Synthesis of core-shell polyurethane-polydimethylsiloxane particles by polyaddition in organic dispersant media: Mechanism of particle formation
Résumé
Core-shell polyurethane (PUR)-polydimethylsiloxane (PDMS) particles were prepared by polyaddition between ethylene glycol and tolylene-2,4-diisocyanate in cyclohexane, used as the organic dispersant phase, in the presence of reactive hydroxy-terminated polydimethylsiloxane steric stabilizers. The reaction extent and the PUR particle size, monitored by FTIR, H-1 NMR, SEC, SEM and TEM techniques against time, were found a function of the PDMS concentration, functionality and molar mass. A mechanism of the polyurethane particle growth is proposed on the grounds of the kinetic investigation.