Thermal and mechanical properties of polyamide 12/modified carbon nanotubes composites prepared via the in situ ring-opening polymerization

In this study polyamide 12 (PA12) based composites prepared in situ via an ring-opening polymerization of lauryl lactam in the presence of raw and functionalized carbon nanotubes (CNTs) are characterized. This method has been widely applied for thermoplastic based composites, resulting in materials with relatively small amounts and uniform nanofiller distribution. The effect of multi-wall carbon nanotubes chemically modified with hydroxyl or amine groups on PA12 matrix is discussed in terms of the phase structure, thermal, mechanical, and water vapor barrier properties as well as the state of CNTs dispersion in composites. The obtained results confirm, that in general the physical properties of PA12 are noticeably affected by the presence of 0.35 wt % CNTs, whilst the benefits from nanotubes modification are observed in changes of phase transition temperatures and composite mechanical performance, whilst the thermooxidative stability and water absorption the CNTs chemical modification is less pronounced.