Please use this identifier to cite or link to this item:
Effect of Formaldehyde/Phenol Molar Ratios on the Properties of Novolak-type PF Resins and Molding Plates
|關鍵字:||Molding plates;Novolak-type resins;Phenol-formaldehyde resins;Thermal analysis;酚醛樹脂;Novolak樹脂;成型板;熱分析||Project:||林業研究季刊, Volume 35, Issue 4, Page(s) 307-315.||摘要:||
本研究探討Novolak型酚醛樹脂（Phenol-formaldehyde resins；PF）合成時，甲醛／酚（F/P）之莫耳比（0.65/1、0.75/1、0.85/1）對合成樹脂性質之影響，並探討不同條件PF樹脂混合木粉、六亞甲基四胺、硬脂酸鋅所製作成型板之性質。由試驗結果顯示，Novolak型PF樹脂合成時，F/P莫耳比較高者，其合成樹脂之平均分子量較大，熔點較高；DSC（Differential scanning calorimetry）分析顯示添加六亞甲基四胺之Novolak型PF樹脂具熱硬化性，起始硬化反應溫度約130℃，F/P莫耳比較低者在熱硬化過程有較大之反應熱產生；Novolak型PF樹脂熱壓製作之成型板具備優異之尺寸安定性，隨F/P莫耳比提高，成型板之吸水率降低，內聚強度及抗彎強度增加，TGA（Thermogravimetry analysis）顯示成型板之熱裂解主要發生在250～400℃。
In this study, the influence of the molar ratio of formaldehyde to phenol (F/P), i.e. 0.65/1, 0.75/1 and 0.85/1, on the properties of Novolak-type phenol-formaldehyde resins (PF) were investigated. In addition, the properties of molding plates made with mixing various Novolak-type PF resins with wood powder, hexamethylenetetramine and zinc stearate were also demonstrated. The results show that Novolak-type PF resins prepared with higher F/P molar ratio had larger average molecular weight and higher melting point. DSC thermal analysis shows that Novolak-type PF resins had the characteristic of thermo-setting when blended with hexamethylenetetramine. It had the initial setting temperature at about 130℃. Novolak type PF resin that prepared with lower F/P molar ratio had larger reaction heat released during thermosetting. Molding plates made with Novolak-type resins by hot-pressing had good dimensional stability. Increasing the F/P molar ratio would decrease the water adsorption percentage and increase the internal bonding strength and bending strength of molding plates. TGA shows that the thermal degradation of molding plates mainly occurred at 250~400℃.
|Appears in Collections:||第35卷 第04期|
Show full item record
TAIR Related Article
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.