Search Results (3)

The epoxy resin-based (ESB) intumescent flame-retardant coatings were modified with 1,4-butanediol diglycidyl ether (14BDDE) and butyl glycidyl ether (BGE) as diluents and T403 and 4,4′-diaminodiphenylmethane (DDM) as curing agents, respectively. The effects of different diluents and curing agents on the flame-retardant and mechanical properties, as well as the composition evolution of the coatings, were investigated by using large-plate combustion, the limiting oxygen index (LOI), vertical combustion, a cone calorimeter, X-ray diffraction, FTIR analysis, a N₂ adsorption and desorption test, a scanning electron microscope (SEM), a tensile strength test, and a viscosity test. The results showed that the addition of 14BBDE and T403 promoted the oxidation of B₄C and the formation of boron-containing glass or ceramics, increased the residual mass of char, densified the surface char layer, and increased the specific surface area of porous residual char. When their dosage was 30%, ESB-1T-3 coating exhibited the most excellent flame-retardant properties. During the 2 h large-plate combustion test, the backside temperature was only 138.72 °C, without any melting pits. In addition, the peak heat release rate (PHRR), total heat release rate (THR), total smoke production (TSP), and peak smoke production (PSPR) were reduced by 13.15%, 13.9%, 5.48%, and 17.45%, respectively, compared to the blank ESB coating. The LOI value reached 33.4%, and the vertical combustion grade was V-0. In addition, the tensile strength of the ESB-1T-3 sample was increased by 10.94% compared to ESB. In contrast, the addition of BGE and DDM promoted the combustion of the coating, affected the ceramic process of the coating, seriously affected the formation of borosilicate glass, and exhibited poor flame retardancy. The backside temperature reached 190.93 °C after 2 h combustion. A unified rule is that as the amount of diluent and curing agent increases, the flame retardancy improves while the mechanical properties decrease. This work provides data support for the preparation and process optimization of resin-based coatings. Full article

In recent years, the prominence of conformance control technology in heavy oil steam flooding has significantly increased in oilfield development. However, the high-temperature demands of heavy oil steam flooding require more resilient plugging agents. Resin-based plugging agents, known for their exceptional temperature resistance and strength, have emerged as a viable solution within this domain. Yet, they face issues like rapid curing at high temperatures and limited sealing reach. Thus, we introduce a novel approach: epoxy resin gel (EHRB), consisting of epoxy resin (ER) as the curing agent, urotropine (HMTA) and pyrocatechol (RO) as cross-linking agents, and n-butyl glycidyl ether (BGE) as a diluent. EHRB gels at 130 °C in 5.4 h, with curing commencing at 160 °C, extending resin curing time and expanding the sealing radius. This study assessed EHRB’s performance and high-temperature stability through displacement experiments, TGA, and DSC analysis. The results indicate that the EHRB has low viscosity, high compressive strength, and minimal mass loss at high temperatures. At 260 °C, the mass loss is less than 15%. The plugging rate exceeds 90%, and it can withstand steam flushing for over 6 PV. Additionally, it demonstrates a 17% improvement in EOR. EHRB demonstrates outstanding capabilities in proficient channel control for heavy oil steam flooding, offering vital technical support for conformance control in this challenging environment. Full article

Self-healing cementitious composites have been developed by using microcapsules. In this study, the effect of the healing agent on the crosslinking and curing reaction kinetics was analyzed. The effect of the diluent n-butyl glycidyl ether (BGE) on the reaction was investigated for five fractions, namely 10.0%, 12.5%, 15.0%, 17.5%, and 20.0% mass fractions to epoxy resin. The Kissinger and Crane equations were used to obtain the activation energy and reaction order with different mass fractions of diluent, as well as the kinetic parameters of the curing reaction. The optimal fraction of BGE was determined as 17.5%. Likewise, the effect of the curing agent MC120D on the reaction kinetics was investigated for 10%, 20%, 30%, 40%, and 50% mass fractions to the diluted epoxy resin. The optimal fraction was determined as 20%. The mechanism of the curing reaction with the healing agent was investigated. The infrared spectra of the cured products of 20% MC120D with BGE/E51 (0.0%, 12.5%, 15.0%, 20.0%, 100%) were analyzed. It is shown that not only the epoxy resin E-51 was cured, but also that the BGE was involved in the cross-linking reaction of the epoxy resin E-51 with MC120D. Full article