Self‐healing polymer blend based onPETGandEMAA

Abstract

In this work, novel immiscible polymer blends with remarkable self-healing properties were developed. The blends are based on poly(ethylene glycol-cocyclohexane-1,4-dimethanol terephthalate) (PETG), a nonself-healing polymer, and the ionomer sodium-neutralized poly(ethylene-co-methacrylic acid) (EMAA), with self-healing abilities. The ratios of (PETG)/ (EMAA) was varied from 0 to 100% (w/w) and mixtures were prepared using a twin-screw melt extrusion. The blend studied compositions were characterized by scanning electron microscope, differential scanning calorimetry, dynamic mechanical analysis and self-repair tests. The results revealed that blends samples were able to self-repair damages created by Vickers microhardness indentations. The self-repair is presented through video records where the establishment of scars in the damaged area can be observed. For the composition 50/50 (w/w), the whole repair was observed due the synergic effect between polymer chain mobility, new chemical interactions promoted between PETG and EMAA, thus improving its self-healing ability.

3Dprintability of highly ductile poly(ethylene glycol‐co‐cyclohexane‐1,4‐dimethanol terephthalate)‐EMAAblends

“…As the shear increase, these new bonds are undone and the result is the reduction of viscosity. [ 25,36,37 ] Figure 4 shows a schematic depicting the clusters of EMAA, detached by dotted reds circles. In case of FFF part layers, we speculate that this phenomenon could improve the adhesion between printing parts.…”

“…Accordingly, for these PETG/EMAA blends, the carboxyl groups (COOH) and Na + cations, from EMAA can establish strong interactions with COOH groups, from PETG, through Coulombian forces and hydrogen bonds. [ 25,36,49 ] It is known that ionic interactions can influence the relaxation and viscoelasticity of ionomers based on entangled chains by enhancing elastic mechanisms that come from crosslinked ions clusters physically bonded, therefore, increasing G'(ω). [ 45,50 ] Figure 6 presents the storage modulus, G'(ω), and loss modulus, G" (ω), at 230 °C (printing temperature) versus oscillatory frequency.…”

“…Smart materials with new properties, like self‐healing, self‐assembly, and shape‐memory have been also tested in 3D printing. [ 17,18,21,23–25 ]…”

“…In this context, blending PETG with ionomers could be a promising approach to improve its printability. The ionomeric interactions involving clusters of ionomers [ 25–27 ] could enhance the adhesion between the printed layers, thus improving the quality of the final products. Many works have pointed out the remarkable properties of ionomeric materials, such as high ductility, [ 27 ] compatibilization capabilities, [ 25,28–30 ] and even self‐healing.…”

“…The ionomeric interactions involving clusters of ionomers [ 25–27 ] could enhance the adhesion between the printed layers, thus improving the quality of the final products. Many works have pointed out the remarkable properties of ionomeric materials, such as high ductility, [ 27 ] compatibilization capabilities, [ 25,28–30 ] and even self‐healing. [ 25,31 ] For example, Zhao et al [ 26 ] employed ionomers in 3D FFF printing to obtain shape‐memory pieces.…”