The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The dynamics of chain exchange between flowing bulk melt and the channel wall were studied for oligomeric polyolefins using attenuated total reflectance Fourier transform infrared spectroscopy (ATR/FTIR). The dynamics are dominated by a surprisingly slow first-order process which depends on flow rate and materials of construction of the channel wall. The picture which seems to emerge is an entropically-driven flow-rate-(or stress-) dependent adsorption equilibrium which retards the exchange between the surface and bulk.