Synthesis of High-Molecular Weight Biobased Epoxy Resins: Determination of the Course of the Process by MALDI-TOF Mass Spectrometry

Abstract

The presented research shows the results of matrix-assisted laser desorption/ionization mass spectrometry, which was used as a means of monitoring the synthesis of novel high-molecular weight epoxy resins. The products were obtained by the reaction of epoxidized soybean oil (ESBO) and bisphenol A (BPA), using a modern and pro-ecological modification of the well-known method of the synthesis of epoxy resins, called “the epoxy fusion process”. On the basis of the obtained spectrograms, the manner in which substrates reacted with each other during the conducted synthesis was determined. Initially, after the reaction of the oxirane group of ESBO with the hydroxyl group of BPA, subsequent reactions occurred, involving other molecules of bisphenol and the remaining oxirane rings of epoxidized vegetable oil or the reaction of a free phenolic group with the following macromolecule of modified oil. It was found that the final product of the polyaddition (ESBO_BPA), obtained by the epoxy fusion process conducted in bulk, consists of macromolecules with various structure. First, smaller oligomers such as 1ESBO + 1BPA and ESBO + 2BPA were formed, and as the reaction proceeded, they rapidly reacted with each other forming larger macromolecules: 2ESBO + 2BPA, ESBO + 3BPA, 2ESBO + 3BPA, 3ESBO + 3BPA, and 3ESBO + 4BPA. On the basis of the course of the ESBO_BPA polyaddition process in the registered m/z range, it was found that 1ESBO + 1BPA tends to react with other substrates from the reacting mixture to create a linear product. Bisphenol A is a rigid element, which connects the elastic alkyl chains of epoxidized soybean oil in the obtained macromolecule.

Rheological Analysis of the Synthesis of High-Molecular-Weight Epoxy Resins from Modified Soybean Oil and Bisphenol A or BPA-Based Epoxy Resins

“…A two-step change in the value of epoxide number and weight average molecular weight was found. Based on previously published results of performed studies [9,10], it could be expected that numerous reactions occur, including reactions: (i) between -OH groups of bisphenol A/hydroxylated soybean oil with oxirane rings of epoxidized soybean oil/EPR 0162 low-molecular-weight epoxy resin (depending on the reagents used: ESBO_BPA/SMEG_EPR epoxy fusion process, respectively), resulting in the formation of a bimolecular intermediate product containing one molecule of ESBO/EPR0162 and one molecule of BPA/SMEG (ESBO + BPA or SMEG + EPR, respectively), as well as (ii) of newly formed products with other molecules of ESBO/SMEG or BPA/EPR0162, causing the creation of a high molecular weight epoxy product.…”

“…Our research team, based on the chemistry of the conventional epoxy resins synthesis from petrochemical raw materials, is conducting studies on novel epoxy materials obtained using modified vegetable oils that can partially replace petrochemical resources. Specifically, epoxidized oils can be substituted for low and average molecular weight epoxy resins, and hydroxylated ones can substitute for bisphenol A (BPA) in the fusion method of epoxy resins synthesis [8][9][10]. Additionally, the introduction of vegetable oils results in obtaining materials with better flexibility and a wider range of available cross-linking agents [11].…”

Blocked isocyanates as alternative curing agents for epoxy-polyurethane resins based on modified vegetable oils

“…Additionally, polyaddition products contained both hydroxyl and epoxide groups, which can be used in the process of their crosslinking (Table 2). Moreover, the course of the polyaddition process using modified soybean oil and the structure of obtained polyaddition products were determined (by means of MALDI-TOF spectrometry and NMR spectroscopy) and described in our previous research papers [16,26]. The final polyaddition product ESBO_BPA or SMEG_EPR, obtained by the epoxy fusion process conducted in bulk, consists of macromolecules with various structure.…”

“…It is possible to crosslink products of the epoxy fusion process with, e.g. diisocyanates, obtaining novel epoxy-polyurethane materials characterized by the properties resulting from the choice of the curing method [13,15,16]. Facing the present ecological requirements, we obtained materials using polyisocyanates such as: hexamethylene diisocyanate (HDI), diphenylmethane-diiscoyanate (MDI) and tolene-diisocyanate (TDI) [15], and also blocked isocyanates (Desmocap 11, Desmocap 12, Desmodur BL1265, Desmodur BL 3272 MPA, Desmodur BL 3175 SN, Desmodur BL 4265 SN and Desmodur PL 340 BA/SN).…”

Fabrication of photo-enzyme coupled catalysts with the desired electron transport channel for the high-efficiency synergic degradation of bisphenol A in water

“…With the rapid development of the global economy, pollution caused by industrial production has seriously threatened the survival of human beings and restricted the sustainable development of new energy. 1 As a major organic chemical raw material in industrial production, bisphenol A (BPA) is widely used in epoxy resins, 2 plastics, 3 medical devices, 4 and other consumer products. However, excessive use of BPA leads to unavoidable emissions, which can seriously harm the endocrine system and trigger cancer.…”