Hardness and Chemorheological Properties of Chemically-Modified Polyfurfuryl Alcohol Resin Roghayyeh Marefat Seyedlar 1 , Mohammad Imani 1,2 , and Seyed Mojtaba Mirabedini 1,3(&) 1 Iran Polymer and Petrochemical Institute (IPPI), PO Box 14965-115, Tehran, Iran sm.mirabedini@ippi.ac.ir 2 Biobased Monomers and Polymers Division (BIOBASED Division), Iran Polymer and Petrochemical Institute (IPPI), PO Box 14965-115, Tehran, Iran 3 Color and Surface Coatings Department, Iran Polymer and Petrochemical Institute (IPPI), PO Box 14965-115, Tehran, Iran Abstract. Polyfurfuryl alcohol (PFA) is cured with amine-based curing agent via carbonyl functional groups of the resin. In this study, PFA was chemically modified via Deils-Alder reaction with different wt% of maleic anhydride (MA). Curing behavior of the modified resins was investigated in the presence of the polyamine curing agent using chemorheological and hardness techniques. According to the results, increasing MA wt% from 1 to 5, leads to increase of viscosity and storage modulus (G 0 ) of the mixture. However, the rate of vis- cosity increasing is higher than the increasing rate of G 0 for resins with higher MA content. In these systems, viscosity increases faster due to higher concen- tration of MA which results in reduction in chains mobility and crosslinking reaction which affects G 0 increasing rate. Hardness of the formulations increases with MA content and time progression up to 72 h. Keywords: Polyfurfuryl alcohol Á Chemical modification Á Diels alder Á Maleic anhydride Á Chemorheology 1 Introduction Polyfurfuryl alcohol (PFA) possesses a promising potential for industrial applications, especially where high thermal stability, smoke emission, residual char, chemical resis- tance against strong alkalis and acids are required with a relatively low cost [1]. Curing of the resin in the presence of acid catalysts occurs at high temperatures above 90 °C which limits its widespread commercial application [1]. To resolve the shortcoming, PFA is supposed to be cured using amine curing agents. However, the carbonyl functional group content of PFA resin is not adequate to react with amine curing agent. In this study, PFA resin was modified with maleic anhydride via Diels-Alder reaction to increase the C=O functional group content of the resin. Then, curing behavior of the modified resins in the presence of amine curing agents was studied via rheology and hardness techniques. © Springer Nature Switzerland AG 2020 H. Mirzadeh and A. A. Katbab (Eds.): ISPST 2018, Eco-friendly and Smart Polymer Systems, pp. 247–250, 2020. https://doi.org/10.1007/978-3-030-45085-4_59