Acceleration of the Cure of Phenol-Formaldehyde Adhesives.

• Main Authors: CHANGCHENGHSUAN, 張正璇
• Other Authors: 林正榮
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/98219316554431270484

碩士 === 國立屏東科技大學 === 木材工業系 === 92 === The objectives of this study are two-fold. The first one is to investigate the hardening behaviors of the resol PF adhesives by adding different kinds of accelerators. Another is to study the curing properties of high-ortho PF adhesives. From the experiment result of resol PF adhesives, the addition of accelerator can shorten the gel time. The gel time decreases with the increase of the amount of accelerator. From the result of differential scanning calorimetry（DSC）, the logarithm of reaction velocity（ln k）has shown a linear relationship with the reciprocal of the operating absolute temperature（1/T）for all resin adhesives of synthetic conditions. And all the hot hardening reactions are all linear. Moreover, the highest temperature of exothermic peak as well as the curing reaction heat would become lower as the accelerators were added in the glue formulation. As for the bonding properties of the resol PF adhesives used in plywood making, plywood made with conditions that reduced hot pressing time from 60 sec/mm to 40 sec/mm and platen temperature from 150 ℃ to 130 ℃ could meet the requirements specified in CNS-1349. Therefore, the conclusion can be made that three types of accelerators used in this study could shorten the pressing time for manufacturing plywood. And the acceleration effect of sodium carbonate is better than propylene carbonate and triacetin. From the experiment result of high-ortho PF resins, the ortho orientation effect increase with and the gel time decrease with the increase of the amount of catalyst. From the result of differential scanning calorimetry（DSC）, the logarithm of reaction velocity（ln k）has shown a linear relationship with the reciprocal of the operating absolute temperature（1/T）for all high-ortho PF resins. And the highest temperature of exothermic peak as well as the curing reaction heat would become lower as the catalyst was used in the resin preparation. But their highest temperature of exothermic peak was higher than that of resol PF resin. As for the bonding properties of high-ortho PF resins used for plywood could not meet the requirements specified in CNS-1349.