. " electron spin resonance imaging (ESRI)" . " hindered amine stabilizers (HAS)" . . "Studium prostorov\u00E9 heterogenity foto- a termo-degradace tuh\u00FDch polymer\u016F modern\u00EDmi fyzik\u00E1ln\u00EDmi metodami" . "6"^^ . "Spatial heterogeneity of photo- and thermo-degradation of solid polymers by modern physical methods"@en . "Heterogeneity of photodegradation inside polymers stabilized by HAS depends on diffusion transmittance of the polymers in the range of terrestrial part of solar UV radiation and on the ratio of polymer radicals P oxidation and recombination reactivity."@en . "6"^^ . . . . . . . . . . . "0"^^ . . " spatial hetrogeneity of thermodegradation" . "1"^^ . . "0"^^ . . " solid polymers" . "2008-01-01+01:00"^^ . . "Heterogenita fotodegradace uvnit\u0159 polymer\u016F stabilizovan\u00FDch stericky st\u00EDn\u011Bn\u00FDmi aminy z\u00E1vis\u00ED na dif\u00FAzn\u00ED transmitanci polymer\u016F v oblasti terrestri\u00E1ln\u00ED slo\u017Eky slune\u010Dn\u00EDho UV z\u00E1\u0159en\u00ED a na pom\u011Bru reaktivity polymern\u00EDch radik\u00E1l\u016F P p\u0159i oxidaci a p\u0159i rekombinaci."@cs . "http://www.isvav.cz/projectDetail.do?rowId=IAA400500804"^^ . . "Zdokonalen\u00ED komplexn\u00ED ochrany polymer\u016F p\u0159ed zhor\u0161ov\u00E1n\u00EDm jejich vlastnost\u00ED v souvislosti se st\u00E1rnut\u00EDm vyu\u017Eit\u00EDm kooperativity p\u016Fsoben\u00ED stabiliz\u00E1tor\u016F a sou\u010Dasn\u00E9 zlep\u0161en\u00ED jej\u00ED ekonomiky optimalizac\u00ED koncentrace stabiliz\u00E1tor\u016F v polymerech vy\u017Eaduje lep\u0161\u00ED znalosti mechanizm\u016F degradace. V tomto projektu se zam\u011B\u0159\u00EDme na studium koncentra\u010Dn\u00EDch gradient\u016F meziprodukt\u016F a produkt\u016F foto- a termo-degradace uvnit\u0159 stabilizovan\u00FDch amorfn\u00EDch i semikrystalick\u00FDch polymer\u016F (polypropylen, polystyren, polyethylen, poly(ethylen-co-norbornen). Technikou prostorov\u00E9ho zobrazen\u00ED elektronov\u00E9 spinov\u00E9 rezonance (ESRI) budeme zji\u0161\u0165ovat koncentra\u010Dn\u00ED profily nitroxid\u016F, kter\u00E9 jsou kl\u00ED\u010Dov\u00FDmi meziprodukty p\u016Fsoben\u00ED stabiliz\u00E1tor\u016F na b\u00E1zi st\u00EDn\u011Bn\u00FDch amin\u016F (HAS), v z\u00E1vislosti na dob\u011B urychlen\u00E9ho st\u00E1rnut\u00ED polymer\u016F. Ve stejn\u00E9 z\u00E1vislosti budeme studovat zm\u011Bny transparentnosti polymer\u016F, koncentrace karbonylov\u00FDch a hydroxylov\u00FDch skupin na povr\u0161\u00EDch a uvnit\u0159 vzork\u016F a zm\u011Bny n\u011Bkter\u00FDch integr\u00E1ln\u00EDch mechanick\u00FDch vlastnost\u00ED polymer\u016F." . "2013-06-28+02:00"^^ . "spatial hetrogeneity of photogegradation" . "IAA400500804" . . "2011-03-18+01:00"^^ . . . "2011-12-31+01:00"^^ . "spatial hetrogeneity of photogegradation; spatial hetrogeneity of thermodegradation; solid polymers; hindered amine stabilizers (HAS); electron spin resonance imaging (ESRI); transparency of solid polymers"@en . "Better protection of polymers against deterioration of their properties due to weathering using cooperation between stabilizers and improving economy of protection by optimization concentration of stabilizers requires better understanding of degradation mechanisms. In this project we will focus on finding out concentration gradients of intermediates and products of photo- and thermo-degradation inside stabilized amorphous and semicrystalline polymers (polypropylene, polystyrene, polyethylene, poly(ethylene-co-norbornene). Concentration profiles of nitroxides, key intermediates in the protection mechanism of hindered amine stabilizers (HAS), will be determined by electron spin resonance imaging (ESRI) in dependence on the duration of the accelerated weathering. In the same dependence changes in polymer transparency, changes in concentrations of carbonyl and hydroxy groups on the surface and inside the samples, and changes of integral mechanical properties of polymers will be studied."@en .