyrene, polymethyl methacrylate and poly‐ tert ‐butyl methacrylate irradiated as films in air with 1000 kvp. electrons. Polystyrene films underwent gelation exhibiting an energy dissipation per crosslinked unit E c = 855 electron volts and a main‐chain scission to crosslinked unit ratio α/β = 0.35. Pregelation light‐scattering molecular weights of the irradiated polystyrene predicted an incident gelation dose (9.4 megareps) in good agreement with that (10.3 megareps) observed by gel measurements. Theory satisfactorily reproduced the solution viscosity data over a wide range of pregelation radiation doses. A combination of light‐scattering and intrinsic viscosity data proved conclusively that no appreciable crosslinking occurs during the degradation of polymethyl methacrylate under 1000 kvp. electrons. The apparent energy dissipation per main‐chain scission, E d = 58–62 e.v., determined by viscometry is therefore the true E d in this instance. Reactions leading to crosslinking in polyacrylates are either blocked or diverted by the methyl group on the polymethacrylate backbone. Poly‐ tert ‐butyl methacrylate degrades under electron bombardment with an E d = 43 e.v.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDEGRADATION OF POLYMETHYL METHACRYLATE BY ULTRAVIOLET LIGHTAllan R. ShultzCite this: J. Phys. Chem. 1961, 65, 6, 967–972Publication Date (Print):June 1, 1961Publication History Published online1 May 2002Published inissue 1 June 1961https://pubs.acs.org/doi/10.1021/j100824a019https://doi.org/10.1021/j100824a019research-articleACS PublicationsRequest reuse permissionsArticle Views615Altmetric-Citations73LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access options Get e-Alerts

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDSC on Freeze-Dried Poly(methyl methacrylate)-Polystyrene BlendsAllan R. Shultz and Ann L. YoungCite this: Macromolecules 1980, 13, 3, 663–668Publication Date (Print):May 1, 1980Publication History Published online1 May 2002Published inissue 1 May 1980https://pubs.acs.org/doi/10.1021/ma60075a034https://doi.org/10.1021/ma60075a034research-articleACS PublicationsRequest reuse permissionsArticle Views681Altmetric-Citations70LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

Abstract The crosslinking and degradation of seven polyacrylates by 1000 kvp. electrons has been investigated. Gel content‐radiation dose analysis reveals the energy dissipation per main‐chain fracture, E d , to be the same (530 ± 100 electron volts) for methyl, n ‐butyl, sec ‐butyl, isobutyl, and tert ‐butyl acrylate polymers. The energy dissipation per crosslinked unit formation, E c , is 80–90 e.v. for methyl, n ‐butyl, isobutyl and neopentyl acrylate polymers. E c may be slightly higher for poly‐ sec ‐butyl acrylate. Poly‐ tert ‐butyl acrylate possesses a uniquely high E c of 300 e.v. The presence of hydrogen atoms alpha to the alcoholic oxygen of the ester group is believed to contribute strongly to the crosslinking reactions of polyacrylates under ionizing radiations. Poly‐1,1‐dihydroperfluorobutyl acrylate exhibits an initial E c of ∼45 e.v. and an E d of ∼450 e.v. Beyond 15 megareps the ration of main‐chain fracture to crosslink formation increases.