Study of preparation and properties of environmentally friendly phenolic resin for mining

In order to solve the problem of formaldehyde release from the traditional phenolic foam (PF) in the process of coal mine filling and plugging. In this paper, the effect of different factors on the efficiency of formaldehyde trapping agents were studied by adding formaldehyde trapping agents containing amino compounds after PF synthesis. The effect of formaldehyde trapping agents on the performance of resin was investigated. The results showed that the addition of formaldehyde trapping agents could greatly reduce the residual formaldehyde content in phenolic resin. Fourier‐transform infrared spectroscopy (FTIR) data showed that the addition of formaldehyde trapping agent not only successfully prepared PF, but also produced a stable formaldehyde trapping agent product. Compared with the unmodified PF, the pore size and foaming rate of the modified PF decreased in varying degrees, and the foaming temperature also decreased in varying degrees. Among them, urea modified phenolic resin (PUF) had the highest formaldehyde removal efficiency. It had the t lowest heat release during combustion and the foam pore size was large and uniform. In addition, through the application of urea‐modified PF in the goaf return air corner fissure sealing application, it was found that the CO concentration in the goaf maintained at the lowest state of 0.002%. It has reached the national industry standard of polymer gas plugging materials and conforms to the green development concept in the field of coal mine fire prevention. Reaction mechanism between formaldehyde trapping agent and formaldehyde.