Intermacromolecular complexation because of specific interactions 11. Ionic interaction complexation and its comparison with hydrogen-bonding complexation Guangzhao Zhang a , Ming Jiang a, * , Lei Zhu a , Chi Wu b,c a Institute of Macromolecular Science and Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai 200433, People’s Republic of China b Chemistry Department, The Chinese University of Hong Kong, Shatin, Hong Kong, People’s Republic of China c The Open Laboratory of Bond-Selective Chemistry, Department of Chemical Physics, University of Science and Technology of China, Hefei, People’s Republic of China Received 19 October 1999; received in revised form 4 April 2000; accepted 24 April 2000 Abstract The ionic interaction complexation between metal carboxylated polystyrene ionomers and poly(butyl methacrylate-co-vinyl pyridine) (BVP) in both solution and bulk was studied by viscometry, laser light scattering (LLS) and differential scanning calorimetry (DSC) and compared with that between BVP and carboxylated polystyrene (CPS), in which the interacting groups are in acid form. The results show that both kinds of complexation strongly depend on the level of the specific interaction and give rise to an increased hydrodynamic radius over the component polymer coils. However, the ionic interaction complexation generally results in an increased viscosity in the solution and almost always exhibits two glass transition temperatures (T g s), in contrast, the hydrogen bonding complexation leads to a decreased viscosity and only one T g . The different behavior is attributed to the difference in spatial distributions of the interacting sites in the complexes.  2000 Elsevier Science Ltd. All rights reserved. Keywords: Intermolecular complex; Specific interactions; Ionomer 1. Introduction Intermacromolecular complexation between unlike chains through secondary bonding or specific interactions has aroused considerable interests experimentally and theo- retically for years [1–21], because of its significant impor- tance in understanding some biological processes and self- assembly of molecules, as well as in developing new func- tional assembled materials. The development made on H- bonding complexation in the last decade has been reviewed quite recently by Jiang et al. [1]. It has been demonstrated that H-bonding complexation in solution generally shows a decreased viscosity compared to the expected value by addi- tivity law and only one T g in bulk. By laser light scattering (LLS), we found that H-bonding complexation usually leads to an increase in hydrodynamic radius and narrowing in hydrodynamic radius distribution compared to the compo- nent polymer coils in solution [1–4]. On the other hand, in the literature, attention has also been paid to the inter- macromolecular complexation caused by the ionic inter- action [4]. The complexation of sulfonated random ionomers such as those based on poly(ethylene-co- propylene-co-ethylidiene nobornene) (SEPDM) [6–8] and poly(phenylene oxide) (SPPO) [9,10] and polystyr- ene (SPS) [9–11] with pyridine-containing random copolymer, i.e. poly(styrene-co-4-vinylpyridine) (SVP) in nonpolar and polar solvents were investigated by viscometry in several laboratories [6–11]. MacKnight et al. [12] assessed the complexation between SPS and poly(ethyl acrylate-co-4-vinylpyridine) (EVP) in solu- tion by means of the fluorescent probe technique. These studies reported that the ionic intercomponent complexation in bulk often show two glass transition temperatures (T g s) in bulk, and an increase in viscosity in solution. Similar behavior has been observed for the blends containing ionic interaction groups located at the chain ends exclusively leading to non-covalent block or graft architectures [13–19]. Our investigations on the blends of triblock ionomers based on poly(styrene-b-ethylene-co- butylene-b-styrene) (SEBS) and pyridine-unit-containing Polymer 42 (2001) 151–159 0032-3861/01/$ - see front matter  2000 Elsevier Science Ltd. All rights reserved. PII: S0032-3861(00)00332-3 * Corresponding author. Tel.: +86-21-6564-3919; fax: +86-21-6564- 0293. E-mail address: mjiang@fudan.edu.cn (M. Jiang). www.elsevier.nl/locate/polymer