MONTMORILLONITE INTERCALATION COMPLEXES AND THEIR INTERACTION WITH EPOXY COMPOUNDS G. I. Gurina and K. V. Savchenko UDC 541.6+541.12+678.6 The formation of amine-intercaiated phases of montmoriUonite was determined using x-ray diffraction analy- sis, differential thermal analysis (DTA), and IR spectroscopy. The mechanism of interaction of epoxy and intercalation compounds was examined for the case of Pb~(C2H7NO) 2 and montmorillonite with amines. It was determined that intercalation complexes can be used as latent hardening agents and hardening accelera- tors for epoxy resins. Many compounds of layered structure are able to react with strong Lewis bases with formation of intercalated phases [1-5] characterized by definite stoichiometry if the concentration of the intercalant exceeds the thermodynamic concentration threshold [3]. The purpose of the investigation was a study of the possibility of using intercalation compounds as latent hardening agents and hardening accelerators for epoxy resins. At present, there are no published data about such use of intercalation complexes. The matrix of layered structure for the investigations was montmorillonite of composition (Mont) = (Nao.26 Cao.o6 ) (A11.73 Mgo.24 Feo.o3 ) Si4Olo (OH)o H20. The composition was determined with a flame photometer and an x-ray probe microanalyzer (MAP-4). As in [6], the basal interplanar spacing of the montmorillonite was 12.19 A. The amine-intercalated complexes were synthesized by the method of [1] by keeping the montmorillonite in a medium of amines for 48-96 h. The amines were aliphatic 1,6-hexanediamine (HDA) HeN(CH2)6NH 2 and aromatic amines 2,4,6- tris(dimethylaminomethyl)phenol (UP-606/2) [(CH3)eNCH2]3C6H2OH and 1 4-phenylenediamine (PDA) C6H4(NHe)2, used for hardening of epoxy resins. X-ray diffraction analysis (DRON-3) of the synthesized compounds revealed an increase of the basal interplanar spacing of the montmorillonite, e.g., by 7.11 A for the complex with UP-606/2 and by 5.81 A for the complex with HDA, which is a characteristic of the formation of intercalation complexes [1-5]. Their formation was also monitored according to IR-spectroscopic data. Thus, after intercalation, bands at 3330, 1630, 826, and 800 cm- 1 of vibrations of NH 2 groups of 1,6- hexanediamine were shifted to 3324, 1615, 815 and 789 cm -I, respectively. After intercalation, absorption bands of ~,(A1-O) = 915 and 722 cm -~ were shifted to 910 cm -1 and 718 cm-1; for example, bands of u(Si-O) = 1050, 522, and 463 cm -1 were shifted to 1030, 513, and 456 cm -1, respectively, for (Mont) (HDA)I.9. Such changes of the absorption bands of functional groups of other intercalants were also detected and confirm the participation of amines in charge-transfer donor-acceptor interaction (between the unshared electron pair of nitrogen atoms and the coordination-unsaturated atoms of the inorganic matrix) [71. The stoichiometric coefficients x and the maximum temperatures of deintercalation were determined according to data of thermal analysis for (Mont)(Amine)x intercalation complexes: 458, 423, and 383 K for (Mont) (HDA)I.9_+o.2, (Mont) (UP- 606/2)1.2+o.2, and (Mont) (PDA)2.o_+o.2, respectively. The synthesized complexes were introduced into the composition of epoxy composites. Epoxy resins I~D-20 (epoxy group (EG) content = 19%), t~-41 (EG = 8%), and t~-49 (EG = 6%) were chosed for the composites. Kharkov Polytechnic Institute. Translated from Teoreticheskaya i t~ksperimental'naya Khimiya, Vol. 29, No. 1, pp. 88-91, January-February, 1993. Original article submitted March 18, 1993. 0040-5760/93/2901-0063512.50 9 Plenum Publishing Corporation 63