Any good master topics within sustainability and supply chain management. You are more than welcome to recommend research paper regarding sustainability and supply.
I shall start the ball rolling by posting my comment, which hopefully will bring in more responses. Rather than providing a link to an article, and there are many related to it (3D printing), but they are very technical, I shall set out my thoughts.
What about a challenging topic?
Why not examine how the arrival of 3D printing could affect supply chain? It is also known as additive manufacturing with 3D printing technology. I have many ideas but here is one for you to consider. Instead of shipping parts from the main or mother company to a subsidiary, one could have a 3D printer print out that part to reduce shipping costs, reduce lead time or waiting time, lower inventory holding costs, and minimize obsolescence cost, etc., and at the same time make a positive contribution to sustainability in some way by reducing or eliminating transportation costs.
Of course suitable printers should be available, with different printing materials like plastic, metals, etc. Today, a company has produced "3D printed tissues" for use in drugs testing – we can spare live animals the pain of being exposed to new medication under development in laboratories around the world. Why should animals suffer pain and die serving us – they are like us, are they not?
A recent development is Selective Laser Sintering, which broadens the possibilities considerably.
General Electric of the US, which also make jet engines in addition to things like turbines and locomotives, is using additive manufacturing to make jet engine parts -- there are few things more critical than jet engines reliable enough, to take an aircraft up and bring it down safely. GE has bought two companies for more than $1B so that it will be a leader in 3D printing technologies and products.
If you would like someone to co-guide you in your research, I am willing to consider that. Incidentally, I had previously taught courses in logistics and operations management, amongst other topics, at university here in The Netherlands... so I do have some ideas of supply chain. Further, I have also taught a in course environmental science...so sustainability is more than of passing interest to me.
Finally, a food for thought: a 3D printed bridge over a canal in Amsterdam is in the works and will be completed this year, 2017. As you are in Denmark, you might want to visit it and perhaps walk on it...to the other side of the canal in Achterbrugwal, Amsterdam, early next year.