Influence of the black seed oil modified epoxy resin/biscycloaliphatic epoxide monomer weight ratio on thermal properties of photocrosslinked coatings

The influence of the black seed oil modified epoxy resin (EBSO)/monomer 3,4-epoxycyclohexylmethyl 3,4- epoxycyclohexane carboxylate (BCDE) weight ratio in the coatings based on the compounds and photoinitiator triarylsulfonium hexafluoroantimonate (TAS) on thermal properties of photocrosslinked coatings have been studied. The chemical structure of investigated UV-cured coatings was characterized by IR spectrometric analysis. Their thermogravimetric (TG) and differential scanning calorimetry (DSC) behavior were determined by TG and DSC analysis, respectively.
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Influence of the black seed oil modified epoxy resin/biscycloaliphatic epoxide monomer weight ratio on thermal properties of photocrosslinked coatingsCite this paper: Vietnam J. Chem., 2023, 61(6), 732-740 Research ArticleDOI: 10.1002/vjch.202200194 Influence of the black seed oil modified epoxy resin/biscycloaliphatic epoxide monomer weight ratio on thermal properties of photocrosslinked coatings Nguyen Tien Dung2, Le Xuan Hien1*, Do Minh Thanh1 1 Institute for Tropical Technology (ITT), Vietnam Academy of Science and Technology (VAST) 18 Hoang Quoc Viet, Cau Giay, Hanoi 10000, Viet Nam 2 Hanoi National University of Education, 136 Xuan Thuy, Cau Giay, Hanoi 10000, Viet Nam Submitted November 3, 2022; Revised March 24, 2023; Accepted June 5, 2023Abstract The influence of the black seed oil modified epoxy resin (EBSO)/monomer 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexane carboxylate (BCDE) weight ratio in the coatings based on the compounds and photoinitiatortriarylsulfonium hexafluoroantimonate (TAS) on thermal properties of photocrosslinked coatings have been studied.The chemical structure of investigated UV-cured coatings was characterized by IR spectrometric analysis. Theirthermogravimetric (TG) and differential scanning calorimetry (DSC) behavior were determined by TG and DSCanalysis, respectively. It was shown that the testing atmosphere had almost no effect to the form of TG, DTG curves andlittle effect on value of weight degradation of investigated coatings. The volatilization of low molecular weightcompounds was observed in the range from room temperature to 360oC while the thermal degradation of the coatingsoccurred in the range from 360 to 455.5 oC. The augmentation of the EBSO/BCDE weight ratio from 20/80 to 80/20 ledto an increase of the degradation temperatures in the nitrogen atmosphere; extreme character of weight loss variation aswell as the reduction of glass transition temperatures of the coatings from 79.8oC (Tg1) and 83oC (Tg2) to 36.8 (Tg1) and38.9oC (Tg2), correspondingly. Keywords. UV- cured coatings, thermal properties, epoxy resin modified by black seed oil.1. INTRODUCTION flexible chains. Aromatic and heterocyclic polymers are more thermostable than the linear and fattyThermal stability is one of the most important cyclic hydrocarbon ones; the absence of hydrogenproperties of polymer materials from both academic atoms in macromolecules reduces thermo- oxidativeand practical sides. Based on the tight relation degradation of polymers; polymers having stiffbetween the thermal stability and composition, ladder figure chains are high thermostable sincestructure, compatibility of constituents of polymer polymer chains are not degraded while scission of amaterials one can deeper understand mechanism of single bond occurred.[1] The increase of crosslinkingtheir formation, structure as well as properly select degree enhances thermal stability of thermosettingtheir application fields from obtained information polymers. Photocrosslinked polymers often haveabout their heat resistance.[1] high thermal properties due to their high It was shown that the thermal stability of crosslinking density, especially the systemspolymer materials is affected by the content, containing bis-phenol A structure.[2]structure and compatibility of their constituents, Photocrosslinked tridimensional polymermethod of their synthesis and processing, bond networks containing bis-phenol A structure can beenergy of polymer structure, type of the bonds obtained by radical photopolymerization of systems(covalent or noncovalent), degree of unsaturation, based on epoxy diacrylate resins or by cationicfunctional groups, molecular weight, branch degree, photopolymerization of systems containing bis-crosslinking and crystalline degree.[1-11] The phenol A epoxy resins. It was reported that thefollowing relationship between structure of polymers introduction of rubber, vegetable or their derivativesand their thermal stability was reported: into the systems not only favors theMacromolecules with stiff chains are more photopolymerization process but also improvesthermostable than the ones of the same class with some properties of photocrosslinked networks like732 Wiley Online Library © 2023 Vietnam Academy of Science and Technology, Hanoi & Wiley-VCH GmbH 25728288, 2023, 6, Downloaded from https://onlinelibrary.wiley.com/doi/10.1002/vjch.202200194 by Readcube (Labtiva Inc.), Wiley Online Library on [01/05/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons LicenseVietnam Journal of Chemistry Le Xuan Hien et al.flexibility and stiffness.[5,6] Following the direction,UV-cured coatings containing bis-phenol A structureand vegetable residue were prepared byphotopolymerization of systems based on epoxyresin modified by various vegetable oils. It wasfound that cationic UV- curing of the coatings based ...