Synthesis and curing performance of a novel bio‐based epoxy monomer from soybean oil

Abstract

A novel bio‐based epoxy monomer (EP) was obtained from the reaction of modify soybean oil and epichlorohydrin (ECH). And EP blended with bisphenol‐A epoxy oligomer (DGEBA) to form the epoxy networks using triethylene tetramine as curing agent. The weight fraction of EP affects the performance of epoxy networks have been studied. The structures of the monomers and networks were studied by Fourier transformation infrared spectrometer (FTIR), and were consistent with the theoretical structures. Thermo‐gravimetric analysis (TG) and differential scanning calorimetry analysis (DSC) were used to determine the thermal properties of the epoxy networks, indicating that glass transition temperature (Tg) and thermal stability decreased with increasing EP content. Mechanical properties analysis showed that the elongation at break and impact strength of the epoxy networks increased with the increasing EP content, while the tensile strength decreased. Dynamic non‐isothermal curing test and scanning electron microscope (SEM) analysis revealed that there was no obvious phase separation and formed homogeneous crosslinking network structure. The properties of the epoxy networks were hard and brittle in low EP content, and presented strong flexible or soft flexible in high EP content.Practical applications:Soybean oil is one of the most interesting environmental resources for the synthesis of monomers, because of the aliphatic chain and functional groups contribute as a primary element to the backbone of polymer. It has received much attention as a renewable resource to replace petroleum resource for preparing chemicals and polymers, due to its environmental advantages, renewable and economic. The bio‐based epoxy resin can be used to modify the commercial bisphenol‐A epoxy resin to overcome the weaknesses of brittleness of the cured networks. As a novel epoxy monomer, it can be used in many fields which the traditional epoxy resins were used, such as paint, coatings, adhesives, electronic materials, and structural materials. Also, it can be used as a modifier to modify other industrial epoxy resins, due to the flexible aliphatic chain structure and low viscosity property. The bio‐based may degrade after discarding and come into environmental cycle.Soybean oil has received much attention as a renewable resource to replace petroleum resource for preparing chemicals and polymers, due to its environmental advantages, renewable and economic. In this paper, a novel polyols is derived from soybean oil and used for the preparation of aliphatic epoxy monomer. And then the bio‐based epoxy monomer is used to modify the commercial bisphenol‐A epoxy oligomer to overcome the weaknesses of brittleness of the cured networks. The epoxy monomer and epoxy networks prepared from soybean oil are environmentally friendly materials. It may degrade after discarding and come into environmental cycle.