三階段合成法製備酚-間苯二酚-樹皮萃取物-甲醛共聚合樹脂及其性質

Phenol-Resorcinol-Bark Extractives-Formaldehyde Copolymer Resins Prepared with Three-stage Synthesis Method and Its Properties

李文昭(Wen-Jau Lee) ； 藍偉銓(Wei-Chuan Lan)

《林產工業》 26卷2期 (2007/06) Pp. 85-93

https://doi.org/10.6561/FPI.2007.26(2).2

摘要

本研究以相思樹及杉木樹皮之鹼萃取物為原料，利用三階段合成法製備酚-間苯二酚-樹皮萃取物-甲醛共聚合樹脂（PRTF）。合成時乃先將酚與甲醛於酸性環境下進行第一階段反應，形成novolak型PF預聚合樹脂，再於鹼性環境下加入樹皮萃取物使其與PF預聚合樹脂進行第二階段反應，最後再將間苯二酚加入進行第三階段反應。結果顯示添加適量的樹皮萃取物可改善酚-間苯二酚-甲醛共聚合樹脂（PRF）之常溫硬化性，但過多之萃取物添加量則將影響其常溫硬化能力。兩種樹種比較，以杉木樹皮萃取物為原料者有較佳的常溫硬化性。PRTF共聚合樹脂應用於木材常溫硬化膠合時，較佳之合成條件為酚／（間苯二酚+樹皮萃取物）之莫耳比[P/(R+T)]為1／1，間苯二酚／樹皮萃取物之重量比（R/T）為1／1，其共聚合樹脂之常態及耐水膠合強度膠均優於PRF樹脂，其中並以相思樹樹皮萃取物為原料者優於以杉木樹皮萃取物為原料者。

關鍵字

樹皮萃取物 ； 膠合性能 ； 共聚合反應 ； 酚-間苯二酚-樹皮萃取物-甲醛共聚合樹脂

並列摘要

The alkali extracts of Taiwan acacia (Acacia confusa) and China fir (Cunninghamia lanceolata) bark were used as the raw materials to prepare the phenol-resorcinol-bark extractives-formaldehyde copolymer resins (PRTF) with a three-stage synthesis method. The novolak PF prepolymer was prepared by reacting phenol with formaldehyde under acidic condition at the first stage. Then, the bark extractives were added under the alkaline condition to undergo the secondary stage of reaction. Finally, resorcinol was added to undergo the third stage of reaction. The results showed that adequate amount of bark extractives could improve the cold-setting properties of PRF resin, but over-loading would reduce its cold-setting capability. Comparison between Taiwan acacia and China fir, PRTF copolymer resins prepared from China fir bark extracts had better cold-setting properties than those from Taiwan acacia bark extracts. The suitable synthesis condition of PRTF copolymer resins was using the molar ratio of phenol to (resorcinol+bark extract) of 1/1 and the weight proportion of resorcinol to bark extracts of 50/50. The dry and wet bonding strength of PRTF copolymer resins were better than those of PRF resin. Comparison between Taiwan acacia and China fir, PRTF copolymer resin prepared from Taiwan acacia bark extracts had bonding strength better than that from China fir.

並列關鍵字

Bark extracts ； Bonding property ； Copolymerization ； Phenol-resorcinol-bark extractive-formaldehyde copolymer resins