Synthesis and Characterization of a Polyurethane Phase Separated to Nano Size in Epoxy Polymer

¹ Korea Research Institute of Chemical Technology
² The Center for Chemical Industry Development, Korea Research Institute of Chemical Technology, 45, Jongga-ro, Yugok-dong, Jung-gu, Ulsan 44412, Korea

Published: 15 March 2019 by MDPI in 1st Coatings and Interfaces Web Conference session Surface Characterization

https://doi.org/10.3390/ciwc2019-06162

Abstract:

Epoxy resins are widely applicable in industries such as aircraft, automobiles, coatings, and adhesives because of their good chemical resistance and excellent mechanical and thermal properties. However, on an external impact, the crack propagation of epoxy polymers weakens the overall impact resistance of the materials. Therefore, many impact modifiers have been developed to reduce the brittleness of epoxy polymers. Polyurethanes as an impact modifier can improve the toughness of polymers. Although it is known that polyurethanes are phase-separated in the polymer matrix after curing, connecting polyurethanes to the polymer matrix has been problematic for enhancing the mechanical properties of polymers. In this study, we introduced epoxy functional groups into polyol backbones, which is different from other studies that focused on modifying capping agents to achieve a network structure between the polymer matrix and polyurethane. We confirmed the molecular weight of the prepared polyurethane with gel permeation chromatography. Moreover, the prepared material was added to the epoxies to evaluate the changes in the mechanical and thermal properties of the materials. Furthermore, we conducted tensile, flexural strength, and impact resistance measurements. The experimental results are discussed in detail.

Keywords: epoxy resin, polyurethane, physical properties

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Comments on this paper

MANAR Abdalrazeq

20 March 2019

Question

My question is there is another application for prepared material which is different from epoxy polymer, I mean there is a special properties or you in this study improved the epoxy polymer properties for the same applications?
Thank you

TAE HEE KIM

21 March 2019

Thank you for your question. We are interested in developing high performance of structural adhesives based on epoxy paste. For the purpose, I think that polyurethane plays an important role to enhance the impact strength of the paste.

Therefore, we have researched to develop new polyurethanes with strong toughness. I think that the product can be used in adhesive as well as other epoxy pastes for epoxy composites.

Silvia Fare'

27 March 2019

question on stability properties

Polyurethanes can be subjected to different degradation mechanisms. Did you take them into consideration? what about the possible degradation mechanisms of PU and their product release?

Henry Hitt

1 April 2019

it would be good to provide X-ray data of small-angle scattering

Information about the fragility of epoxy polymers has long been known! Numerous works on the development of impact modifiers to reduce the brittleness of epoxy polymers are also known.
It is also known that polyurethanes as a modifier of toughness can improve the toughness of polymers. Although it is known that polyurethanes are phase separated in the polymer matrix after curing, combining the polyurethanes with the polymer matrix was problematic to improve the mechanical properties of the polymers.
In the report, the authors introduced epoxy functional groups into the main chains of polyols, which is different from other studies, which focused on modifying closures to achieve a network structure between the polymer matrix and polyurethane.
To confirm the conclusions of the work, it would be good to provide X-ray data of small-angle scattering. This would help to say quite clearly about the interpenetration of the networks of polymers that were investigated.