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  • 1
    Electronic Resource
    Electronic Resource
    Graft copolymerization of vinyl monomers onto modified cottons, X. Hydrogen peroxide induced grafting of styrene onto cellulose carbamate (1978)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 70 (1978), S. 87-99 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Pfropfung von Styrol auf Cellulosecarbamat wurde unter verschiedenen Bedingungen in Gegenwart von H2O2 als Initiator untersucht. Es wurde gefunden, daß die Pfropf-Ausbeute von der Menge an Carbamatgruppen, Initiator und Monomeren ebenso wie von Temperatur und pH bei der Polymerisation abhängig ist. Die Pfropf-Ausbeute nahm mit steigender H2O2-Konzentration zu, erreichte ein Maximum bei 0.18% H2O2 und fiel dann plötzlich ab. Die maximale Pfropfung trat bei einer Monomerkonzentration von 6.6% ein. Die Pfropf-Ausbeute nahm auch bei Erhöhung der Polymerisationstemperatur bis auf 90°C zu. Eine Erhöhung des pH-Wertes von 2 auf 4 ließ die Pfropfausbeute deutlich absinken. Auch der Zusatz von FeSo4 verursachte eine erhebliche Verringerung der Pfropf-Ausbeute. Ein Vergleich zeigt, daß Cellulosecarbamat mit weniger als 1.1% Stickstoffgehalt eine niedrigere Pfropf-Ausbeute als nicht modifizierte Cellulose ergibt. Oberhalb dieses Stickstoffgehalts läßt sich Cellulosecarbamat besser pfropfen als die nicht modifizierte Cellulose.
    Notes: Grafting of styrene onto cellulose carbamate was investigated under a variety of conditions using H2O2 as initiator. The graft yield was found to depend on the amount of carbamate groups, initiator and monomer concentrations as well as on temperature and pH of polymerization. The graft yield increased with increasing H2O2 concentration, attained a maximum at a concentration of 0.18% then fell down sharply. Maximal grafting occurred at a monomer concentration of 6.6%. The graft yield increased also by raising the polymerization temperature up to 80°C, attained maximum at 90°C then decreased significantly. With respect to pH, the graft yield decreased markedly upon increasing the pH from 2 to 4 and marginally upon further increase in pH. Addition of FeSO4 to the polymerization system caused a considerable decrement in the graft yield. A comparison between the graft yield obtained with the modified cellulose having different amounts of carbamate groups with those of the unmodified cellulose indicated that cellulose carbamates having less than 1.1% nitrogen showed lower graft yields than the unmodified cellulose. Above this, cellulose carbamate was much more amenable to grafting than the unmodified cellulose.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1978.050700108
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  • 2
    Electronic Resource
    Electronic Resource
    Graft copolymerization of perfluoroheptyl methacrylate/glycidyl methacrylate mixtures with cotton fabric using Fe2+-thioureadioxide-H2O2 redox system (1985)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 130 (1985), S. 137-146 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Das Redox-System aus Fe2+, Thioharnstoffdioxid und H2O2 erwies sich als brauchbar, die Pfropfcopolymerisation von Perfluorheptyl-methacrylat (PFHMA) und Glycidylmethacrylat (GMA) sowie der Mischung beider unter verschiedenen Bedingungen zu initiieren. Die erhaltenen Ergebnisse zeigen: (a) PFHMA kann nur auf Baumwollcellulose gepfropft werden, wenn noch GMA in der Mischung vorhanden ist. (b) Den höchsten PFHMA-Anteil im Pfropfcopolymerisat erhält man bei 80°C und einem Monomerverhältnis PFHMA : GMA = 50:50. (c) PFHMA setzt bei höheren Temperaturen die hohe Abbruchgeschwindigkeit von GMA herab. (d) GMA aktiviert PFHMA, aber PFHMA deaktiviert GMA. (e) Es treten keine synergistischen Effekte auf. (f) Die optimalen Bedingungen liegen vor bei: 0,01% H2O2, 0,04% Thioharnstoffdioxid, Monomerverhältnis 50:50. (g) Am Anfang verläuft die Pfropfcopolymerisation sehr schnell, dann läßt die Geschwindigkeit nach. (h) Das Wasser/Öl-Abweisungsvermögen beruht auf dem PFHMA-Anteil; es ist bei 4,25% PFHMA bei einem Gesamtpfropfgehalt von 22,5% am höchsten.
