New organic-inorganic hybrids as multifunctional additives to improve ethylene-norbornene (EN) composite stability

In this study, new multifunctional organic-inorganic pigments were synthesized by the complexation of carboxlic azo dyes (D1, D2) with aluminum-magnesium hydroxycarbonate (LH) and were applied as colorants in ethylene-norbornene copolymer (EN). The structures of the hybrid pigments were analyzed by X-ray diffraction (XRD), secondary ion mass spectrometry (TOF-SIMS), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). X-ray diffraction revealed that the hybrid pigments had developed new crystalline structures and showed the presence of additional peaks on their diffraction patterns. Moreover, TOF-SIMS confirmed that the modification had been successful, with the formation of dye-metal complexes embedded in the LH structure. The EN composites with hybrid pigments were subjected to accelerated UV aging. Alterations were monitored by Fourier transform infrared spectroscopy (FT-IR), spectrophotometry, differential scanning calorimetry (DSC) and mechanical tests. It was found that the EN composites containing hybrid pigments showed approximately 4 times higher tensile strength than both EN and an EN sample with unmodified LH under 250 h of UV irradiation. Adding 2 wt % of the multifunctional hybrid pigments to EN copolymer significantly enhanced the aging resistance and thermal stability of the resulting composites. (C) 2018 Elsevier Ltd. All rights reserved.