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用溶液共混法,制备了不同比例的硝化棉(NC)/端羟基聚醚(HTPE)物理共混物以及NC/HTPE/甲苯-2,4-二异氰酸酯(TDI)交联聚合物。用混合焓法研究了物理共混体系的相容性。用动态热机械分析研究了共混物的动态力学性能。用傅里叶变换红外(FT-IR)光谱法研究了NC和HTPE间的交联反应状态及分子间相互作用。结果表明,NC/HTPE是部分相容体系,且相容性与组成有关。随着HTPE比例的增加,共混体系的玻璃化温度逐渐降低,当NC含量为30%时,NC/HTPE物理共混体系的低温Tg为-9.8℃,交联体系的Tg为-1.4℃,相比NC的Tg有大幅度的降低。与NC/HTPE物理共混体系相比,化学交联可使NC和HTPE的相容性增加。交联后的异氰酸酯基在2270 cm-1处的特征吸收峰消失,说明交联反应比较完全。共混后NC的羟基和硝基的伸缩振动吸收峰均向低波数移动,说明NC和HTPE间存在氢键相互作用。交联之后,羟基和硝基的吸收峰移动减小,说明交联使NC和HTPE间的氢键作用被化学键作用部分取代。
Different proportions of nitrocellulose (NC) / poly (hydroxyethyl) ether (HTPE) blends and NC / HTPE / TDI crosspolymers were prepared by solution blending method. Mixed enthalpy method was used to study the compatibility of physical blends. The dynamic mechanical properties of blends were studied by dynamic thermo-mechanical analysis. The cross-linking reaction state and intermolecular interaction between NC and HTPE were studied by Fourier transform infrared (FT-IR) spectroscopy. The results show that NC / HTPE is a partially compatible system, and the compatibility is related to the composition. With the increase of the proportion of HTPE, the glass transition temperature of the blends decreased gradually. When NC content was 30%, the low temperature Tg of NC / HTPE blends was -9.8 ℃ and the Tg of the cross-linked system was -1.4 ℃. Compared with the NC Tg has a significant reduction. Compared with NC / HTPE physical blends, chemical crosslinking can increase the compatibility of NC and HTPE. The characteristic absorption peak at 2270 cm-1 of the isocyanate group disappeared after crosslinking, indicating that the cross-linking reaction is relatively complete. The stretching vibrational absorption peaks of hydroxyl and nitro groups of NC all shift to low wavenumbers after blending, which indicates that there exists hydrogen-bonding interaction between NC and HTPE. After crosslinking, the absorption peaks of hydroxyl and nitro groups decrease, which indicates that the hydrogen bonds between NC and HTPE are partly replaced by the chemical bonds.