    Notes: The ability of Fe2+-thioureadioxide-H2O2 redox system to induce polymerization of perfluoroheptyl methacrylate (PFHMA) and glycidyl methacrylate (GMA) individually as well as in binary mixtures was investigated under different conditions. Results obtained indicated that (a) PFHMA monomer could substantially be polymerized with cotton cellulose only in presence of GMA, (b) maximum contribution of PFHMA in the polymer add-on occurred upon using PFHMA mixture at a ratio of 50:50 at 80°C, (c) presence of PFHMA along with GMA offsets the fast termination rate of the latter as temperature increased from 60° to 90°C, (d) GMA activated PFHMA while the latter adversely affected GMA, (e) none of the PFHMA/GMA mixtures at ratios 2:8, 5:5, 8:2 showed synergetic effects, (f) H2O2 concentration of 0.01% and thioureadioxide concentration of 0.04% constituted the optimal concentrations for polymerization of PFHMA/GMA at a ratio of 5:5, and (g) the polymerization reaction proceeded initially very fast, then levelled off. (h) The water/oil repellency of the copolymerized cotton samples relied on the percent of PFHMA in total percent polymer add-on; these properties attained maximum at 4.25% PFHMA in a total polymer add-on of 22.5%.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1985.051300111
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  • 3
    Electronic Resource
    Electronic Resource
    Polymerization of glycidyl methacrylate, methacrylic acid, acrylamide and their mixtures with cotton fabric using fe2+-thioureadioxide-H2O2 redox system (1982)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 103 (1982), S. 61-76 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Polymerisation von Glycidylmethacrylat (GMA), Methacrylsäure (MAA), Acrylamid (Aam) und ihrer binären Mischungen wurde mit Baumwolle-Cellulose-Geweben unter verschiedenen Bedingungen mit einem Fe2+-Thioharnstoffdioxid-H2O2-Redox-System untersucht. Die optimalen Polymerisationstemperaturen für GMA, MAA, Aam und GMA/MAA (8:2) lagen bei 50, 80, 65 bzw. 95°C, für GMA/MAA (2:8), Aam/MAA (8:2) und Aam/MAA (2:8) bei 75°C. Die Polymerisation war am Anfang sehr schnell, später wurde sie langsamer, unabhängig vom Monomeren oder der Monomermischung. Die Pfropfausbeute nach der Verlangsamung der Polymerisation folgte der Reihe GMA 〉 GMA/MAA (2 : 8) ≥ GMA/MAA (8 : 2) 〉 Aam / MAA (2 : 8) ≥ MAA ≥ Aam/MAA (8 : 2) 〉 Aam. Die Pfropfausbeute stieg mit steigender H2O2-Konzentration bis zu einem bestimmten Punkt, dann wurde sie wieder geringer. Dasselbe geschah bei steigender Thioharnstoffdioxid-Konzentration. Der Epoxy-Ring von GMA reagierte mit MAA während der Polymerisation der Mischung mit Cellulose nur bei einem höheren GMA-Verhältnis in der Mischung. Ebenso konnte ein wesentlicher Beitrag von Aam auf das Aufgepfropfte in einer Aam/MAA-Mischung nur bei einem häheren Aam-Verhätnis in der Mischung erreicht werden.
