The cooperative diffusion coefficient Dcoop and the normalized variance /,/2 ~-2 for bimodal end-linked polydimethylsiloxane (PDMS) networks were determined by means of dynamic light scattering (DLS) measurements./)coop was proportional to polymer weight concentration at the equilibrium state of swelling Ce to the power of 0.88, which was larger than the theoretical exponent, compared with the unimodal PDMS networks. Further, the value of/~2r -2 at the lowest Ce was greater than that of the corresponding bimodal PDMS solutions in the semidilute regime, and the autocorrelation function of DLS could be reproduced by a double-exponential fitting. These facts suggested a spatially and compositionally heterogeneous structure of bimodal PDMS networks, especially in the case of the lowest C=.
Посилання на статтю:
Dynamic light scattering study on a bimodal end-linked polydimethylsiloxane network structure / Hidetoshi Oikawa // Polymer. – 1992. – Vol 33. – P. 1116-1119.