農林廢料製造木材膠合劑之研究（IV）酚－相思樹樹皮抽出物－甲醛共聚合膠劑之應用

Studies on the Manufacture of Wood Adhesives from the Residues of Agriculture and Forest (N)-The Application of Adhesives of Phenol-Acacia Bark Extractive-Formaldehyde Copolymers

李文昭(Wen-Jau Lee) ； 劉正字(Cheng-Tzu Liu)

《林產工業》 15卷2期 (1996/06) Pp. 251-270

https://doi.org/10.6561/FPI.1996.15(2).5

摘要

本研究乃探討相思樹樹皮之鹼抽出物與酚、甲醛行共聚合反應製造木材膠合劑之可行性。其試驗所得重要結果可歸納如下：1.PF樹脂之固形分含量、pH值、粘度、游離甲醛含量、鹼含量、比重及膠化時間等均受其合成時所採用之NaOH/P莫耳比所影響。NaOH使用量較高時其耐水膠合強度較低。2.酚－抽出物－甲醛共聚合樹脂之膠化時間隨NaOH使用量增加而延長，隨抽出物取代量增加而明顯縮短。固形分含量、pH值、鹼含量、比重等則隨抽出物取代量增加而降低。其膠合性質以合成時NaOH/P為0.7者較佳，耐沸水膠合強度在抽出物取代量40%時仍可達10.2Kgf/cm^2，常態膠合強度則在抽出物取代量至60%時仍有良好之膠合效果。3.抽出物在共聚合反應過程中將參與反應之進行，然其硬化時產生之縮合程度較PF樹脂為低。

關鍵字

酚甲醛樹脂 ； 酚－抽出物－甲醛共聚合樹脂 ； 合板 ； 膠合強度

並列摘要

This study we investigated the probabilities of wood adhesives made from copolymerization of phenol, alkali extractive of acacia bark and formaldehyde. The results were summarized as follows: 1. The solid content, pH value, viscosity, free formaldehyde content, alkali content, specific gravity and gelation time of PF resins were all affected by the molar ratio of NaOH to phenol which used at the resin synthesis. More the NaOH used, lower the water resistance of the bonding strength was. 2. Increment of the amount of NaOH would increase the gelation time of phenol-extractive-formaldehyde copolymer resins (PTF). When the amount of extractive replacement increased, the gelation time of PTF would shorten and the solid content, pH value, alkali content and specific gravity would be descreased. Copolymer of PTF with the molar ratio of NaOH/P of 0.7 had better bonding properties than the others. Its boiling bonding strength was 10.2Kgf/cm^2 at 40% extractives replacement, and it had good dry bonding strength even the extractives replacement up to 60%. 3. Extractives would take part in the reaction of the copolymerization of PTF resins, but the condensation degree of cured resins of PTF would lower than PF resins.

並列關鍵字

phenol-formaldehyde resin ； phenol-extractive-formaldehyde copolymer ； plywood ； bonding strength