利用苯酚液化树皮制备环保耐水性木材胶粘剂及其表征

采用高效液相色谱(HPLC)和凝胶渗透色谱(GPC)方法结合胶合板评价,对6种酸性催化剂存在下的落叶松树皮苯酚液化产物,以及所制备的6种树皮胶粘剂进行表征,结果表明,液化催化剂的酸性对苯酚液化树皮产物的结合酚含量、活性功能基数目和分子量有着重要影响,进而影响所制备树皮胶粘剂的活性、凝胶时间、游离甲醛含量、耐水性和甲醛释放量;采用复合酸催化剂液化树皮所制备树皮胶的胶合强度、耐水性和甲醛释放量都优于硫酸单独做催化剂液化树皮制备的树皮胶,可用于环保耐水性结构胶合板的制备,并以硫酸/磷酸=1/1的复合酸催化剂为最佳。

Preparation and Characterization of Environmental-Safe and Water-Resistant Wood Adhesives Made from Liquefied Bark in Phenol

High performance liquid chromatography(HPLC),gel permeation chromatography(GPC) and plywood evaluation were employed to characterize the liquefied larch bark in phenol in the presence of 6 various acidic catalysts and the 6 resulting bark adhesives.The results indicated that the acidity of catalyst for bark liquefaction in phenol had great effects on the bond phenol content,active functional groups and molecular weight of liquefied larch bark,consequently,impacted on the reactivity,gel time,free formaldehyde content,water resistance and formaldehyde emission of bonded plywood.The plywood panels bonded with bark adhesives prepared from liquefied bark with combination catalyst had better bond strength, water resistance and formaldehyde emission than that with sulfuric acid alone as catalyst.Thus these bark adhesives can adapt to environmentaly safe and water-resistant plywood for structural use.The combination catalyst that is composed of sulfuric acid/phosphoric acid =1/1 is the most preferable for bark liquefaction and bark-adhesive preparation.