Synthesis of new graft copolymers containing polyisobutylene by a combination of the 1,1‐diphenylethylene technique and cationic polymerization

The synthesis of macroinitiators for the cationic polymerization of isobutylene via radical polymerization is presented. The 1,1‐diphenylethylene system was used to obtain macroinitiators consisting of 4‐chloromethylstyrene and methyl methacrylate units. The resulting polymers were used for the cationic polymerization of isobutylene, yielding graft copolymers that were characterized by gel permeation chromatography and NMR. The dependence of the molar mass and polydispersity on the temperature and monomer concentration was studied. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3725–3733, 2002     

The random contact point model for pair interaction coefficients of unlike solute molecules

The random contact point model described in previous papers is extended to include like-unlike pair interaction coefficients. On the basis of this extension we present the thermodynamics of group interactions involving alkyl, hydroxyl and amide (peptide) groups and water molecules. The values obtained for the Gibbs energy of group interaction (absolute values ranging from 1.5 to 9.8 kJ-mol^–1) indicate that all these groups attract or repel each other in aqueous solutions with comparable strength. Group interaction parameters obtained from aqueous and non-aqueous systems, and based on interaction coefficients and other thermodynamic quantities, agree well. The model also allows for the quantification, though not for the prediction, of the cooperativity of hydrophobic interaction.     

Generalized spherical functions on projectively flat manifolds

Local and global properties of the first order spherical functions are generalized to projectively flat manifolds.