Nanocomposites from phenolic resin and various organo-modified montmorillonites: Preparation and thermal stability

Phenolic resin (PF)/montmorillonite (MMT) nanocomposites have been successfully prepared using intercalative polymerization of resole-type phenolic resins in montmorillonites modified by octadecylamine (C18), benzyldimethylhexadecylammonium chloride (B2MH), benzyltriethylammonium chloride (B3E), and benzyldimethylphenylammonium chloride (B2MP). X-ray diffraction measurements and transmission electron microscope observations showed that clay platelets were partially exfoliated or intercalated after complete curing of the phenolic resins. The cured nanocomposites were named as modifier-MP (MP means montmorillonite-phenolic resin), for example, B3E-MP. Thermogravimetric analysis showed that thermal decomposition temperatures (T(d)s) of the cured nanocomposites B2MP-MP (826 K), B3E-MP (794 K), and B2MH-MP (783 K) were much higher than those of C18-MP (768 K) and cured phenolic resin (737 K). Therefore, thermal stability of the nanocomposites depends mainly on the chemical structure of the organic modifiers. B2MP-MP possesses the highest T-d since B2MP contains both benzyl and phenyl groups, followed with B3E-MP and B2MH-MP whose modifiers contain only one benzyl group. This is attributable to favorable interaction between phenolic resin and organic modifiers containing benzene rings. (c) 2006 Wiley Periodicals, Inc.