The effects of temperature and humidity on phenol-formaldehyde resin bonding

✍ Scribed by Xiang-Ming Wang; Bernard Riedl; Alfred W. Christiansen; Robert L. Geimer

• Publisher: Springer
• Year: 1995
• Tongue: English
• Weight: 758 KB
• Volume: 29
• Category: Article
• ISSN: 0043-7719
• DOI: 10.1007/bf00202085

✦ Synopsis

The effects of temperature and relative humidity on phenol-formaldehyde resin bonding were evaluated. Two flakes in a lap-shear configuration were bonded under an environment of controlled temperature (110 ~ 120 ~ 130 ~ 140 ~ and relative humidity (41%, 75%, 90%) for a series of time periods (0.25 to 16 min). The lap-shear specimens were then shear-tested on a mechanical testing machine and the results were used to establish a family of bond strength development curves at each temperature and level of relative humidity. At 1 I0 ~ the higher relative humidity appeared to retard resin bonding. The effects of relative humidity diminished as temperature increased to 140 ~ Bond strength development was chemical ratecontrolled. The rate of bond strength development at each relative humidity follows a first order reaction mechanism. The activation energy of resin-wood bonding, determined by bonding kinetics, was higher than that of resin alone, determined by differential scanning calorimetry. This comparison indicates that to form a strong resin-wood bond, a higher energy level might be required.