ε-Caprolactone as a medium for improving dispersability of graphene oxide in polyamide based composites

We described preparation of composites of graphene oxide with copolymers containing scaprolactam and c-caprolactone structural units. Graphene oxide was prepared using modified Hummers method and characterized by elemental analysis and X-ray photoelectron spectroscopy measurements, interlayer distance was evaluated from X-ray diffraction. Two types of copolymers - polyesteramides - with molar ratio of e-caprolactam to e-caprolactone units in polymerization feed 80/20 and 90/10 were prepared by polymerization casting method. Graphene oxide content in both types of polyesteramides was in range from 0.1 to 1 wt.%. Thermogravimetric analysis and differential scanning calorimetry were utilized to study thermal stability and crystallization behaviour of materials. Prepared composites were characterized by tensile modulus and impact strength. Rheological properties of polymer melts and viscometry of diluted polymer solutions revealed the physical character of polymer-filler interactions.