Polyethylene glycol as an epoxy modifier with extremely high toughening effect: Formation of nanoblend morphology

Abstract

The brittle nature of epoxy polymers is one of their main drawbacks, preventing their widespread applications. In this research article, a new modifier with an extremely toughening effect on brittle epoxy was developed. It was found that introducing low-molecularweight polyethylene glycol (PEG) in the low amounts (up to 10%) into epoxy matrix considerably improves the impact and fracture properties of epoxy thermosetting polymer without attenuating its tensile properties. Epoxy/PEG hybrid containing 10% PEG exhibited an impact strength of 56.3 kJ/m 2 which is 5.7 times greater than that of pristine epoxy. The fracture strength of 7.7 MPa m 1/2 with 540% increase compared to pure epoxy was also observed for the hybrid material. Morphological, chemical, and thermal properties of epoxy/ PEG hybrid were studied using scanning electron microscopy, Fourier transform infrared spectrometry, and differential thermal analysis, respectively, to find out the basic reasons behind such a considerable improvement. A new morphology, consisting uniformly dispersed PEG nanoparticles in the epoxy matrix, was observed for the modified hybrid. This unique morphology for epoxy/PEG was named as nanoblend. The results showed that the formation of nanoblend morphology with strong interaction between epoxy and PEG in the blend structure is responsible for epoxy toughness.

Improved interfacial adhesion in carbon fiber/epoxy composites through a waterborne epoxy resin sizing agent

“…As for these PEG modified products, epoxy vibration peaks at 1250, 915, and 830 cm −1 reflect that the PEG2000‐HBPAE sizing is an epoxy compound. The absorption peak at 3500 cm −1 belongs to the stretching vibration of hydroxyl group . It indicates that PEG has copolymerized with the HBPAE.…”

“…As we know, as a popular material for modifying epoxy resins, polyethylene glycol (PEG) has a helical conformation along with a large amount of ether groups in its chain and two terminated hydroxyl groups, indicating a good compatibility with epoxy resin as well as outstanding hydrophilicity. Moreover, it should be noted that all PEGs have the advantage of environmental friendliness . Therefore, it is advisable and producible to prepare a series of PEG modified WEP sizing by adjusting molecular weight.…”

“…Previous research mainly concerned about the effects of dosage and formulation of PEG on the sizing emulsion stability and mechanical properties of CF/EP composites . Mahnam et al .…”

Graphene Oxide as a Prospective Graft in Polyethylene Glycol for Enhancing the Toughness of Epoxy Nanocomposites

“…PEG alone is able to modify the properties of epoxy at higher loadings only (10 wt%) . To the best of our knowledge, there are no reports in the literature regarding the use of nanofiller‐grafted PEG in enhancing the properties of epoxy matrix.…”

Innovative materials of this era for toughening the epoxy matrix: A review

“…These results suggest that the localization of PEO chains around the micelle core is an important design parameter. Zavareh and Samandari [181] recently reported a 2-to 3-fold increase in fracture toughness using a PEO modifier in epoxy at comparable concentrations. Even though a toughening mechanism was not suggested, the authors reported the formation of nano sized domains in the thermoset.…”