Polyethylene is one of the most common materials in our daily lives and accounts for 40% of the total volume of world production of plastic materials. It is used in a large variety of products from plastic bags to medical implants. The annual world production is a staggering 120 million tons. Its production is highly reliant on ethylene gas from petrochemical resources. Moreover it is non degradable, which causes severe problems in the (marine) environment.Catylene aims at addressing both issues by developing alternative polyethylene-like materials from bio-derived macrolactones. These polymers resemble properties of polyethylene and are potentially degradable under environmental conditions. Recent breakthrough technology developed at TU Eindhoven will be exploited in this project, which is the first efficient organometallic catalyst for the polymerisation of macrolatones and the ability to process the polymers into applicable devices like fibres.In this project the up-to-now unknown underlying mechanism of the organometallic polymerisation of macrolactones will be investigated and used for the rational design of more sophisticated catalysts. The knowledge will be applied to obtain polyethylene-like polymers with build-in degradability for applications ranging from simple plastic goods to biomedical materials. This will be done combining expertise and training in catalysis, biotechnology, polymer chemistry, material science and life cycle analysis in collaboration with SABIC Europe. Successes will open opportunities to green polyethylene-like polymers with reduced environmental impact.