Properties of molding plates made with various matrices impregnated with PF and liquefied wood-based PF resins

摘要

Phenol (P) and phenol-liquefied wood (LW; Cryptomeria japonica, Japanese cedar) have been reacted with formalin and ammonium hydroxide as a catalyst to prepare alcohol-soluble phenol-formaldehyde (PF) resins named PF and LWPF, respectively. The resins prepared were dehydrated, diluted with ethanol, and impregnated into wood powders, filter papers, and cloths. The PF resin-impregnated matrix materials were then hot-pressed to form molding plates (MP) and their properties were tested. Differential scanning calorimetric (DSC) analysis shows that both PF and LWPF behave as hot-melting resins and are able to further condensation reactions to form a set resin. However, the maximal temperatures of LWPF are shifted to a higher temperature range compared with PF. MPs made with LWPF-impregnated materials have poorer performance than that of PF. However, the bending strength of MP with filter paper is 96.8 MPa, which fits the request of CNS 10559. The MPs made of filter papers have the best mechanical properties followed by MPs with wood powders and cloths.