Experimental Studies of Bulk Melts, Networks and Concentrated Solutions

Experimental Studies of Bulk Melts, Networks and Concentrated Solutions 

In this section a series of experimental NMR studies based on the techniques described above will be compared with predictions of the model theories. Of course, any model is based on idealizations approaching reality only under certain conditions. The objective of the first few paragraphs will therefore be to demonstrate the rich variety of phenomena that can influence polymer dynamics. It will be elucidated under what circumstances the essence of the model theories and their predicted limits comes to light. We will first consider three basic features of polymer dynamics, namely the three dynamic components governing molecular motions of polymer chains, the dynamics of chain-end blocks in contrast to the central segment block, and how free volume and voids influence dynamics and the appearance of NMR measur-ands. 

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Apart from the introductory section, the article is subdivided into four major sections NMR Methods Modeling of Chain Dynamics and Predictions for NMR Measurands Experimental Studies of Bulk Melts, Networks, and Concentrated Solutions and Chain Dynamics in Pores. First, the NMR techniques of interest in this context will be described. Second, the three fundamental polymer dynamics theories, namely the Rouse model, the tube/reptation model, and the renormalized Rouse theories are considered. The immense experimental NMR data available in the literature will be classified and described in the next section, where reference will be made to the model theories wherever possible. Finally, recent experiments, analytical treatments, and Monte Carlo simulations of polymer chains confined in pores mimicking the basic premiss of the tube/reptation model are discussed. 

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