Improving the Mechanical Performance of LDPE/PP Blends through Microfibrillation

C. ROSALES; N. ARANBURU; I. OTAEGI; V. PETTARIN; C. BERNAL; A. MULLER; G. GUERRICA-ECHEVARRÍA

Applied Polymer Materials

American Chemical Society

Año: 2022

2637-6105

Polyolefins (polyethylene (PE) and polypropylene(PP)) are the most abundant polymers found in plastic solid waste.They are expensive to separate, and recycling them in the form ofblends is not viable due to their immiscibility and incompatibility.Following the idea of the circular economy where waste is turnedinto raw materials for manufacturing technological products usingminimum energy, a solution is proposed for the poor behavior ofimmiscible PE/PP blends by taking advantage of their immiscibilityto transform them into microfibrillar composites (MFCs). PE/PPblends with an 80:20 content ratio were studied, emulating theratio found in municipal waste. A microfibrillar structure wasachieved through an unusual combination of common industrial processing techniques: extrusion, drawing, and injection. Theperformance of the resulting fibrillar materials was evaluated by means of tensile, fracture, and impact tests, and the results werecompared with those of unstretched blends (UBs) with droplet morphology. The effect of adding a compatibilizer was alsoevaluated. The results were promising as the performance of the MFCs was much better than that of the nonfibrillated blends, and asynergistic effect between the addition of the compatibilizer and microfibrillation process was observed. It seems that this type ofprocessing has great potential for large-scale application in immiscible recycled polyolefin blends in which the final properties can beimproved by modifying their morphology, obviating the need to separate these polymers in mixed waste streams.