A Study Of Usage Of Recycled Phenolic Resins

In this study the recyclability of the thermosetting phenolic resin had been systematically discussed. From the result of the UV spectrum of the ethanol solution of thermosetting phenolic resin and the IR spectra of the phenolic resin samples it could be found that, the solubility of the crushed waste phenolic resin in ethanol is larger than the untreated waste phenolic resin. The sample treated by adding crosslinking agent and air jet milling had the largest solubility in ethanol of the three. The conclusion couid be made that the air jet milling and join the cross-linking agent could effectively increase the active functional groups of the waste phenolic resin, so that the activity of the waste phenolic resin can be increased and can be reacted again, and so as to achieve the purpose of recycling the thermosetting phenolic resin.The study also found out that after crushing the thermosetting phenolic resin, sub-screening it step by step and adding a suitable crosslinking agent, the physical and chemical properties can be greatly improved when the sample been hot press mold or injection mold, at the secondary processing. Its reaction time, pressure and dwell time have a great impact on the physical and chemical properties of phenolic resin during processing. The air jet mill made the particle size smaller and increased the active functional groups of the phenolic resin on the surface area, making the reaction chance increases. The crosslinking agent can effectively increase the effective number of functional groups within the system; therefore enhanced the reactivity of the system, which made the performance of the recycling phenolic resin meet the needs of the processing. Compared hot press molding with injection molding, injection molding process is more simple and convenient, and the reaction time is shorter, it is more likely for industrial production. What is more the phenolic resin produced by injection molding, the tensile strength, notched impact strength, the nature of the specific gravity, water absorption, shrinkage and other characteristics are better than hot press molding. It can meet the industry requirements of the physical and chemical properties for the phenolic resin.