ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Vanillin-derived epoxy monomer for synthesis of bio-based epoxy thermosets: effect of functionality on thermal, mechanical, chemical and structural properties

Mohsen Mogheiseh, Ramin Karimian, and Mostafa Khoshsefat

Chemical Injuries Research Center, Systems Biology and Poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran

E-mail: karimian.r@gmail.com

Received: 28 February 2020  Accepted: 13 April 2020

Abstract:

Abstract

Tri-functional vanillin-derived epoxy monomer was developed through the synthesized di-functional reagent and cured with a series of different types of hardeners (hydroxyl and amine based) to evaluate thermo-mechanical properties of the resultant epoxy thermosets. Through elevating of curing degree by the hardeners, both alpha transition temperature (T_α) and cross-linking density (υ) slightly increased (up to 118 °C and 69.9 mol m⁻³). However, the highest values of storage and loss modulus (E′ and E″, respectively) were obtained using trimethylolpropane (TMP) in epoxy thermoset systems cooperating with tri-functional epoxy monomer at 3200 MPa and 359.3 MPa, respectively. The sample produced by TMP exhibited the highest amount of statistic heat-resistant index (T_s) (up to 193 °C). Nevertheless, the longest half-life and the highest T_d are obtained for the sample prepared by incorporation of tris(hydroxymethyl)aminomethane (TRIS) and 1,10-diaminodecane (1347 s, 431 °C, respectively) containing amine agents as curing agent. Remarkably, the sample comprising triethanol amine showed the highest char yield (3.3 mg at 700 °C) among the all samples. However, the sample cured by TRIS exhibited the highest elasticity, elongation and tensile strength among the obtained samples (up to 0.48 GPa, 6.56% and 22.90 MPa, respectively).

Graphic abstract

Keywords: Epoxy thermoset; Bio based; Thermo-mechanical properties; Thermal stability; Vanillin; Oximation

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-020-01164-8

Chemical Papers 74 (10) 3347–3358 (2020)