Amphiphilic Graft Copolymers of VCL

Microcalorimetric endotherms recorded for solutions of PVCL and the PEO-grafted PVCL copolymers are broad, and markedly asymmetric, with a sharp increase of heat capacity on the low temperature side (onset of the transition, T em) and a more gradual decrease of the heat capacity as the tern- 

Turning our attention first to the endotherms recorded for PVCL (Fig. 21), we note that the onset temperature of the transition, Tdem and the temperature of the transition, Tmax. depend on the molar mass of the polymer Tdem decreases with increasing molar mass. The heat of the transition, however, does not depend on the molar mass of the PVCL chain, AH = 4.4 0.4 kJ mol [ 182]. The introduction of amphiphilic grafts along a PVCL chain shifts Tdem and Tmax to higher temperature, compared with the temperatures 

Sample Solvent VCL (mol 1, ) Initiator (mmol 1, ) Temperature (°C) Reaction time (h) Mw Polydispersity index  

Measured by static light scattering Measured by size-exclusion chromatography 

Additional information on the solvation layer around the polymers was obtained by PPC (Sect. 2.1), a technique that allows one to evaluate the changes in the partial volume of the polymer throughout the phase transition, and to obtain information on the temperature-dependant relative hydrophilicity/hydrophobicity of a polymer in solution [210]. Particular interest in the PPC studies was focused on the effect of the amphiphilic grafts on the volumetric properties of the polymers. 

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