Properties of mechanically recycled polycaprolactone-based thermoplastic polyurethane/polycaprolactone blends and their nanocomposites

Abstract

In this study, the effect of mechanical recycling process parameters on the morphology, properties, and hydrolytic degradation of polycaprolactone-based thermoplastic polyurethane/polycaprolactone waste blends (TPU-PCL/PCL) and their nanocomposites were investigated. Modification of recycled TPU-PCL/PCL was carried out using natural and organically modified montmorillonite nanoclays. Effect of reprocessing time on the structure of TPU-PCL/PCL and nanoclay separation in nanocomposites was evaluated by differential scanning calorimetry, Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy analysis. It has been demonstrated that mechanical recycling of waste from industrial TPU-PCL/PCL only marginally changes its properties. The exfoliation of Cloisite 30B clay was not enough to enhance the properties of recycled materials. However, the structure, thermal, and mechanical properties, hydrolytic degradation of obtained recycled TPU-PCL/PCL:nanoclay nanocomposites depend on the separation level of the nanoclays.

End-of-Life Options for (Bio)degradable Polymers in the Circular Economy

“…This work showed that the additive in nanocomposites slightly reduces the tensile strength and elongation at break of recycled thermoplastic polyurethane/PCL blends. Moreover, the influence of additive on hydrolytic degradation, elastic modulus, and melt flow index properties was observed [49].…”

Recycling of polyurethanes: where we are and where we are going

“…Since, by definition, thermoplastic polyurethanes (TPUs) can be melted, they can be mechanically recycled using the common method employed for thermoplastic polymers in general, i.e., by extruding the recycled materials in the form of flakes or pellets, in the presence of some virgin polymers and/ or compatibilizers. [14][15][16][17] Conversely, thermosetting PUs, at least highly crosslinked PUs such as foams, cannot be recycled in such way, but what is generally called "physical recycling" is the eligible method. Physical recycling implies the direct reuse polyurethane wastes, still in form of powders, flakes or small particles without chemical treatment, 11 and thus it can be considered among the secondary recycling methods.…”

Thermoplastic Elastomers Containing Zinc Oxide as Antimicrobial Additive Under Thermal Accelerated Ageing

“…The spectrum depicts bands typically from TPE based on SEBS/PP/oil/calcite, such as the peaks at 2952 cm -1 , 1493 cm -1 , 757 cm -1 and 698 cm -1 that are common in aromatic compounds, the peaks at 2920 and 2852 cm -1 attributed to C-H vibrations. Also, bands were found at 1455 and 1377 cm -1 corresponding to methyl group and at 876 cm -1 which represents carbonyl group from CaCO 3 [23][24][25][26][27] . There were no differences in the FTIR-ATR profiles between aged and unaged compounds.…”