Chain Propagation/Step Propagation Polymerization, III. An XPS (X-ray Photoelectron Spectroscopy) Investigation of Poly(oxyethylene)-b-Poly(pivalolactone) Telechelomer.

摘要

The)surface composition of polymer systems determine many polymer properties such as biocompatibility, catalysis, adhesion, and weathering. A number of techniques have been used to examine polymer surfaces, and of these, x-ray photoelectron spectroscopy (XPS, also called ESCA), has become a valuable tool. This technique is particularly suitable to look at depths of 30 A or less in organic polymers, and it is a nondestructive technique. A combination of chain and step propagations is being used to prepare a series of segmented copolymers containing polyoxyethylene and polypivalolactone segments each with narrow molecular weight distributions. The incompatibility of the two segments coupled with the difference in surface energies of the two segments could result in good phase separation with the polyoxyethylene segment thereby being found on the surface. Poly(oxyethylene)-co-(pivalolactone) telechelomer, which is the precursor to the segmented copolymer, is used as a model to develop an XPS method for surface analysis. An angular resolution study shows that negligible amounts of poly(pivalolactone) segments are present near the surface. Core level spectra of the telechelomer and its model compounds are presented to indicate that poly(oxyethelene) segment is richer near the surface. Keywords: Chelates; Reprints. (aw)