Rubbery Phases in Blends and Emulsions

The most comprehensive information on the phase structure and molecular mobility in polymer materials can be gained with high-resolution NMR techniques [17, 18, 30, 31, 34]. Low-resolution NMR techniques may offer some advantages in the following cases  

1) characterisation of phase structure and network density in polymers with a complex chemical composition that result in substantial overlapping of resonances from different chemical groups, hampering the interpretation of high-resolution NMR data, 

2) fast quantitative analysis of phase composition, phase transition and network structure, and 

3) when accurate control of sample temperature is required, which can be easily realised with the aid of low-field NMR equipment, allowing analysis of phase transitions. 

Analysis of XH T2 relaxation as a function of temperature yields information on molecular motions. Side-groups and local chain motions (secondary relaxations) cause a change in T2 below the Tg. The value of T2 increases with the amplitude and the frequency of molecular motions. The glass transition that occurs in the time scale in the NMR T2 relaxation 

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