The Properties of Glass Fiber Reinforced Polypropylene Filaments Recycled from Fishing Gear

Plastic pollution, mainly from lost fishing gear composed of high-density polyethylene (HDPE) and polypropylene (PP), poses a significant environmental obstacle. This study evaluates the potential of recycling PP from fishnet/rope and reinforcing it with glass fiber (GF) in the form of 3D printer filaments as a way to reduce/prevent ocean plastic. Two materials, one virgin (vPP-GF) and one made up of recycled polypropylene and virgin glass fibers (rPP-GF), were analyzed using differential scanning calorimetry, tensile, and Charpy impact tests. From the results, it was found that rPP-GF often outperformed vPP-GF. rPP-GF had a higher melting and crystallization point, likely a higher crystallinity, and could withstand a higher tensile stress, while vPP-GF could withstand a higher tensile strain. Further analysis revealed the potential presence of HDPE within the rPP-GF composite, which was not reported by the manufacturer. This significantly affected the Charpy test and made it difficult to draw conclusions from the resulting data. Nevertheless, their comparability in terms of mechanical and material properties indicates the strong potential of recycling polypropylene fishnet/rope and reinforcing it with glass fibers to extend their lifespan and reduce ocean plastic.