Graphene reinforced polyethylene terephthalate
View Patent ↗A composition and a method are provided for graphene reinforced polyethylene terephthalate (PET). Graphene nanoplatelets (GNPs) comprising multi-layer graphene are used to reinforce PET, thereby improving the properties of PET for various new applications. Master-batches comprising polyethylene terephthalate with dispersed graphene nanoplatelets are obtained by way of compounding. The master-batches are used to form PET-GNP nanocomposites at weight fractions ranging between 0.5% and 15%. In some embodiments, PET and GNPs are melt compounded by way of twin-screw extrusion. In some embodiments, ultrasound is coupled with a twin-screw extruder so as to assist with melt compounding. In some embodiments, the PET-GNP nanocomposites are prepared by way of high-speed injection molding. The PET-GNP nanocomposites are compared by way of their mechanical, thermal, and rheological properties so as to contrast different compounding processes.
1. A method of preparing injected molded polyethylene terephthalate graphene nanoplatelet nanocomposites, comprising:
compounding polyethylene terephthalate with dispersed graphene nanoplatelets so as to obtain one or more master-batch pellets using twin-screw extrusion and ultrasound-assisted extrusion;
wherein the ultrasound-assisted extrusion comprises applying ultrasound waves to the polyethylene terephthalate and graphene nanoplatelets so as to increase the melt temperature locally as a result of acoustic cavitation, the ultrasound waves comprising ultrasound amplitudes of 5 μm; and
injection molding the master-batch pellets using a high-speed injection molding process to form polyethylene terephthalate-graphene nanoplatelet nanocomposites, wherein the polyethylene terephthalate-graphene nanoplatelet nancomposites comprise graphene nanoplatelets weight fraction ranging between 0.5% and 15%.
2. The method of claim 1 , wherein the ultrasound waves comprise ultrasound amplitudes of 7.5 μm.
3. The method of claim 1 , wherein the weight fractions result in an improvement in Young's modulus, while not affecting the strength of the polyethylene terephthalate.
4. The method of claim 1 , wherein the ultrasound-assisted extrusion increases toughness of the polyethylene terephthalate with no effect on Young's modulus.
5. The method of claim 1 , wherein the twin-screw extrusion is performed by an extruder comprising co-rotating screws.
6. An injection molded composition, comprising: master-batch pellets comprising polyethylene terephthalate and graphene nanoplatelet are melt compounded using a combination of twin-screw and ultrasound-assisted compounding techniques;
wherein the ultrasound-assisted compounding technique comprises applying ultrasound waves to the polyethylene terephthalate and graphene nanoplatelets so as to increase the melt temperature locally as a result of acoustic cavitation;
the ultrasound waves comprise ultrasound amplitudes of 5 μm; and
forming the injection molded composition by injection molding the compounded pellets by using a high-speed injection molding process, wherein the injection molded composition comprises graphene nanoplatelets weight fractions ranging between 0.5% and 15%.
7. The composition of claim 6 , wherein the ultrasound waves comprise ultrasound amplitudes of 7.5 μm.
8. The composition of claim 6 , wherein the weight fractions result in an improvement in Young's modulus, while not affecting the strength of the polyethylene terephthalate.
9. The composition of claim 6 , wherein the ultrasound-assisted extrusion increases toughness of the polyethylene terephthalate with no effect on Young's modulus.
10. The composition of claim 6 , wherein the twin-screw extrusion is performed by an extruder comprising co-rotating screws.