Six diblock copoly(oxybutylene/oxyethylene)s (Eg2B7, E50B73, E4, B, , E50B4, E24B10 and E27B5, where E represents oxyethylene and B represents oxybutylene) have been prepared by sequential anionic copolymerisation and their micellisation in aqueous solution investigated. Surface tension, static and dynamic light scattering and gel permeation chromatography techniques were used to study solutions at temperatures in the range 20 to 50°C over a wide concentration range from dilute to 100 g dm-3. The micellar properties reported are critical micelle concentrations, micellar molar masses and radii. The thermodynamics of micellisation of E , B , diblock copolymers is discussed in relation to that of related triblock copolymers ( E, , . , B, E, and E , P , E , , where P represents oxypropylene).

The gelation of concentrated aqueous micellar solutions of three diblock copoly(oxybutylene/oxyethylene)s

M 13 9PL , UK Oxyethylene/oxypropylene block copolymers were prepared with almost identical overall compositions (40 wt.% E) and molecular weights (M, = 2900) but different block structures, i.e. diblock E2,P2, and triblock E,4P30E,4. Their micellar and surface properties were studied by static and dynamic light scattering and surface tension. At a given temperature, the surface acitivity, the c.m.c., the molar micellar weight and the micellar size did not differ within the uncertainties of their determination. The only significant difference was in the area per molecule in the surface monolayer, wherein the diblock copolymer was more closely packed than the triblock copolymer.

The crystallinities of uniform a-hydro-w-hydroxytri(myalky1ene)s HO+(CH2),0-f3H with x = 3 to 6, were investigated by small-angle X-ray diffraction, low-frequency Raman spectroscopy, infra-red spectroscopy and differential scanning calorimetry. It is shown that the C, to C, trimers adopt a trans-planar conformation in their layer crystals, whereas the C, trimer adopts a different chain conformation. In all cases the hydroxy end groups are extensively hydrogen bonded.

Methods for the preparation and purification of uniform tri(oxyalky1ene)s from the C, to C, alkanediols are described. The preparation of the pure C, trimer [a-hydro-w-hydroxy-tri(oxytrimethylene)] is reported for the first time.