添加印度苦楝油於蓖麻油基聚胺甲酸酯複合材料製造及性質之影響

The influence of adding neem oil on manufacture and properties of castor oil-based polyurethane composite

"本研究將蓖麻油（Castor oil）作為生質基多元醇，異氰酸酯Desmodur N為硬化劑，以NCO/OH莫耳比1.5及2.0製備生質基聚胺基甲酸酯樹脂（Polyurethane; PU），發泡劑及催化劑分別為水及二月桂酸二丁基錫，並添加蓖麻油之0、10和20 wt%比例之印度苦楝油（Azadirachta indica, Neem oil；印楝油），以國產中小徑杉木（Cunninghamia lanceolata）為粒片基材，設定PU膠合劑／粒片重量比為1.2和板材密度為500 kg/m^3，以熱壓方式製備低密度複合板材，並測定其基本性質、內聚強度（Internal bonding strength）及尺寸安定性，探討添加印度苦楝油對複合材料性質之影響。結果顯示添加印楝油比例增加則延長PU之反應時間，未使用界面活性劑可製造型態完整發泡體和複合材料，本研究製造之複合材料具低平衡含水率（Equilibrium moisture content）及高尺寸安定性（Dimensional stability），印楝油比例增加可降低板材吸濕性，內聚強度符合CNS 2215標準，添加印楝油複合材料內聚強度高於對照組，證明其促進膠合劑與粒片結合，印楝油可做為生質基添加劑，增強複合材料之性質。"

"In this study, castor oil and Desmodur N was used as a biobased polyol and an isocyanate to prepare biobased polyurethane (PU) resin with NCO/OH molar ratio of 1.5 and 2.0. The PU-base composites were manufactured by hot pressing with the density set to 500 kg/m^3. The process use water as the foaming agent, dibutyltin dilaurate as the catalyst, and China fir (Cunninghamia lanceolata) as the wood particle. The weight of neem oil was set to 0, 10 and 20 wt% of castor oil. Weight ratios of wood particles/PU resin were 1.2/1. The basic properties, internal bonding strength, and dimensional stability of the composites were measured to investigate the effect of neem oil addition on the properties. The results showed that adding neem oil increases the reaction time of PU resin and helps to manufacture complete foams and composite materials without using surfactants. The PU-based composites have low moisture content and good dimensional stability. Increasing neem oil ratio reduced the moisture absorption. Internal bond strength performed in accordance with CNS 2215 standard. The internal bond strength of the neem oil-added composite was higher than that of the control group, indicating that it promoted the binding of the adhesive to the wood particle and improved the properties of the composite material."