Nitrogen oxides are common by-products of fossil fuel combustion and are one of the most significant types of air pollution. The nitric oxides react with UV radiation to form oxides of nitrogen, ozone and acids. The nitrogen oxides can have considerable impact of the life of polymers in the environment and can be responsible for failure of polymer products, so it is important to know how these effects will manifest. Most of the earlier studies of the effect of nitrogen oxides on polymeric materials have involved the determination of changes in the average molecular weight and mechanical properties, as well as changes in chemical structure using infrared spectroscopy. However, these characteristics provide no direct information on the mechanism of intermediate stages of the complicated processes of polymer degradation under the action of these aggressive gases. In this book, novel results obtained by other physicochemical methods especially electron spin resonance spectroscopy are considered for various polymers. The influence of different functional groups on the mechanism of interaction of nitrogen oxides with polymers are discussed. The features of ion-radical initiation of conversions of polymers by dimers of nitrogen dioxide are also considered. Various other techniques for studying these interactions are also discussed. This handbook will be of interest to all those who produce polymer products that are likely to spend their life in an outdoors environment. It will also be useful to the manufacturers of raw materials used in these products. Technicians who are involved in material testing will also find a wealth of information about testing for the effects of ozone on polymers.
Author(s): Gennady Zaikov
Year: 2009
Language: English
Pages: 276
Introduction......Page 12
1 Classification of Polymers with respect to Reactivity toward Nitrogen Oxides......Page 14
1.2 Interaction of Rubbers with NO2......Page 18
1.3 Interaction of NO2 with Aliphatic Polyamides and Polyurethanes......Page 21
References......Page 24
2.1 Structure and Physical Properties of Stable Radicals......Page 26
2.2 ESR Spectroscopy of ARs......Page 28
2.3 Chemical Properties of ARs......Page 31
2.4 Applications of ARs......Page 37
2.5 Generation of ARs in Reactions of Spin Trapping......Page 39
2.6 Synthesis of Polymers Containing Stable ARs......Page 44
References......Page 57
3 Interaction of Polymers with Nitric Oxide......Page 66
3.1 Interaction of NO with Organic Compounds......Page 67
3.2.1 Synthesis of Spin-Labelled Fluorinated Polymers by Free-Radical Reaction in the Presence of NO......Page 81
3.2.2 Photolysis of Polymethylmethacrylate and Acetyl Cellulose in NO......Page 91
3.3 Interaction of Polymeric Hydroperoxides with NO......Page 93
References......Page 98
4.1 Methods of Generation of NO3......Page 104
4.2 Photochemistry of NO3......Page 109
4.3 Interaction of NO3 with Organic Compounds......Page 110
4.4 Cross-linking of Macromolecules via the Photoreactions of NO3......Page 121
References......Page 131
5.1 Reactions of NO2 with Alkanes......Page 136
5.2 Reactions of NO2 with Aromatic Compounds......Page 143
5.3 Reactions of NO2 with Phenols......Page 161
5.4. Interaction of NO2 with Alkenes, Dienes and Polyenes......Page 172
5.5 Radical Conversions of p-benzoquinones in Reactions with NO2......Page 182
References......Page 189
6.1 Formation of Spin-Labelled Polymers in Reactions of NO2 with the Double Bonds of Macromolecules......Page 196
6.2 ESR Imaging in Studies of the Spatial Distribution of the Reaction Front of NO2 in Polymers......Page 202
6.3 Polymer Degradation in Reactions of Peroxide Macroradicals with NO2......Page 204
References......Page 207
7.1 Formation of Nitrosonium Complexes from Organic Compounds and NO2......Page 210
7.2 Direct Experimental Detection of Primary Radical Cations and Products of Their Decomposition in the Reactions of Nitrosyl Nitrate......Page 217
7.3 Oxidative Generation of Stable Nitrogen-Containing Radicals in Aliphatic Polyamides and Polyvinylpyrrolidone......Page 227
7.4 Ion-Radical Conversions of Aromatic Polyamides in the Presence of NO2......Page 230
7.5 Oxidative Radical Generation via NO2 Dimer Conversions Induced by the Amide Groups of Macromolecules......Page 240
7.6 Interaction of Aromatic Polyimides with NO2......Page 245
References......Page 255
Abbreviations......Page 260
Index......Page 264
