Open Access

ARTICLE

Toughening of Unsaturated Polyester Resin by Blending with Polyether Telechelics. Dependency of Toughening Efficacy on End Groups

by Jeemol. P. A¹, Mathew Suresh¹, Reghunadhan Nair C.P.^2,*

1 School of Chemical Sciences, Mahatma Gandhi University, Kottayam-686560, Kerala, India.
2 Polymer Science and Rubber Technology, Cochin University of Science and Technology, Cochin-682022, Kerala, India.

* Corresponding Author: e-mail:

Journal of Polymer Materials 2022, 39(1-2), 111-120. https://doi.org/10.32381/JPM.2022.39.1-2.7

Abstract

Polyether telechelics based on ethylene glycol,1,2-propylene glycol and 1,4- butylene glycol of with various molar masses and bearing at both terminals functional groups such as maleimide, itaconimide, nadimide and hydroxyl groups were individually examined as toughening agents for an unsaturated polyester resin (UPER). For a given telechelic, the toughening effect was evaluated at different mass ratios. The difference in toughening efficacy arose from the differential reactivity of the telechelics end groups combined with the unsaturation of the UPER with the reactive diluent, styrene. This causes a differential distribution of the polyether groups in the UPER matrices, resulting in a differential dipolar interaction of the polyether segments among themselves and with the UPER itself. The matrices cohesive strength is decided by these interactions, the possibility for which is decided by the spacing of these polyether segments in the matrix, as per the reactivity ratios between styrene-maleic complex pair and the polyether end groups. An increased inter-segmental spacing of polyether could diminish the chance for inter-segmental dipolar interactions that can stake the cohesive strength and thus the mechanical properties of the matrices. These aspects have been quantified in terms of their efficacy factors which conformed well to the strength and fracture properties of UPER blended in small proportions with the end-functionalized polyether telechelics.

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