Complexation of Dodecyl-Substituted Poly(acrylate) by Linked β-Cyclodextrin Dimers and Trimers in Aqueous Solution

Two-dimensional NOESY H-1 NMR, isothermal titration calorimetric (ITC), and rheological studies of host-guest complexation by -cyclodextrin, -CD, and the -CD groups of the linked -CD dimers, -CD(2)ur and -CD(2)su and trimers, -CD(3)bz and -CDen(3)bz, of the dodecyl, C12, substituents of the 3.0% substituted poly(acrylate), PAAC12, in aqueous solution are reported. Complexations by -CD, -CD(2)ur, -CD(2)su, -CD(3)bz, and -CDen(3)bz of the C12 substituents of PAAC12 in 0.2 wt % solution exhibit complexation constants 10(-4)K(11) (298.2 K)=0.83, 5.80, 4.40, 15.0, and 1.50 dm(3) mol(-1), respectively. (The corresponding H-11 and TS11 show a linear relationship.) The rheologically determined zero-shear viscosities of 3.3 wt % aqueous solutions of PAAC12 alone and in the presence of -CD, -CD(2)ur, -CD(2)su, -CD(3)bz, and -CDen(3)bz (where the -CD groups and C12 substituents are equimolar) are 0.016, 0.03, 0.12, 0.25, 0.12, and 0.08 Pa s (298.2 K), respectively, and show PAAC12 to form interstrand cross-links through complexation. (c) 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 1278-1286