    Notes: Polymerization of glycidyl methacrylate (GMA), methacrylic acid (MAA), acrylamide (Aam) and their binary mixtures with cotton cellulose fabrics using Fe2+-thioureadioxide-H2O2 redox system was investigated under a variety of conditions. While temperatures of 50, 80, 65, and 95°C constituted the optimal polymerization temperature for GMA, MAA, Aam and GMA/MAA (8:2), respectively, maximum polymerization of GMA/MAA (2:8), Aam/MAA (8:2) and Aam/MAA (2:8) occurred at 75°C. The polymerization reaction proceeded initially very fast then levelled off irrespective of the monomer or monomer mixtures used. However, the magnitude of the polymer add-on at levelling off of polymerization followed the order GMA 〉 GMA/MAA (2:8) ≥ GMA/MAA (8:2) 〉 Aam/MAA (2:8) ≥ MAA ≥ Aam/MAA (8:2) 〉 Aam. The polymer add-on enhanced by increasing the H2O2 concentration up to a certain limit and then decreased. The same situation was encountered with respect to thioureadioxide concentration. The involvement of the epoxy ring of GMA with MAA during polymerization of their mixture with cellulose occurred only at a higher ratio of GMA in the mixture. Also a significant contribution of Aam in the polymer add-on obtained with a Aam/MAA mixture could only be achieved at a higher ratio of Aam in this mixture.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1982.051030106
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  • 4
    Electronic Resource
    Electronic Resource
    Ce(IV)-induced polymerization of allyl methacrylate with cotton cellulose (1981)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 19 (1981), S. 3137-3143 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ce(IV)-induced polymerization of allyl methacrylate (AMA) with cotton cellulose was investigated under a variety of conditions. Polymer add-on was directly related to AMA concentration. The same holds good for Ce(IV) ion concentration up to a certain concentration (30 mmol/L), after which it decreases. Polymer add-on was higher at 60 than at 50 and 70°C. A methanol/water mixture (20/80) offers the best medium for polymerization. Addition of nitric acid (up to 400 mol equivalent/L) or perchloric acid (up to 800 mol equivalent/L) to the polymerization system caused significant enhancement in polymer add-on. The reverse was the case with sulphuric acid irrespective of the concentration used. A comparison between polymer add-on values based on increase in weight and those based on estimated allyl double bonds indicated that the latter undergo partial homopolymerization.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1981.170191208
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  • 5
    Electronic Resource
    Electronic Resource
    Graft copolymerization of vinyl monomers onto modified cottons. XII. Grafting of 1,1-dihydroperfluoroheptyl acrylate onto cellulose carbamate using hydrogen peroxide as initiator (1980)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 25 (1980), S. 223-233 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Cellulose carbamate having 1.4% N was grafted with 1,1-dihydroperfluoroheptyl acrylate (DHPFHA) using H2O2 as initiator under a variety of conditions. The technique used involved padding the fabric in H2O2 solution at room temperature followed by impregnating it in an aqueous emulsion of DHPFHA. The graft yield, expressed as fluorine percent, was found to depend upon monomer and initiator concentration, temperature, and reaction time and pH of the polymerization medium as well as upon the carbamate content of the modified cotton. Increasing the monomer concentration up to 5% caused a considerable enhancement in grafting. The same holds true for initiator concentration up to a certain limit after which the grafting decreases. Raising the reaction temperature up to 100°C was accompanied by an increment in the magnitude of grafting reaction. The latter was characterized by an initial fast rate followed by a slower rate. Slightly acidic media (pH 5-6) proved to be the best for performing grafting. The graft yields were quite poor when grafting was carried out in acidic (pH 2-4) or alkaline (pH 8-12) media. The presence of a relatively smaller amount of carbamate groups in the cellulose molecules decreases its susceptibility to grafting. The opposite holds true for larger amounts. Incorporation of FeSO4 at low concentration in the monomer emulsion had no effect on the graft yield. However, the latter decreases at higher FeSO4 concentration. Grafted cellulose carbamate having ca. 15% fluorine showed very good oil and water repellency. The grafted product retained ca. 85% of the strength of cellulose carbamate.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1980.070250208
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  • 6
    Electronic Resource
    Electronic Resource
    Mechanisms of degradation of cotton and effects of mercerization-stretching upon the course of these mechanisms. V. Weathering (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 26 (1981), S. 2713-2725 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Scoured ply cotton yarn was slack mercerized followed by restretching the cotton yarn to 90-103% of the original length in the mercerizing solution. The scoured and the mercerized cotton yarns were subjected to weathering for up to 14 months. Regardless of the cotton substrates, exposure to weathering was accompanied by an increase in copper number, decrease in both degree of polymerization (DP) and iodine sorption, and a loss in strength properties. No significant change in the carboxyl content of scoured and mercerized cottons could be observed after weathering. However, mercerized cottons retained higher strength in spite of higher degradation as compared to scoured cotton. This was interpreted in terms of removal of structural imperfections or weak links in cotton during the combined as swelling and stretching process evidenced by interrelationships between tenacity and percentage of bonds broken, as well as tensile strength and DP together with measurement of the average distances between crystallite centers in scoured and mercerized degraded cotton.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1981.070260819
