The Effect of ω-Substituted Acceptors in 4-Dimethylamino-trans-Styrenes on the Polarity in the Ground and Excited Singlet State
ABSTRACT The electric dipole moment in the ground (μg) and in the first excited singlet state (μe) of co-substituted acceptors in 4-dimethylamino-trans-styrenes (Z = P(S)Ph2 , P(O)Ph2 , SO2CH3 ) were determined by solvatochromic and thermochromic methods. The obtained values of μe and μg and the values for Z = CN and Z = NO 2 known from the literature [2] fulfill the linear relation between the dipole moments (μe or μg and the Hammett constants σp of the substituents. On pincreasing the electron-acceptor power of Z, μe grows faster than μg
Molecular Relaxation Processes During Film Formation
Traditionally many coatings and polymer chemists and physicists who follow the increase in viscosity of coating materials as changes occur during drying, use only one-point or steady-state methods for monitoring the ‘cure’. Insight can be gained by determining a flow curve at various shear rates for coating binders and formulations. However, as a proper formulated coating begins the process of changing from a liquid which generally flows readily to a solid coating, all are viscoelastic in nature. Such is the case with industrial, architectural or special protective coatings manufactured by the paint industry and printing inks, adhesives, paper coatings or other similar types. Only a few materials of commercial importance are not viscoelastic in normal usage, e.g. some Newtonian oils. Since this is the case, it is important for scientists not only to measure the viscosity of a coating but also to know something about the elastic response of the material.
Barbarians, Gentlemen and Players : A Sociological Study of the Development of Rugby Football
Part I: Folk Antecedents and Transitional Forms of Football in the Public Schools 1. The folk antecedents of modern rugby and their decline 2. Football in the early 19th century public schools Part II: The Modernisation of Rugby Football 3. The preconditions for modernization: embourgeoisement and public school reform 4. The incipient modernization of rugby football 5. The 'civilising process' and the formation of the RFU. 6. The democratization of rugby football. 7. Professionalisation and the amateur response. 8. The split. 9. The class structure and the professionalisation of British sport. Part III: The Development of Rugby Football as a Modern Sport 10. The professionalisation of rugby league. 11. Rugby union as a modern sport: bureaucracy, gate-taking clubs and the swansong of amateurism. Conclusion: Sociological Reflections on the Crisis in Modern Sport