Nylon 6/SiO2Nanocomposites Synthesized by in situAnionic Polymerization
2006; SAGE Publishing; Volume: 18; Issue: 3 Linguagem: Inglês
10.1177/0954008306063392
ISSN1361-6412
Autores Tópico(s)Silicone and Siloxane Chemistry
ResumoIn situ anionic polymerization of °-caprolactam in the presence of SiO 2 and silanated SiO 2 nanoparticles was promoted as a route for the synthesis of two series of nylon 6/SiO 2 nanocomposites. The process was performed at 160°C well below the melting temperature of the nylon 6 ( T m ~ 225 ° C) and initiated/activated with sodium dicaprolactamato-bis(2-methoxyethoxo)aluminate/ N, N′[methylene-di(4,4′phenylene)bis-carbamoyl]bis- δ-caprolactam system. The nanocomposites obtained exhibit higher onset decomposition temperatures than neat nylon 6 and a tendency of reduction of the polymer yields, degree of polymerization, water absorption and melting temperatures with silica content increasing. The crystallization temperature, T c of the nanocomposites reaches a maximum value at 2.0 wt.% of the nanoparticles. The mechanical tests of nanocomposites revealed an increase in flexural modulus as a function of filler percentage and a decrease in notched impact strength by addition of the modified silica (over 4.0 wt.%) and unmodified silica. Furthermore, the flexural strength diminishes both the treated and untreated filler content is increased for concentration of ~ 4.0 wt.%
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