Resumen de Differential scanning calorimetry and dinamic mechanical analysis of phenol-resorcinol-formaldehyde resins
Justo Lisperguer, Cynthia Droguett Castillo, Beatriz Ruf, Mario Nuñez-Decap
Differential scanning calorimetry ( DSC ) and dinamic mechanical analysis ( DMA ) were use to study the curing reactions of two phenol - resorcinol- formaldehyde ( PRF ) adhesives with 15 and 25 % resorcinol content, synthesized in laboratory. The PRF resin with lower resorcinol content ( PRF1 ) shows a double exothermic peak ( 99.9 and 158.2 °C ) while PRF2 ,with greater resorcinol content ( 25 %) shows only one peak at 93.9 °C. The DMA storage modulus E' confirm the differences in the curing behavior of PRF adhesives. In the delamination resistance test during accelerated exposure only PRF2 with a greater content of resorcinol, fulfilled the ASTM D 2559 requirements for beams treated with two CCA retention levels. The cross-linking reactions was produced in the curing process at lower temperature in PRF2 , enhanced the adhesion durability to glulams treated with CCA preservatives
