The Effect of Different Compatibilizers on the Properties of a Post-Industrial PC/PET Blend

Abstract

The substitution of virgin resins by recycled ones is a worldwide tendency that is supported by the fluctuation of oil prices and the transition to a circular economy. Polymeric blends have been intensively studied because of their ability to provide tailored properties for particular applications. However, in their design phases, the issue of end-life re-use had not been well addressed, and now difficulties in their recycling are arising. In this study, we investigated the effect of three different compatibilizers: two chain extenders (CEs), (1) a styrene-acrylic oligomer (ESAo), and (2) methylene diphenyl diisocyanate (MDI) and an impact strength modifier, (3) an ethylene copolymer (EMAco), for the recycle of a post-industrial polycarbonate/polyethylene terephthalate (PC/PET) blend. The materials were prepared by reactive extrusion and characterized by intrinsic viscosity (IV) measurements, mechanical tests, differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy analysis (FTIR), and transmission electron microscopy (TEM). The introduction of each additive has been demonstrated to improve the compatibility between PET and PC in the post-industrial blend, leading to enhanced mechanical properties. The IV measurements increased to values that were comparable to the virgin material. In addition, CEs affected the crystallization of PET (as they reduced the degree of crystallinity), while EMAco acted as a nucleating agent. Morphological analysis enabled confirming the compatibilization effects induced by the tested additives.

Analysis of Thermomechanical Properties of Selected Class of Recycled Thermoplastic Materials Based on Their Applications

“…Also, as a side effect to consider, contamination by residues such as inorganic, organic, or biological residues cause deterioration of the polymers during recycling. Besides, the mechanical recycling of polymers introduces further problems owing to the complexity of the morphological structures that occur between the polymeric components [3,[31][32][33]. Based on the various mechanisms involved in the life cycle of polymers, the changes significantly alter the mechanisms of stabilization, mechanical, thermal, and rheological properties of recycled polymers [14,33,34].…”

“…Besides, the mechanical recycling of polymers introduces further problems owing to the complexity of the morphological structures that occur between the polymeric components [3,[31][32][33]. Based on the various mechanisms involved in the life cycle of polymers, the changes significantly alter the mechanisms of stabilization, mechanical, thermal, and rheological properties of recycled polymers [14,33,34]. The thermoplastic nature of these recycled thermoplastics raises essential questions about mechanical performance at high temperatures and low strain rates [35].…”

Compatibility and toughening mechanism of poly(ethylene terephthalate)/polycarbonate blends

“…Overall, compared with work reported in the literature on PET/PC blends, [20][21][22][23] the PET/PC/CP system developed in this work was significantly advantageous in toughness and optical transparency of the blends, as shown in Table 1, which shows the potential application in the field of soft-drink beverage bottles, packaging films and so on.…”

“…19 Some studies have reported the compatibilizing and toughening of PET/PC blends. [20][21][22][23][24] Jamaludin et al investigated the effect of the content of maleic anhydride grafted styrene-ethylene-butylene-styrene (SEBS-g-MA) on the mechanical, thermal and morphological properties of PET/PC/HNTs (halloysite nanotubes) nanocomposites. It was found that a maximum improvement in impact strength as high as 245% was achieved by incorporation of 10 phr SEBS-g-MA into the nanocomposites, and SEM analysis revealed a transition from brittle fracture to ductile fracture morphology with increasing content of SEBS-g-MA.…”

“…A maximum improvement in the impact strength as high as 280% was achieved by the incorporation of 10 wt% EMAco into the blends. 23 Habibelahi et al developed a new strategy to enhance the miscibility of PC and PET with the addition of PC/PET copolymer using reactive melt blending. The results indicated that the addition of PC/PET copolymers promoted the T g of the blend components to approach each other, and smaller PET particles formed and were uniformly dispersed in the PC matrix.…”