The gel time, pot life and curing properties of phenol-formaldehyde resin (PF) resins induced by single curing agents, namely methylolureas (MMU), propylene carbonate(PC), sodium carbonate (Na2CO3), and their hybrid were investigated. The results demonstrated that the gel times of PF resins induced by single curing agent and two kinds of their counterpart hybrid curing agents were shortened by at
... [Show full abstract] least 74s. However, the viscosities of PF resins in presence of PC and MMU+PC increased to 18 000 and 9 000 mPa·s from 178 mPa·s in 3h respectively, and the pot lifes were too short to meet the production requirement of 4 hours at least. The curing agents MMU+Na2CO3 had significant effect on lowering the onset and peak temperature of curing reaction. Thus the aim of fast curing of PF resin, and the needs of production were achieved. Therefore, the curing agent of MMU+Na2CO3 was suitable for fast curing at lower temperature in plywood production. ©, 2015, Editorial Board of «Chemistry and Industry of Forest Products». All right reserved.