Poly(N-vinylcaprolactam) microgels.: Polymeric stabilization with poly(vinyl alcohol)

Poly(vinyl alcohol), PVA, with different molecular weights, M-w, and degrees of hydrolysis has been used to study the steric stabilization of microgels based on poly(N-vinylcaprolactam). The stabilizer influences the particle size and stability, but has no influence on the thermal properties. The thermal behavior of microgels depends on the heating rate: slow heating leads to the formation of aggregates and fast heating to an intramolecular collapse. The aggregates showed an unusual angular dependence of the diffusion coefficient, which can be explained by the presence of probably an additional rotational diffusion.