Recycling decommissioned polyamide 11: An approach to handle a previously unwanted material

Polyamide 11 (PA11) is a polymer used in flexible lines for oil prospection due to its properties. After the decommissioning of the lines, the materials used are discarded in landfills or left in the ocean. As developing a sustainable economy is of utmost importance, reusing these discarded materials would be a step in the right direction. This research focused on examining two kinds of PA11 previously used in flexible lines to see their properties changed compared to virgin PA11 and to infer if they can still be reused. Chemical, thermal, and mechanical analysis were employed to analyze the PA11 that came from the two oilfields and recycled ones that were hot pressed with an unused PA11 in a 50/50 wt% proportion. Results indicate that one of the oilfield samples was less degraded than the other one, which provided better mechanical properties, and the same pattern happened with the recycled samples, indicating that some properties such as viscosity, plasticizer content, and crystallinity need to be evaluated before taking in consideration the reuse (be it recycling or repurposing) of this type of polymers in consideration. Two samples of PA11 that came from two different decommissioned flexible lines are tested and recycled with pure PA11 to see if they could still be used in technological applications. This analysis indicates that one of the samples showed suitable properties, indicating that it is important to analyze the degree of degradation of the PA11 before reusing.