PU樹脂的NCO／OH莫耳比對ER／PU及ER／LWPU摻合樹脂性質之影響

The effect of the NCO/OH molar ratio of PU resin on the properties of ER/PU and ER/LWPU blend resins

環氧樹脂（Epoxy resin; ER）為現今應用最廣泛的合成樹脂之一，然有性質硬脆的缺點，如何提高其韌性為重要的課題。本研究以Epon 828為ER樹脂，聚四甲基醚二醇（Polytetramethylene ether glycol; PTMG）及液化木材（Liquefied wood; LW）為聚胺基甲酸酯樹脂（Polyurethane resin; PU）之多元醇原料，氫化苯基甲烷二異氰酸酯（Hydrogenated diphenylmethane 4,4-diisocyanate; H12-MDI）為其異氰酸酯原料，探討PU樹脂之NCO/OH莫耳比對ER/PU及ER/LWPU摻合樹脂性質之影響。由結果得知，摻合樹脂同時具備ER與PU樹脂組成分，動態熱機械分析（Dynamic mechanical analysis; DMA）分析顯示此兩種樹脂形成互穿高分子網狀結構（Interpenetrating polymer networks; IPNs）。ER/PU及ER/LWPU比較，前者有較大的斷裂撓曲量及破壞能量，後者則有較大的彈性模數、硬度及熱活動性。不同NCO/OH莫耳比比較，ER/PU摻合樹脂以莫耳比1/1，ER/LWPU以莫耳比1/1及1.5/1者有較大的機械性能。而隨NCO/OH莫耳比提高，摻合樹脂內部結構之均質性降低，熱重分析（Thermal gravimetric analysis; TGA）分析之熱抵抗性提高。

Epoxy resin (ER) is one of the most widely used synthetic resins today. However, it has the shortcomings of being hard and brittle. How to improve the toughness of ER is an important issue. In this study, Epon 828 was used as the ER resin, polytetramethyl ether glycol (PTMG) and liquefied wood (LW) were used as the polyol raw materials for the polyurethane resin (PU), and hydrogenated diphenylmethane 4,4-diisocyanate (H_(12)-MDI) was used as the isocyanate raw material. The effect of the molar ratio of NCO/OH of PU resin on the properties of ER/PU and ER/LWPU blend resins was investigated. The results showed the blended resins had both ER and PU resin composition. Dynamic mechanical analysis (DMA) showed that these two resins formed an interpenetrating polymer networks (IPNs). Compared with ER/PU and ER/LWPU, the former had larger breaking deflection and fracture energy, while the latter had higher elastic modulus, hardness and thermal activity. Compared with different NCO/OH molar ratios, the ER/PU blended resin had a molar ratio of 1/1, and ER/LWPU had a molar ratio of 1/1 and 1.5/1, which had greater mechanical properties. As the NCO/OH molar ratio increased, the homogeneity of the internal structure of the blended resin decreased, and the thermal resistance obtained by thermal gravimetric analysis (TGA) increased.