Patent ID: 9469742
Filing Date: 2016-10-18
CPC Classification: C08K,C09K,H01B

Claim Text:
1. A method for producing polyamide composites containing graphene, comprising the following steps: (i) dispersing a graphitic or graphenic material in an aqueous medium to yield an exfoliated material, and optionally removing non-reacted starting material from the aqueous mixture; (ii) mixing at least one lactam monomer with the aqueous mixture obtained in step (i); (iii) adding at least one non-ionic surfactant to the aqueous mixture obtained in step (ii); (iv) removing from the aqueous mixture obtained in step (iii) essentially all water contained therein; (v) heating the mixture obtained in step (iv) to 100 to 200° C.; (vi) if the water content of the mixture obtained in step (v) is higher than 300 ppm, subjecting the mixture obtained in step (v) to a further drying process to obtain a mixture with a water content of at most 300 ppm; (vii) heating the mixture obtained in step (v) or (vi) to 100 to 200° C.; (viii) adding an anionic polymerization activator; (ix) adding an anionic polymerization catalyst; and (x) after polymerization is completed, isolating the resulting polyamide composite; where the graphitic or graphenic material used in step (i) and the at least one non-ionic surfactant added in step (iii) are used in a weight ratio of from 20:1 to 1:1.