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  • 7
    Electronic Resource
    Electronic Resource
    Chemical factors affecting soiling and soil release from cotton-containing durable press fabric. VIII. Grafting of polyester/cotton blend fabrics with carboxyl-containing polymerThis research has been financed in part by a grant made by United States Department of Agriculture, Agricultural Research Service, authorized by Public Law 480. (1983)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 28 (1983), S. 1179-1193 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Fabric samples of polyester/cotton blend were graft copolymerized to different levels (add-ons) with poly(acrylic acid) and poly(methacrylic acid) using the mutual γ-irradiation technique and the Fe2+-H2O2 redox system, respectively. The copolymers so obtained were given durable press treatments with and without conventional nonionic softener using DMDEU as the crosslinking agent. The susceptibility of the copolymers before and after crosslinking to aqueous and nonaqueous oily soiling and their ability to release the soils were examined. It was found that hydrophilization of the surface of polyester/cotton blend through grafting with the said carboxyl-containing polymers brings about a significant improvement in the resistance of the blend to aqueous and nonaqueous oily soil particularly after crosslinking in presence of nonionic softener. A certain improvement in the ease of oily soil removal could be achieved by grafting. The opposite holds true for aqueous soil release. Soiling and soil release depends on the magnitude and method of grafting, medium of soiling, as well as the formulation of crosslinking treatments. The effect of grafting on some properties of the blend fabric before and after crosslinking was also examined.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1983.070280323
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  • 8
    Electronic Resource
    Electronic Resource
    Fe2+-Thioureadioxide-H2O2-induced polymerization of glycidyl methacrylate and its mixtures with acrylamide, acrylonitrile, butylmethacrylate, or styrene with cotton fabric (1982)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 27 (1982), S. 2105-2117 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Fe2+-thioureadioxide-H2O2-induced polymerization of glycidyl methacrylate (GMA) and its mixtures with acrylamide (Aam), acrylonitrile (AN), butylmethacrylate (BMA), or styrene was investigated at different temperatures (50-95°C), for different periods of time (5-130 min) using different concentrations of Fe2+-thioureadioxide and H2O2. The add-on increased by increasing the thioureadioxide concentration up to 0.05% then decreased. H2O2 concentration of 0.005% constituted the optimal for GMA and GMA/Aam mixtures, and 0.02% H2O2 for GMA/AN, GMA/BMA and GMA/styrene mixtures. Increasing the concentration of GMA either alone or in admixtures resulted in improved add-ons; the magnitude of this improvement relied on the nature of the monomer used along with GMA. The polymerization reaction was characterized by an initial fast rate followed by a slower one irrespective of monomer or monomer mixtures used. Presence of Aam along with GMA offset the fast termination observed with the latter at higher temperatures (above 60°C). GMA/Aam mixtures produced higher add-ons than Aam alone irrespective of their rations in the mixtures, indicating activation of Aam with GMA. On the other hand, Aam deactivated GMA. Similar situation was encountered when styrene or acrylonitrile was used instead of Aam except that the percent add-ons obtained with GMA/AN mixtures decreased upon raising the polymerization temperature above 80°C. Contribution of GMA in the add-ons obtained with the different mixtures was also examined. For instance, the add-on was composed mainly of poly(GMA) when GMA/Aam at a ratio of 8:2 was used. On the other hand, using GMA/Aam at a ratio of 2:8 brought about add-ons of poly(GMA/Aam) in which the concentration of GMA and Aam were roughly equal.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1982.070270622
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  • 9
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    Detection of Phishing Websites Based on Probabilistic Neural Networks and K-Medoids Clustering (2018)
    Oxford University Press
    Details
    Publication Date: 2018-03-06
    Description: With the increasing rate and catastrophic consequences of phishing attacks, research on anti-phishing solutions has gained growing importance in information security. Security risks may include information leakage, identity theft, financial loss and reputation sabotage. Raising human awareness is not a sufficient mitigation method and deploying complementary technical solutions is a crucial requirement. Although various approaches have been proposed in the literature, the design of efficient phishing detection models is a challenging task and the problem still lacks a complete solution. In this paper, we present a novel approach for detecting phishing websites based on probabilistic neural networks (PNNs). We also investigate the integration of PNN with K -medoids clustering to significantly reduce complexity without jeopardizing the detection accuracy. To assess the feasibility of the proposed approach, we conducted in-depth study to evaluate various performance measures on a publicly available data set composed of 11 055 phishing and benign websites. The experimental results show that more accurate models can be built and even with 〉40% reduction in the complexity, 〉97% accuracy can be achieved with low false errors.
    Print ISSN: 0010-4620
    Electronic ISSN: 1460-2067
    Topics: Computer Science
    Published by Oxford University Press
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  • 10
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    Combining spatial and DCT based Markov features for enhanced blind detection of image splicing (2014)
    Springer
    Details
    Publication Date: 2014-08-06
    Print ISSN: 1433-7541
    Electronic ISSN: 1433-755X
    Topics: Computer Science
    Published by Springer
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