Abstract Thermal oxidations at 101°C of ethylene‐carbon monoxide (E/CO) copolymer and low‐density polyethylene (DYNK) were studied over the range of 0–30 mL oxygen absorbed per gram of polymer. Relative changes in reaction rates, chemical composition, and molecular weights of the polymers were observed using oxygen uptake, infrared spectroscopy, and gel permeation chromatography. At comparable oxidation rates, differences in concentrations of most functional groups appeared to be small, except for the IR peak attributed to non‐hydrogen‐bonded hydroperoxide which was absent in the spectrum of E/CO copolymer. The extent of scission at comparable oxygen absorption was greater in E/CO than DYNK, since ketonic carbonyl groups were oxidized faster than methylene groups.
Abstract The hydrolytic stability of glass fiber reinforced poly(butylene terephthalate) (PBT), poly(ethylene terephthalate) (PET) and polycarbonate (PC) was studied. The activation energies in kcal/mole for hydrolysis are 26 for PBT and 23 for PET. Both PBT and PET contain 30 percent glass fiber reinforcement. The hydrolysis rates for a series of experimental PC's containing 10, 30 and 40 percent glass were obtained from GPC data. These increase with glass concentration but are lower than that of the unreinforced PC. Melt flow rate changes are a good measure of the hydrolytic degradation of PET. However, in the time scale of these experiments, the tensile properties of glass reinforced PBT and PC do not correlate well with M̄ w changes, unlike unreinforced PBT and PC polymers. Consequently, to compare these three glass fiber reinforced polymers, estimates of failure time must be based on changes in tensile strength rather than melt flow rate.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEffects of elongation on the photochemistry of poly(ethylene-co-carbon monoxide)Robert Gooden, Don D. Davis, Molly Y. Hellman, Andrew J. Lovinger, and Field H. WinslowCite this: Macromolecules 1988, 21, 5, 1212–1217Publication Date (Print):May 1, 1988Publication History Published online1 May 2002Published inissue 1 May 1988https://pubs.acs.org/doi/10.1021/ma00183a005https://doi.org/10.1021/ma00183a005research-articleACS PublicationsRequest reuse permissionsArticle Views75Altmetric-Citations19LEARN 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
Gel permeation chromatography and infrared spectra have been used to characterize several poly(phenylene oxide) films formed by the anodic oxidation of aqueous phenol solutions. For the 2,6‐dimethyl derivative, the molecular weight distribution extends to 10,000. Infrared spectra confirm a head‐to‐tail coupling structure. Results are also reported for films derived from 4‐t‐butylphenol and 2,4,6‐trimethylphenol.
Abstract A technique has been developed for the identification of phthalate plasticizer components using high speed liquid chromatography. The plasticizers recovered from post consumer scrap PVC have been analyzed.
One of the methods under development at AT&T Bell Laboratories for submicron lithography is deep ultraviolet projection photolithography. (1) Fine line definition is obtained by use of 248 nm light and a lens of large numerical aperture. Because of the large chromatic aberration of the quartz lens a spectrally line-narrowed krypton fluoride excimer laser is used as a light source. Microposit 2400 resist, manufactured by Shipley Co., has been shown to be sensitive at this short wavelength (2) and is being employed with the deep UV stepper. We report here the results of resist profile modeling for submicron photolithography at 248 nm. Various model parameters needed as input data were measured to characterize exposure and development of the resist. Determination of Resist Parameters. Most resists are designed for exposure at wavelengths longer than the 248.4 nm radiation provided by a KrF laser source. Wolf and coworkers (3) have found that
Abstract The radiation chemistry of poly(vinyl chloride) (PVC) blended with trimethylolpropanetrimethacrylate (TMPTMA) and diundecyl phthalate (DUP) has been examined. This three‐component mixture contains a base resin (PVC), a crosslinking sensitizer (TMPTMA), and a physical modifier (DUP). These are the basic components in any radiation‐curable coating. The kinetics and mechanism of the crosslinking reactions were studied with reference to the dependence on radiation dose and blend composition. The polyfunctional TMPTMA underwent polymerization incorporating the PVC into a 3‐dimensional network. DUP remained chemically inert during the irradiation, not being bound to the network. However, DUP by plasticizing the macromolecules and diluting the monomer, changed the kinetics extensively. DUP enhanced TMPTMA homopolymerization, TMPTMA grafting, and PVC crosslinking reaction rates. The effect on the competition between polymerization, grafting, and degradation reactions was examined in terms of enhanced mobility of the reacting species. The influence of these kinetic considerations in selecting a blend composition for a coating application was discussed.
