Preparation, structure and thermomechanical properties of nylon-6 nanocomposites with lamella-type and fiber-type sepiolite

Nylon-6 nanocomposites filled with lamella-type and fiber-type sepiolite were prepared by the simple melt-compounding approach and compared with the common nylon-6/montmorillonite (MMT) nanocomposite. Morphology and dispersion state of fillers were observed by scanning and transmission electron microscopy. Wide-angle X-ray diffraction and differential scanning calorimetry analyses were carried out to investigate the crystallization behaviors of nanocomposites. The results suggested that sepiolite facilitates the formation of α-phase crystals of nylon-6, which is quite different from the case observed in MMT-filled nanocomposites. Thermomechanical tests showed that heat distortion temperature and Young’s modulus of sepiolite-filled nanocomposites are obviously improved compared with neat nylon-6. Interestingly, sepiolite-filled nanocomposites exhibited the highest level of reinforcement on the Young’s modulus, which may stem from the more efficient interfacial stress transfer. In addition, tensile fracture morphologies of nanocomposites filled with sepiolite and MMT are also compared.